記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) are widely used in the orofacial region. Furthermore, quantitative analyses have proven useful. However, a few reports have described the correlation between DWI-derived parameters and DCE-MRI-derived parameters, and the results have been controversial. PURPOSE: To evaluate the correlation among parameters obtained by DWI and DCE-MRI and to compare them between benign and malignant lesions. MATERIAL AND METHODS: Fifty orofacial lesions were analysed. The apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudodiffusion coefficient (D*) and perfusion fraction (f) were estimated by DWI. For DCE-MRI, TK model analysis was performed to estimate physiological parameters, for example, the influx forward volume transfer constant into the extracellular-extravascular space (EES) (Ktrans) and fractional volumes of EES and plasma components (ve and vp). RESULTS: Both ADC and D showed a moderate positive correlation with ve (ρ = 0.640 and 0.645, respectively). Ktrans showed a marginally weak correlation with f (ρ = 0.296), while vp was not correlated with f or D*; therefore, IVIM perfusion-related parameters and TK model perfusion-related parameters were not straightforward. Both D and ve yielded high diagnostic power between benign lesions and malignant tumours with areas under the curve (AUCs) of 0.830 and 0.782, respectively. CONCLUSION: Both D and ve were reliable parameters that were useful for the differential diagnosis. In addition, the true diffusion coefficient (D) was affected by the fractional volume of EES.

DOI： 10.1177/20584601241244777

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: This study aimed to compare assessments by radiologists, artificial intelligence (AI), and quantitative measurement using synthetic MRI (SyMRI) for differential diagnosis between astrocytoma, IDH-mutant and oligodendroglioma, and IDH-mutant and 1p/19q-codeleted and to identify the superior method. METHODS: Thirty-three cases (men, 14; women, 19) comprising 19 astrocytomas and 14 oligodendrogliomas were evaluated. Four radiologists independently evaluated the presence of the T2-FLAIR mismatch sign. A 3D convolutional neural network (CNN) model was trained using 50 patients outside the test group (28 astrocytomas and 22 oligodendrogliomas) and transferred to evaluate the T2-FLAIR mismatch lesions in the test group. If the CNN labeled more than 50% of the T2-prolonged lesion area, the result was considered positive. The T1/T2-relaxation times and proton density (PD) derived from SyMRI were measured in both gliomas. Each quantitative parameter (T1, T2, and PD) was compared between gliomas using the Mann-Whitney U-test. Receiver-operating characteristic analysis was used to evaluate the diagnostic performance. RESULTS: The mean sensitivity, specificity, and area under the curve (AUC) of radiologists vs. AI were 76.3% vs. 94.7%; 100% vs. 92.9%; and 0.880 vs. 0.938, respectively. The two types of diffuse gliomas could be differentiated using a cutoff value of 2290/128 ms for a combined 90th percentile of T1 and 10th percentile of T2 relaxation times with 94.4/100% sensitivity/specificity with an AUC of 0.981. CONCLUSION: Compared to the radiologists' assessment using the T2-FLAIR mismatch sign, the AI and the SyMRI assessments increased both sensitivity and objectivity, resulting in improved diagnostic performance in differentiating gliomas.

DOI： 10.1007/s00234-024-03288-0

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: The cortical high-flow sign with the non-enhancing area was reportedly found to be more frequent with oligodendroglioma, IDH-mutant and 1p/19q codeleted (ODG IDHm-codel) than with IDH-wildtype or astrocytoma, IDH-mutant on arterial spin labeling (ASL) in diffuse gliomas. This study aimed to compare the identification rate of the cortical high-flow sign on ASL in patients with ODG IDHm-codel to that on dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI). METHODS: Participants consisted of 32 adult ODG IDHm-codel patients with pathologically confirmed. Subtraction images were generated from paired control and label images on ASL. For DSC, dynamic T2*-weighted perfusion weighted images were obtained after pre-bolus of gadolinium-based contrast agent. Regional cerebral blood flow/volume maps were generated based on the concentration-time curve and arterial input function. Tumor-affecting cortices without contrast enhancement on conventional MR imaging were targeted. The identification rate of the cortical high-flow sign was compared between ASL and DSC using the Pearson's Chi-Square test. RESULTS: Frequency of the cortical high-flow sign was significantly higher on ASL (18/32, 56.3&#37;; p < 0.001) than on DSC (5/32, 15.6&#37;). All cases with the positive cortical high-flow sign on DSC were identified on ASL. CONCLUSION: ASL effectively identifies the cortical high-flow sign in ODG IDHm-codel, surpassing DSC in identification rates.

DOI： 10.1007/s00234-023-03267-x

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Hypomyelination of early myelinating structures (HEMS) has recently been defined as a new genetic disorder accompanied by clinical and MR imaging characteristics. However, no studies have focused on diffusion-weighted imaging (DWI) findings of HEMS. We would like to propose a "sheep sign," which is formed by DWI hyperintensity in the medial medullary lamina along with alternating high-low-high (HLH) intensity stripes in the posterior limb of the internal capsule. We believe the presence of the "sheep sign" on DWI in combination with alternating HLH intensity stripes may be a valuable tool for diagnosing HEMS.

DOI： 10.1177/19714009231224419

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To assess the reproducibility of ADC, T1, T2, and proton density (PD) measurements on the cortex across the entire brain using high-resolution pseudo-3D diffusion-weighted imaging using echo-planar imaging with compressed SENSE (EPICS-DWI) and 3D quantification with an interleaved Look-Locker acquisition sequence with T2 preparation pulse (3D-QALAS) in normal healthy adults. METHODS: Twelve healthy participants (median age, 33 years; range, 28-51 years) were recruited to evaluate the reproducibility of whole-brain EPICS-DWI and synthetic MRI. EPICS-DWI utilizes a compressed SENSE reconstruction framework while maintaining the EPI sampling pattern. The 3D-QALAS sequence is based on multi-acquisition 3D gradient echo, with five acquisitions equally spaced in time, interleaved with a T2 preparation pulse and an inversion pulse. EPICS-DWI (b values, 0 and 1000 s/mm2) and 3D-QALAS sequence with identical voxel size on a 3.0-T MR system were performed twice (for test-retest scan). Intraclass correlation coefficients (ICCs) for ADC, T1, T2, and PD for all parcellated volume of interest (VOI) per subject on scan-rescan tests were calculated to assess reproducibility. Bland-Altman plots were used to investigate discrepancies in ADCs, T1s, T2s, and PDs obtained from the two MR scans. RESULTS: The ICC of ADCs was 0.785, indicating "good" reproducibility. The ICCs of T1s, T2s, and PDs were 0.986, 0.978, and 0.968, indicating "excellent" reproducibility. CONCLUSION: The combination of EPICS-DWI and 3D-QALAS sequences with identical voxel size could reproducible ADC, T1, T2, and PD measurements for the cortex across the entire brain in healthy adults.

DOI： 10.1016/j.ejro.2023.100516

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Arterial spin labeling (ASL) is a noninvasive imaging technique that labels the proton spins in arterial blood and uses them as endogenous tracers. Brain perfusion imaging with ASL is becoming increasingly common in clinical practice, and clinical applications of ASL for intracranial magnetic resonance angiography (MRA) have also been demonstrated. Unlike computed tomography (CT) angiography and cerebral angiography, ASL-based MRA does not require contrast agents. ASL-based MRA overcomes most of the disadvantages of time-of-flight (TOF) MRA. Several schemes have been developed for ASL-based MRA; the most common method has been pulsed ASL, but more recently pseudo-continuous ASL, which provides a higher signal-to-noise ratio (SNR), has been used more frequently. New methods that have been developed include direct intracranial labeling methods such as velocity-selective ASL and acceleration-selective ASL. MRA using an extremely short echo time (eg, silent MRA) or ultrashort echo-time (TE) MRA can suppress metal susceptibility artifacts and is ideal for patients with a metallic device implanted in a cerebral vessel. Vessel-selective 4D ASL MRA can provide digital subtraction angiography (DSA)-like images. This review highlights the principles, clinical applications, and characteristics of various ASL-based MRA techniques. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 2.

DOI： 10.1002/jmri.29119

記述言語：英語  

DOI： 10.1007/s00234-023-03228-4

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: Amide proton transfer (APT) imaging may detect changes in tissues' pH based on the chemical exchange saturation transfer (CEST) phenomenon, and thus it may be useful for identifying the penumbra in ischemic stroke patients. We investigated the effect of saturation pulse duration and power on the APT effect in phantoms with different pH values. METHODS: Five samples were prepared from a 1:10 solution of egg-white albumin in phosphate-buffered saline at pH 6.53-7.65. The APT signal intensity (SI) was defined as asymmetry of the magnetization transfer ratio at 3.5 ppm. We measured the APT SIs in the egg-white albumin samples of different pH values with saturation pulse durations of 0.5, 1.0, 2.0, and 3.0 sec and saturation pulse powers of 0.5, 1.5, and 2.5 μT. The relative change in the APT SI in relation to the saturation duration and power at different pH values was defined as follows: (APT SI each saturation pulse - APT SI shortest or weakest pulse)/APT SIshortest or weakest pulse. The dependence of the APT SI on pH and the relative change in the APT SI were calculated as the slope of the linear regression. RESULTS: The lower the pH, the larger the relative change in the APT SI, due to the change in saturation pulse duration and power. The APT SI was highly correlated with the pH at all saturation pulse durations and powers. CONCLUSION: The influence of saturation duration and power on the APT effect was greater at lower pH than higher pH. The combination of saturation pulse ≥ 1.0 s and power ≥ 1.5 μT was useful for the sensitive detection of changes in APT effects in the egg-white albumin samples with different pH values.

DOI： 10.2463/mrms.mp.2021-0109

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Alexithymia, a personality trait characterized by difficulties in identifying and expressing their emotions despite having a range of emotional experiences, can impact individuals' stress coping mechanisms. While many studies have investigated brain functions associated with specific tasks in relation to emotion processing, research focusing on resting-state brain functions has been limited. Thus, the aim of this study was to investigate the relationship between alexithymia and brain function by analyzing arterial spin labeling (ASL) data obtained during the resting state. METHODS: A brain structural and functional imaging study was conducted on 42 healthy adult men and women using ASL and the 20-item Toronto Alexithymia Scale (TAS-20) questionnaire survey. Cerebral blood flow and functional connectivity values were calculated for regions of interest in the default mode network, saliency network, and central executive network from the ASL data. Correlation analysis was performed with TAS20 scores, and partial correlation analysis was conducted to control for anxiety and depression. RESULTS: The functional connectivity analysis revealed a negative correlation between the functional connectivity of the right insular cortex and left anterior cingulate cortex and the total score of TAS, as well as difficulty identifying feelings and difficulty describing feeling subscores, indicating that the higher the scores, the weaker the functional connectivity between these regions (T = -3.830, p = 0.0013, R = -0.5180). This correlation remained significant even after controlling for anxiety and depression using partial correlation analysis. CONCLUSION: The present study revealed differences in the activity of the Saliency Network at rest as measured by ASL, which were independent of anxiety and depression, and varied depending on the severity of alexithymia. This functional change may underlie the neural basis of decreased emotional processing observed in alexithymia. These findings may contribute to the elucidation of the neural mechanisms of alexithymia, which can lead to social impairments, and suggest the usefulness of ASL measurement as a biomarker of alexithymia.

DOI： 10.1186/s40101-023-00336-1

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Recent evidence suggests that broad brain regions, not limited to the fronto-striato-thalamo-cortical circuit, play an important role in motor response inhibition. However, it is still unclear which specific key brain region is responsible for impaired motor response inhibition observed in obsessive-compulsive disorder (OCD). We calculated the fractional amplitude of low-frequency fluctuations (fALFF) and measured response inhibition ability using the stop-signal task in 41 medication-free patients with OCD and 49 healthy control (HC) participants. We explored the brain region that shows different association between the fALFF and the ability of motor response inhibition. Significant differences in fALFF associated with the ability of motor response inhibition were identified in dorsal posterior cingulate cortex (PCC). There was a positive correlation between increased fALFF in the dorsal PCC and impaired motor response inhibition in OCD. In the HC group, there was a negative correlation between the two variables. Our results suggest that the magnitude of resting-state blood oxygen level-dependent oscillation of the dorsal PCC is a key brain region for the underlying mechanisms of impaired motor response inhibition in OCD. Future studies should examine whether this characteristic of dorsal PCC affects other large-scale networks responsible for motor response inhibition of OCD.

DOI： 10.1016/j.pscychresns.2023.111669

記述言語：英語   掲載種別：研究論文（学術雑誌）  

This study aimed to investigate whether arterial spin labeling (ASL) features allow differentiation of oligodendroglioma, IDH-mutant and 1p/19q-codeleted (IDHm-codel) from diffuse glioma with IDH-wildtype (IDHw) or astrocytoma, IDH-mutant (IDHm-noncodel). Participants comprised 71 adult patients with pathologically confirmed diffuse glioma, classified as IDHw, IDHm-noncodel, or IDHm-codel. Subtraction images were generated from paired-control/label images on ASL and used to assess the presence of a cortical high-flow sign. The cortical high-flow sign was defined as increased ASL signal intensity within the tumor-affecting cerebral cortex compared with normal-appearing cortex. Regions without contrast enhancement on conventional MR imaging were targeted. The frequency of the cortical high-flow sign on ASL was compared among IDHw, IDHm-noncodel, and IDHm-codel. As a result, the frequency of the cortical high-flow sign was significantly higher for IDHm-codel than for IDHw or IDHm-noncodel. In conclusion, the cortical high-flow sign could represent a hallmark of oligodendroglioma, IDH-mutant, and 1p/19q-codeleted without intense contrast enhancement.

DOI： 10.1007/s00234-023-03186-x

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: Isocitrate dehydrogenase (IDH)-wildtype diffuse astrocytic glioma with telomerase reverse transcriptase (TERT) promoter mutation is defined as glioblastoma by the WHO 2021 criteria, revealing that TERT promotor mutation is highly associated with tumor aggressiveness. The aim of this study was to identify features from MR spectroscopy (MRS) and multi-exponential models of DWI distinguishing wild-type TERT (TERTw) from TERT promoter mutation (TERTm) in IDH-wildtype diffuse astrocytic glioma. METHODS: Participants comprised 25 adult patients with IDH-wildtype diffuse astrocytic glioma. Participants were classified into TERTw and TERTm groups. Point-resolved spectroscopy sequences were used for MRS data acquisition. DWI was performed with 13 different b-factors. Peak height ratios of NAA/Cr and Cho/Cr were calculated from MRS data. Mean apparent diffusion coefficient (ADC), perfusion fraction (f), diffusion coefficient (D), pseudo-diffusion coefficient (D*), distributed diffusion coefficient (DDC), and heterogeneity index (α) were obtained using multi-exponential models from DWI data. Each parameter was compared between TERTw and TERTm using the Mann-Whitney U test. Correlations between parameters derived from MRS and DWI were also evaluated. RESULTS: NAA/Cr and Cho/Cr were both higher for TERTw than for TERTm. The α of TERTw was smaller than that of TERTm, while the f of TERTw was higher than that of TERTm. NAA/Cr correlated negatively with α, but not with other DWI parameters. Cho/Cr did not show significant correlations with any DWI parameters. CONCLUSION: The combination of NAA/Cr and α may have merit in clinical situation to predict the TERT mutation status of IDH-wildtype diffuse astrocytic glioma without intense enhancement.

DOI： 10.1007/s00234-023-03177-y

記述言語：英語   掲載種別：研究論文（学術雑誌）  

We aimed to retrospectively determine the resection rate of fluid-attenuated inversion recovery (FLAIR) lesions to evaluate the clinical effects of supramaximal resection (SMR) on the survival of patients with glioblastoma (GBM). Thirty-three adults with newly diagnosed GBM who underwent gross total tumor resection were enrolled. The tumors were classified into cortical and deep-seated groups according to their contact with the cortical gray matter. Pre- and postoperative FLAIR and gadolinium-enhanced T1-weighted imaging tumor volumes were measured using a three-dimensional imaging volume analyzer, and the resection rate was calculated. To evaluate the association between SMR rate and outcome, we subdivided patients whose tumors were totally resected into the SMR and non-SMR groups by moving the threshold value of SMR in 10&#37; increments from 0&#37; and compared their overall survival (OS) change. An improvement in OS was observed when the threshold value of SMR was 30&#37; or more. In the cortical group (n = 23), SMR (n = 8) tended to prolong OS compared with gross total resection (GTR) (n = 15), with the median OS of 69.6 and 22.1 months, respectively (p = 0.0945). Contrastingly, in the deep-seated group (n = 10), SMR (n = 4) significantly shortened OS compared with GTR (n = 6), with median OS of 10.2 and 27.9 months, respectively (p = 0.0221). SMR could help prolong OS in patients with cortical GBM when 30&#37; or more volume reduction is achieved in FLAIR lesions, although the impact of SMR for deep-seated GBM must be validated in larger cohorts.

DOI： 10.2176/jns-nmc.2022-0351

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Gyrification patterns reflect early neurodevelopment and could be highly heritable. While some discrepant results have been reported, the most consistent finding was that patients with obsessive-compulsive disorder showed altered gyrification patterns in the orbitofrontal cortex. Nevertheless, no study has investigated the alterations in gyrification in unaffected first-degree relatives of patients with obsessive-compulsive disorder. We measured local gyrification by the FreeSurfer software in 23 unaffected first-degree relatives of patients with obsessive-compulsive disorder and 52 healthy control participants. We explored differences in the local gyrification index using vertex-wise whole-brain analysis and a region of interest-based approach in the medial and lateral orbitofrontal cortex. There was no significant difference in the local gyrification index between the 2 groups in the vertex-wise whole-brain analysis. Region of interest analyses showed that, compared with healthy controls, first-degree relatives showed significantly reduced local gyrification index in the left medial and lateral orbitofrontal cortex. A negative correlation was observed between the reduced local gyrification index in lateral orbitofrontal cortex and the subclinical anxiety scores of first-degree relatives. Our results showed that first-degree relatives of patients with obsessive-compulsive disorder had an altered local gyrification index in the orbitofrontal cortex. Especially, reduced local gyrification index in lateral orbitofrontal cortex associated with subclinical anxiety symptom could be a potential neurodevelopmental marker for the illness onset.

DOI： 10.1093/cercor/bhad170

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Previous studies have suggested that specific fronto-striatal circuits are associated with impaired motor response inhibition in patients with obsessive-compulsive disorder (OCD) and their relatives. However, no study has investigated the underlying resting-state network associated with motor response inhibition in the unaffected first-degree relatives of patients with OCD. We measured motor response inhibition using stop-signal task, and obtained resting-state fMRI in 23 first-degree relatives and 52 healthy control participants. We explored the group differences in the functional network from seed regions-of-interest (ROIs) associated with motor response inhibition abilities. We used the inferior frontal gyrus (IFG) and pre-supplementary motor area (pre-SMA) as seed-ROIs. A significant group difference was observed in functional connectivity between the pre-SMA and inferior parietal lobule. In the relative group, reduced functional connectivity between these areas was associated with a longer stop-signal reaction time. Additionally, relatives showed significantly greater functional connectivity between the IFG and SMA, precentral, and postcentral areas. Our results could provide new insights into the resting-state neural activity of the pre-SMA underlying impaired motor response inhibition of unaffected first-degree relatives. In addition, our results suggested that relatives have an altered connectivity of the sensorimotor region, similar to that of patients with OCD shown in previous literature.

DOI： 10.1093/cercor/bhad058

記述言語：英語  

We present a case of the T2-FLAIR mismatch sign in glioblastoma, isocitrate dehydrogenase (IDH)-wild type. The T2-FLAIR mismatch sign is known as a highly specific imaging finding of astrocytoma, IDH-mutant. Meanwhile, IDH-wildtype diffuse astrocytic gliomas with telomerase reverse transcriptase (TERT) promoter mutation in adults are defined as glioblastoma in the 2021 World Health Organization Classification of Tumors of the Central Nervous System, fifth edition (2021 WHO classification), which underscores the importance of molecular information in central nervous system tumors. This indicates even glioblastoma, IDH-wild type may be masquerading as lower-grade glioma in histology. The reasons for the discrepancy between tumors with less aggressive histology and poor prognosis caused by telomerase reverse transcriptase promoter mutation of IDH-wildtype diffuse glioma remain unclear. However, glioblastoma, IDH-wildtype should be considered as a potential differential diagnosis even in patients with the T2-FLAIR mismatch sign in diffuse gliomas.

DOI： 10.1177/20584601231184565

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: Accurate assessment of cerebral perfusion in moyamoya disease is necessary to determine the indication for treatment. We aimed to investigate the usefulness of dynamic PCASL using a variable TR scheme with optimized background suppression in the evaluation of cerebral perfusion in moyamoya disease. METHODS: We retrospectively analyzed the images of 24 patients (6 men and 18 women, mean age 31.4 ± 18.2 years) with moyamoya disease; each of whom was imaged with both dynamic PCASL using the variable-TR scheme and 123IMP SPECT with acetazolamide challenge. ASL dynamic data at 10 phases are acquired by changing the LD and PLD. The background suppression timing was optimized for each phase. CBF and ATT were measured with ASL, and CBF and CVR to an acetazolamide challenge were measured with SPECT. RESULTS: A significant moderate correlation was found between the CBF measured by dynamic PCASL and that by SPECT (r = 0.53, P < 0.001). The CBF measured by dynamic PCASL (52.5 ± 13.3 ml/100 mg/min) was significantly higher than that measured by SPECT (43.0 ± 12.6 ml/100 mg/min, P < 0.001). The ATT measured by dynamic PCASL showed a significant correlation with the CVR measured by SPECT (r = 0.44, P < 0.001). ATT was significantly longer in areas where the CVR was impaired (CVR < 18.4&#37;, ATT = 1812 ± 353 ms) than in areas where it was preserved (CVR > 18.4&#37;, ATT = 1301 ± 437 ms, P < 0.001). The ROC analysis showed a moderate accuracy (AUC = 0.807, sensitivity = 87.7&#37;, specificity = 70.4&#37;) when the cutoff value of ATT was set at 1518 ms. CONCLUSION: Dynamic PCASL using this scheme was found to be useful for assessing cerebral perfusion in moyamoya disease.

DOI： 10.1007/s00234-022-03095-5

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVES: To compare the delineation of mandibular cancer by 3D T1 turbo field echo with compressed SENSE (CS-3D-T1TFE) images and MDCT images, and to compare both sets of images with histopathological findings, as the gold standard, to validate the accuracy and clinical usefulness of CS-3D-T1TFE reconstruction. METHODS: Twenty-four patients with mandibular squamous cell carcinoma (SCC) who underwent MRI including CS-3D-T1TFE and MDCT examinations before surgery were retrospectively included. For both examinations, 0.5-mm-thick coronal plane images and 0.5-mm-thick plane images perpendicular and parallel to the dentition were constructed. Two radiologists rated bone invasion in three categories indexed by cortical bone, cancellous bone, and mandibular canal (MC), and inter-rater agreement was assessed by weighted kappa statistics. In 20 of the 24 patients who underwent surgery, the correlation of bone invasion with the histopathological evaluation by pathologists was assessed using Pearson's correlation coefficient. Soft-tissue invasion was assessed by diagnosing the presence of invasion into the mylohyoid muscle, gingivobuccal fold, and masticator space, and inter-rater agreement was assessed by kappa statistics. RESULTS: The interobserver agreement for bone invasion assessment was almost perfect with CS-3D-T1TFE and substantial with MDCT. The image evaluations by both observers agreed with the pathological evaluations in 15 of the 20 cases, showing high correlation (r > 0.8). CS-3D-T1TFE also showed higher inter-rater agreement than MDCT for all measures of soft-tissue invasion. CONCLUSIONS: CS-3D-T1TFE reconstructed images were clinically useful in accurately depicting the extent of mandibular cancer invasion and potentially solving the problem of lesion overestimation associated with conventional MRI. KEY POINTS: • Reconstructed CS-3D-T1TFE images were useful for the diagnosis of mandibular cancer. • CS-3D-T1TFE images showed higher inter-rater agreement than MDCT and high correlation with pathological findings. • CS-3D-T1TFE images may solve the problem of overestimation of the tumor extent, which has been associated with MRI in the past.

DOI： 10.1007/s00330-022-09075-w

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: We evaluated the usefulness of three-dimensional (3D) chemical exchange saturation transfer (CEST) imaging with compressed sensing and sensitivity encoding (CS-SENSE) for differentiating low-grade gliomas (LGGs) from high-grade gliomas (HGGs). METHODS: We evaluated 28 patients (mean age 51.0 ± 13.9 years, 13 males, 15 females) including 12 with LGGs and 16 with HGGs, all acquired using a 3 T magnetic resonance (MR) scanner. Nine slices were acquired for 3D CEST imaging, and one slice was acquired for two-dimensional (2D) CEST imaging. Two radiological technologists each drew a region of interest (ROI) surrounding the high-signal-intensity area(s) on the fluid-attenuated inversion recovery image of each patient. We compared the magnetization transfer ratio asymmetry (MTRasym) at 3.5 ppm in the tumors among the (i) single-slice 2D CEST imaging ("2D"), (ii) all tumor slices of the 3D CEST imaging (3Dall), and (iii) a representative tumor slice of 3D CEST imaging (maximum signal intensity [3Dmax]). The relationship between the MTRasym at 3.5 ppm values measured by these three methods and the Ki-67 labeling index (LI) of the tumors was assessed. Diagnostic performance was evaluated with a receiver operating characteristic analysis. The Ki-67LI and MTRasym at 3.5 ppm values were compared between the LGGs and HGGs. RESULTS: A moderate positive correlation between the MTRasym at 3.5 ppm and the Ki-67LI was observed with all three methods. All methods proved a significantly larger MTRasym at 3.5 ppm for the HGGs compared to the LGGs. All methods showed equivalent diagnostic performance. The signal intensity varied depending on the slice position in each case. CONCLUSIONS: The 3D CEST imaging provided the MTRasym at 3.5 ppm for each slice cross-section; its diagnostic performance was also equivalent to that of 2D CEST imaging.

DOI： 10.1016/j.ejrad.2022.110654

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: The mechanisms underlying accelerated long-term forgetting (ALF) in patients with epilepsy are still under investigation. We examined the contribution of hippocampal subfields and their morphology to long-term memory performance in patients with focal epilepsy. METHODS: We prospectively assessed long-term memory and performed magnetic resonance imaging in 80 patients with focal epilepsy (61 with temporal lobe epilepsy and 19 with extratemporal lobe epilepsy) and 30 healthy controls. The patients also underwent electroencephalography recording. Verbal and visuospatial memory was tested 30 s, 10 min, and 1 week after learning. We assessed the volumes of the whole hippocampus and seven subfields and deformation of the hippocampal shape. The contributions of the hippocampal volumes and shape deformation to long-term forgetting, controlling for confounding factors, including the presence of interictal epileptiform discharges, were assessed by multiple regression analyses. RESULTS: Patients with focal epilepsy had lower intelligence quotients and route recall scores at 10 min than controls. The focal epilepsy group had smaller volumes of both the right and left hippocampal tails than the control group, but there were no statistically significant group differences for the volumes of the whole hippocampus or other hippocampal subfields. Multiple regression analyses showed a significant association between the left CA1 volume and the 1-week story retention (β = 7.76; Bonferroni-corrected p = 0.044), but this was not found for the whole hippocampus or other subfield volumes. Hippocampal shape analyses revealed that atrophy of the superior-lateral, superior-central, and inferior-medial regions of the left hippocampus, corresponding to CA1 and CA2/3, was associated with the verbal retention rate. SIGNIFICANCE: Our results suggest that atrophy of the hippocampal CA1 region and its associated structures disrupts long-term memory consolidation in focal epilepsy. Neuronal cell loss in specific hippocampal subfields could be a key underlying cause of ALF in patients with epilepsy.

DOI： 10.1111/epi.17378

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To evaluate the accuracy of three-dimensional (3D) chemical exchange saturation transfer (CEST) imaging with a compressed sensing (CS) and sensitivity encoding (SENSE) technique (CS-SENSE) for full z-spectrum acquisition. METHODS: All images were acquired on 3-T magnetic resonance imaging (MRI) scanner. In the phantom study, we used the acidoCEST imaging. The phantoms were prepared in seven vials containing different concentrations of iopamidol mixed in phosphate-buffered solution with different pH values. The CEST ratios were calculated from the two CEST effects. We compared the CEST ratios obtained with three different 3D CEST imaging protocols (CS-SENSE factor 5, 7, 9) with those obtained with the 2D CEST imaging as a reference standard. In the clinical study, 21 intracranial tumor patients (mean 49.7 ± 17.2 years, 7 males and 14 females) were scanned. We compared the intratumor magnetization transfer ratio asymmetry (MTRasym) obtained with 3D CEST imaging with those obtained with 2D CEST imaging as a reference standard. RESULTS: A smaller CS-SENSE factor resulted in higher agreement and better correlations with the 2D CEST imaging in the phantom study (CS-SENSE 5; ICC = 0.977, R2 = 0.8943, P < 0.0001: CS-SENSE 7; ICC = 0.970, R2 = 0.9013, P < 0.0001: CS-SENSE 9; ICC = 0.934, R2 = 0.8156 P < 0.0001). In the brain tumors, the means and percentile values of MTRasym at 2.0 and 3.5 ppm showed high linear correlations (R2 = 0.7325-0.8328, P < 0.0001) and high ICCs (0.859-0.907), which enabled successful multi-slice CEST imaging. CONCLUSIONS: The 3D CEST imaging with CS-SENSE provided equivalent contrast to 2D CEST imaging; moreover, a z-spectrum with a wide scan range could be obtained.

DOI： 10.1016/j.mri.2022.05.014

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

It is often difficult to distinguish infectious disease of the central nervous system from a wide variety of non-infectious diseases, as neurosurgeons have few opportunities to treat them. Differentiation of infectious diseases from neoplastic diseases is often challenging. Since it often takes time to eliminate infectious diseases, it is necessary to utilize all the obtained medical information to make a proper diagnosis to avoid missing the appropriate chance of surgical treatment. In this paper, we describe tips for and pitfalls of accurately distinguishing such diseases, including brain abscess versus glioblastoma, meningitis versus dural lesions, and infection versus lymphoproliferative disorders in immunocompromised patients. In these cases, it is difficult to make a decision based only on the examination and imaging findings on admission, and it is important to make a diagnosis based on medical history and patient background.

DOI： 10.11477/mf.1436204658

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Amide proton transfer-weighted (APTw) MR imaging shows promise as a biomarker of brain tumor status. Currently used APTw MRI pulse sequences and protocols vary substantially among different institutes, and there are no agreed-on standards in the imaging community. Therefore, the results acquired from different research centers are difficult to compare, which hampers uniform clinical application and interpretation. This paper reviews current clinical APTw imaging approaches and provides a rationale for optimized APTw brain tumor imaging at 3 T, including specific recommendations for pulse sequences, acquisition protocols, and data processing methods. We expect that these consensus recommendations will become the first broadly accepted guidelines for APTw imaging of brain tumors on 3 T MRI systems from different vendors. This will allow more medical centers to use the same or comparable APTw MRI techniques for the detection, characterization, and monitoring of brain tumors, enabling multi-center trials in larger patient cohorts and, ultimately, routine clinical use.

DOI： 10.1002/mrm.29241

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Background It is gradually becoming clear that obsessive-compulsive disorder (OCD) patients have aberrant resting-state large-scale intrinsic networks of cingulo-opercular salience (SN), default mode (DMN), and front-parietal network (FPN). However, it remains unknown whether unaffected first-degree relatives of OCD patients have these alterations as a vulnerability marker to the disorder. Methods We performed resting-state functional magnetic resonance imaging (rsfMRI) scans of 47 medication-free OCD patients, 21 unaffected healthy first-degree relatives of OCD patients, and 62 healthy control (HC) participants. We explored differences between the three groups in the functional connectivity from SN (seeds: anterior-insula (AI) and dorsal anterior cingulate cortex (dACC)), DMN (seeds: medial prefrontal cortex (MPFC) and posterior parietal cortex (PCC)), and FPN (seeds: dorsolateral prefrontal cortex (DLPFC)). Results Compared to HC, both OCD patients and first-degree relatives showed significantly greater functional connectivity between AI and PCC and between DLPFC and the thalamus. Compared to first-degree relatives and HC, OCD patients showed reduced functional connectivity between PCC and DLPFC, and this altered functional connectivity was negatively correlated with anxiety and depressive symptom within OCD group. Conclusions OCD patients and unaffected first-degree relatives of OCD patients showed overlapping alterations in resting state functional connectivity between the regions of SN and DMN and between DLPFC and the thalamus. Our results suggested that alterations between large-scale intrinsic networks and within the dorsal cognitive cortico-striato-thalamo-cortical (CSTC) circuit could represent endophenotype markers of OCD.

DOI： 10.1016/j.pnpbp.2022.110516

記述言語：英語   掲載種別：研究論文（学術雑誌）  

This study aimed to determine whether quantitative relaxometry using synthetic magnetic resonance imaging (SyMRI) could differentiate between two diffuse glioma groups with isocitrate dehydrogenase (IDH)-mutant tumors, achieving an increased sensitivity compared to the qualitative T2-fluid-attenuated inversion recovery (FLAIR) mismatch sign. Between May 2019 and May 2020, thirteen patients with IDH-mutant diffuse gliomas, including seven with astrocytomas and six with oligodendrogliomas, were evaluated. Five neuroradiologists independently evaluated the presence of the qualitative T2-FLAIR mismatch sign. Interrater agreement on the presence of the T2-FLAIR mismatch sign was calculated using the Fleiss kappa coefficient. SyMRI parameters (T1 and T2 relaxation times and proton density) were measured in the gliomas and compared by the Mann-Whitney U test. Receiver operating characteristic curve analysis was used to evaluate the diagnostic performance. The sensitivity, specificity, and kappa coefficient were 57.1&#37;, 100&#37;, and 0.60, respectively, for the qualitative T2-FLAIR mismatch sign. The two types of diffuse gliomas could be differentiated using a cutoff value of 178 ms for the T2 relaxation time parameter with 100&#37; sensitivity, specificity, accuracy, and positive and negative predictive values, with an area under the curve (AUC) of 1.00. Quantitative relaxometry using SyMRI could differentiate astrocytomas from oligodendrogliomas, achieving an increased sensitivity and objectivity compared to the qualitative T2-FLAIR mismatch sign.

DOI： 10.1038/s41598-022-13036-0

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVES: To develop an automated model to detect brain metastases using a convolutional neural network (CNN) and volume isotropic simultaneous interleaved bright-blood and black-blood examination (VISIBLE) and to compare its diagnostic performance with the observer test. METHODS: This retrospective study included patients with clinical suspicion of brain metastases imaged with VISIBLE from March 2016 to July 2019 to create a model. Images with and without blood vessel suppression were used for training an existing CNN (DeepMedic). Diagnostic performance was evaluated using sensitivity and false-positive results per case (FPs/case). We compared the diagnostic performance of the CNN model with that of the twelve radiologists. RESULTS: Fifty patients (30 males and 20 females; age range 29-86 years; mean 63.3 ± 12.8 years; a total of 165 metastases) who were clinically diagnosed with brain metastasis on follow-up were used for the training. The sensitivity of our model was 91.7&#37;, which was higher than that of the observer test (mean ± standard deviation; 88.7 ± 3.7&#37;). The number of FPs/case in our model was 1.5, which was greater than that by the observer test (0.17 ± 0.09). CONCLUSIONS: Compared to radiologists, our model created by VISIBLE and CNN to diagnose brain metastases showed higher sensitivity. The number of FPs/case by our model was greater than that by the observer test of radiologists; however, it was less than that in most of the previous studies with deep learning. KEY POINTS: • Our convolutional neural network based on bright-blood and black-blood examination to diagnose brain metastases showed a higher sensitivity than that by the observer test. • The number of false-positives/case by our model was greater than that by the previous observer test; however, it was less than those from most previous studies. • In our model, false-positives were found in the vessels, choroid plexus, and image noise or unknown causes.

DOI： 10.1007/s00330-021-08427-2

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: To determine whether the γ distribution (GD) model of diffusion MRI is useful in the evaluation of the isocitrate dehydrogenase (IDH) mutation status of glioblastomas. METHODS: 12 patients with IDH-mutant glioblastomas and 54 patients with IDH-wildtype glioblastomas were imaged with diffusion-weighted imaging using 13 b-values from 0 to 1000 s/mm2. The shape parameter (κ) and scale parameter (θ) were obtained with the GD model. Fractions of three different areas under the probability density function curve (f1, f2, f3) were defined as follows: f1, diffusion coefficient (D) < 1.0×10-3 mm2/s; f2, D > 1.0×10-3 and <3.0×10-3 mm2/s; f3, D > 3.0 × 10-3 mm2/s. The GD model-derived parameters measured in gadolinium-enhancing lesions were compared between the IDH-mutant and IDH-wildtype groups. Receiver operating curve analyses were performed to assess the parameters' diagnostic performances. RESULTS: The IDH-mutant group's f1 (0.474  ±  0.143) was significantly larger than the IDH-wildtype group's (0.347  ±  0.122, p = 0.0024). The IDH-mutant group's f2 (0.417  ±  0.131) was significantly smaller than the IDH-wildtype group's (0.504  ±  0.126, p = 0.036). The IDH-mutant group's f3 (0.109  ±  0.060) was significantly smaller than the IDH-wildtype group's (0.149  ±  0.063, p = 0.0466). The f1 showed the best diagnostic performance among the GD model-derived parameters with the area under the curve value of 0.753. CONCLUSION: The GD model could well describe the pathological features of IDH-mutant and IDH-wildtype glioblastomas, and was useful in the differentiation of these tumors. ADVANCES IN KNOWLEDGE: Diffusion MRI based on the γ distribution model could well describe the pathological features of IDH-mutant and IDH-wildtype glioblastomas, and its use enabled the significant differentiation of these tumors. The γ distribution model may contribute to the non-invasive identification of the IDH mutation status based on histological viewpoint.

DOI： 10.1259/bjr.20210392

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Although preliminary neuroimaging research suggests that patients with hoarding disorder (HD) show widespread abnormal task-related activity in the brain, there has been no research on alterations in the white matter tracts in these patients. The aim of this study was to investigate the characteristics of the major white matter tracts in patients with HD. Tract-based spatial statistics were used to search for white matter tract abnormalities throughout the brain in 25 patients with HD and 36 healthy controls. Post hoc analysis of regions of interest was performed to detect correlations with clinical features. Compared with the controls, patients with HD showed decreased fractional anisotropy and increased radial diffusivity in anatomically widespread white matter tracts. Post hoc analysis of regions of interest revealed a significant negative correlation between the severity of hoarding symptoms and fractional anisotropy in the left anterior limb of the internal capsule and a positive correlation between the severity of these symptoms and radial diffusivity in the right anterior thalamic radiation. Patients with HD showed a broad range of alterations in the frontal white matter tracts, including the frontothalamic circuit, frontoparietal network, and frontolimbic pathway. The findings of this study indicate associations between frontal white matter abnormalities related to the severity of hoarding symptoms in HD and the cortical regions involved in cognitive dysfunction. The insights provided would be useful for understanding the neurobiological basis of HD.

DOI： 10.1016/j.jpsychires.2022.01.031

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Controversies exist regarding the aggressive recurrence of glioblastoma after bevacizumab treatment. We analyzed the clinical impact of bevacizumab approval in Japan by evaluating the clinical course and relapse pattern in patients with glioblastoma. METHODS: We included 100 patients with IDH-wild-type glioblastoma from September 2006 to February 2018 in our institution. The patients were classified into the pre-bevacizumab (n = 51) and post-bevacizumab (n = 49) groups. Overall, progression-free, deterioration-free, and postprogression survivals were compared. We analyzed the relapse pattern of 72 patients, whose radiographic progressions were evaluated. RESULTS: Significant improvement in progression-free (pre-bevacizumab, 7.5 months; post-bevacizumab, 9.9 months; P = 0.0153) and deterioration-free (pre-bevacizumab, 8.5 months; post-bevacizumab, 13.8 months; P = 0.0046) survivals was seen. These survival prolongations were strongly correlated (r: 0.91, P < 0.0001). The nonenhancing tumor pattern was novel in the post-bevacizumab era (5 of 33). The presence of a nonenhancing tumor did not indicate poor postprogression survival (hazard ratio: 0.82 [0.26-2.62], P = 0.7377). The rate of early focal recurrence was significantly lower (P = 0.0155) in the post-bevacizumab (4 of 33) than in the pre-bevacizumab (18 of 39) era. There was a significant decrease in early focal recurrence after approval of bevacizumab in patients with unresectable tumors (P = 0.0110). The treatment era was significantly correlated with a decreased rate of early focal recurrence (P = 0.0021, univariate analysis; P = 0.0144, multivariate analysis). CONCLUSIONS: Approval of first-line bevacizumab in Japan for unresectable tumors may prevent early progression and clinical deterioration of glioblastoma without worsening the clinical course after relapse.

DOI： 10.1016/j.wneu.2021.12.075

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Recent evidence suggests that presupplementary motor area (pre-SMA) and inferior frontal gyrus (IFG) play an important role in response inhibition. However, no study has investigated the relationship between these brain networks at resting-state and response inhibition in obsessive-compulsive disorder (OCD). We performed resting-state functional magnetic resonance imaging scans and then measured the response inhibition of 41 medication-free OCD patients and 49 healthy control (HC) participants by using the stop-signal task outside the scanner. We explored the differences between OCD and HC groups in the functional connectivity of pre-SMA and IFG associated with the ability of motor response inhibition. OCD patients showed a longer stop-signal reaction time (SSRT). Compared to HC, OCD patients exhibit different associations between the ability of motor response inhibition and the functional connectivity between pre-SMA and IFG, inferior parietal lobule, dorsal anterior cingulate cortex, insula, and anterior prefrontal cortex. Additional analysis to investigate the functional connectivity difference from the seed ROIs to the whole brain voxels revealed that, compared to HC, OCD exhibited greater functional connectivity between pre-SMA and IFG. Also, this functional connectivity was positively correlated with the SSRT score. These results provide additional insight into the characteristics of the resting-state functional connectivity of the regions belonging to the cortico-striato-thalamo-cortical circuit and the cingulo-opercular salience network, underlying the impaired motor response inhibition of OCD. In particular, we emphasize the importance of altered functional connectivity between pre-SMA and IFG for the pathophysiology of motor response inhibition in OCD.

DOI： 10.1002/hbm.25699

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVES: To compare the gamma distribution (GD), intravoxel incoherent motion (IVIM), and monoexponential (ME) models in terms of their goodness-of-fit, correlations among the parameters, and the effectiveness in the differential diagnosis of various orofacial lesions. METHODS: A total of 85 patients underwent turbo spin-echo diffusion-weighted imaging with six b-values. The goodness-of-fit of three models was assessed using Akaike Information Criterion. We analysed the correlations and compared the effectiveness in the differential diagnosis among the parameters of GD model (κ, shape parameter; θ, scale parameter; fractions of diffusion: ƒ1, cellular component; ƒ2, extracellular diffusion; ƒ3, perfusion component), IVIM model (D, true diffusion coefficient; D*, pseudodiffusion coefficient; f, perfusion fraction), and ME model (apparent diffusion coefficient, ADC). RESULTS: The GD and IVIM models showed a better goodness-of-fit than the ME model (p < 0.05). ƒ1 had strong negative correlations with D and ADC (ρ = -0.901 and -0.937, respectively), while ƒ3 had a moderate positive correlation with f (ρ = 0.661). Malignant entity presented significantly higher ƒ1 and lower D and ADC than benign entity (p < 0.0001). Malignant lymphoma had significantly higher ƒ1 in comparison to squamous cell carcinoma (p = 0.0007) and granulation (p = 0.0075). The trend in ƒ1 was opposite to the trend in D. Malignant lymphoma had significant lower ƒ3 than squamous cell carcinoma (p = 0.005) or granulation (p = 0.0075). CONCLUSIONS: The strong correlations were found between the GD- and IVIM-derived parameters. Furthermore, the GD model's parameters were useful for characterising the pathological structure in orofacial lesions.

DOI： 10.1259/dmfr.20200609

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: This study investigated the optimal labeling position and gradient moment for 4D-MR angiography based on superselective pseudo-continuous arterial spin labeling combined with CENTRA-keyhole and view-sharing (4D-S-PACK) for vessel-selective flow visualization of the internal carotid artery (ICA) and vertebrobasilar artery (VBA) systems. METHODS: Seven healthy volunteers were scanned with a 3.0 T MR scanner. To visualize the ICA system, the labeling focus was placed in the right ICA at 55, 75 and 95 mm below the imaging slab. To visualize the VBA system, the labeling focus was placed in the basilar artery (BA), upper vertebral artery (VA upper), and lower vertebral artery (VA lower). Two sizes of labeling focus were created using gradient moments of 0.5 and 0.75 mT/m ms. The contrast-to-noise ratio (CNR) was measured in the middle cerebral artery (MCA) and posterior cerebral artery (PCA) branches. RESULTS: CNRs increased as the distance between the center of the imaging slab and the labeling position decreased in all MCA segments. CNRs obtained with VA lower tended to be higher than those obtained with BA and VA upper in all PCA segments. Selective vessel visualization was achieved with the gradient moment of 0.75 mT/m ms for the ICA and VBA system. CONCLUSION: The optimal 4D-S-PACK gradient moment was found to be 0.75 mT/m ms for the ICA and VBA systems. When visualizing the ICA system, the labeling position should be placed as close as possible to the imaging slab. When visualizing the VBA system, the labeling position should be placed at VA lower .

DOI： 10.1016/j.mri.2021.10.040

記述言語：英語  

Alveolar soft part sarcoma is a rare soft tissue neoplasm that accounts for approximately 1&#37; of all sarcomas and is usually identified in the extremities in adults. The occurrence of alveolar soft part sarcoma in the orbit is extremely rare, estimated at approximately 5&#37; - 15&#37; among all cases of alveolar soft part sarcoma . Here, we present a case of 29-year-old woman with orbital alveolar soft part sarcoma. We describe the magnetic resonance and F-18 2-fluoro-2-deoxy-D-glucose-position emission tomography/computed tomography findings of this case. This young woman had a spindle-shaped mass. A higher signal compared to the extraocular muscle on T1-weighted images, numerous flow voids on T2-weighted images, and intense enhancement could be key findings of this disease.

DOI： 10.1016/j.radcr.2021.09.005

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: Although we have shown the clinical benefit of bevacizumab (BEV) in the treatment of unresectable newly diagnosed glioblastomas (nd-GBM), the relationship between early radiographic response and survival outcome remains unclear. We performed a volumetric study of early radiographic responses in nd-GBM treated with BEV. METHODS: Twenty-two patients with unresectable nd-GBM treated with BEV during concurrent temozolomide radiotherapy were analyzed. An experienced neuroradiologist interpreted early responses on fluid-attenuated inversion recovery (FLAIR) and gadolinium-enhanced T1-weighted images (GdT1WI). Volumetric changes were evaluated using diffusion-weighted imaging (DWI) and GdT1WI according to the Response Assessment in Neuro-Oncology (RANO) criteria. The results were categorized into improved (complete response [CR] or partial response [PR]) or non-improved (stable disease [SD] or progressive disease [PD]) groups; outcomes were compared using Kaplan-Meier analysis. RESULTS: The volumetric GdT1WI improvement was a significant predictive factor for overall survival (OS) prolongation (p = 0.0093, median OS: 24.7 vs. 13.6 months); however, FLAIR and DWI images were not predictive. The threshold for the neuroradiologist's interpretation of improvement in GdT1WI was nearly 20&#37; of volume reduction, which was lesser than 50&#37;, the definition of PR applied in the RANO criteria. However, even less stringent neuroradiologist interpretation could successfully predict OS prolongation (improved vs. non-improved: p = 0.0067, median OS: 17.6 vs. 8.3 months). Significant impact of OS on the early response in volumetric GdT1WI was observed within the cut-off range of 20-50&#37; (20&#37;, p = 0.0315; 30&#37;, p = 0.087; 40&#37;, p = 0.0456). CONCLUSIONS: Early response during BEV-containing chemoradiation can be a predictive indicator of patient outcome in unresectable nd-GBM.

DOI： 10.1007/s11060-021-03812-9

記述言語：英語  

Craniopharyngiomas are benign neoplasms with two histological subtypes: adamantinomatous and papillary. Papillary craniopharyngiomas are rare in children, and those with a pituitary abscess within are even rarer. Herein, we present the case of a 14-year-old boy with a papillary craniopharyngioma and a coexisting intratumoral abscess, who was hospitalized for persistent pyrexia, polyuria, and polydipsia. The absence of calcification on computed tomography, high signal intensity inside the tumor on diffusion-weighted imaging, and clinical findings such as fever, a high inflammatory response, and meningitis, as well as short-term morphological changes on imaging, could aid in diagnosis.

DOI： 10.1177/20584601211030661

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVES: To examine the utility of FDG-PET/MRI in patients with epilepsy by comparing the diagnostic accuracy of PET/MRI and PET/CT in epileptogenic zone (EZ) detection. METHODS: This prospective study included 31 patients (17 males, 14 females) who underwent surgical resection for EZ. All patients were first scanned using FDG-PET/CT followed immediately with FDG-PET/MRI. Two series of PET plus standalone MR images were interpreted independently by five board-certified radiologists. A 4-point visual score was used to assess image quality. Sensitivities and visual scores from both PETs and standalone MRI were compared using the McNemar test with Bonferroni correction and Dunn's multiple comparisons test. RESULTS: The EZs were confirmed histopathologically via resection as hippocampal sclerosis (n = 11, 35.5&#37;), gliosis (n = 8, 25.8&#37;), focal cortical dysplasia (n = 6, 19.4&#37;), and brain tumours (n = 6, 19.4&#37;) including cavernous haemangioma (n = 3), dysembryoplastic neuroepithelial tumour (n = 1), ganglioglioma (n = 1), and polymorphous low-grade neuroepithelial tumour of the young (n = 1). The sensitivity of FDG-PET/MRI was significantly higher than that of FDG-PET/CT and standalone MRI (FDG-PET/MRI vs. FDG-PET/CT vs. standalone MRI; 77.4-90.3&#37; vs. 58.1-64.5&#37; vs. 45.2-80.6&#37;, p < 0.0001, respectively). The visual scores derived from FDG-PET/MRI were significantly higher than those of FDG-PET/CT, as well as standalone MRI (2.8 ± 1.2 vs. 2.0 ± 1.1 vs. 2.1 ± 1.2, p < 0.0001, respectively). Compared to FDG-PET/CT, FDG-PET/MRI increased the visual score (51.9&#37;, increased visual scores of 2 and 3). CONCLUSIONS: The diagnostic accuracy for the EZ detection in focal epilepsy could be higher in FDG-PET/MRI than in FDG-PET/CT. KEY POINTS: • Sensitivity of FDG-PET/MRI was significantly higher than that of FDG-PET/CT and standalone MRI (FDG-PET/MRI vs. FDG-PET/CT vs. standalone MRI; 77.4-90.3&#37; vs. 58.1-64.5&#37; vs. 45.2-80.6&#37;, p < 0.0001, respectively). • Visual scores derived from FDG-PET/MRI were significantly higher than those of FDG-PET/CT and standalone MRI (2.8 ± 1.2 vs. 2.0 ± 1.1 vs. 2.1 ± 1.2, p < 0.0001, respectively). • Compared to FDG-PET/CT, FDG-PET/MRI increased the visual score (51.9&#37;, increased visual scores of 2 and 3).

DOI： 10.1007/s00330-020-07389-1

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: Accumulating evidence from recent molecular diagnostic studies has indicated the prognostic significance of various genetic markers for patients with glioblastoma (GBM). To evaluate the impact of such genetic markers on prognosis, we retrospectively analyzed the outcomes of patients with IDH-wildtype GBM in our institution. In addition, to assess the impact of bevacizumab (BEV) treatment, we compared overall survival (OS) between the pre- and post-BEV eras. METHODS: We analyzed the data of 100 adult patients (over 18 years old) with IDH-wildtype GBM from our database between February 2006 and October 2018. Genetic markers, such as MGMT methylation status, EGFR amplification, CDKN2A homozygous deletion, and clinical factors were analyzed by evaluating the patients' OS. RESULTS: CDKN2A homozygous deletion showed no significant impact on OS in patients with methylated MGMT status (p = 0.5268), whereas among patients with unmethylated MGMT status, there was a significant difference in OS between patients with and without CDKN2A homozygous deletion (median OS: 14.7 and 16.9 months, respectively, p = 0.0129). This difference was more evident in the pre-BEV era (median OS: 10.1 and 15.6 months, respectively, p = 0.0351) but has become nonsignificant in the post-BEV era (median OS: 16.0 and 16.9 months, respectively, p = 0.1010) due to OS improvement in patients with CDKN2A homozygous deletion. However, these findings could not be validated in The Cancer Genome Atlas cohort. CONCLUSIONS: MGMT and CDKN2A status subdivided our cohort into three race-specific groups with different prognoses. Our findings indicate that BEV approval in Japan led to OS improvement exclusively for patients with concurrent unmethylated MGMT status and CDKN2A homozygous deletion.

DOI： 10.1002/cam4.3860

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVES: This study evaluated the correlation among the diffusion-derived parameters obtained by monoexponential (ME), intravoxel incoherent motion (IVIM) and γ distribution (GD) models and compared these parameters among representative orofacial tumours. METHODS: Ninety-two patients who underwent 1.5 T MRI including diffusion-weighted imaging were included. The shape parameter (κ), scale parameter (θ), ratio of the intracellular diffusion (ƒ1), extracellular diffusion (ƒ2) and perfusion (ƒ3) were obtained by the GD model; the true diffusion coefficient (D) and perfusion fraction (f) were obtained by the IVIM model; and the apparent diffusion coefficient (ADC) was obtained by the ME model. RESULTS: ƒ1 had a strongly negative correlation with the ADC (ρ = -0.993) and D (ρ = -0.926). A strong positive correlation between f and ƒ3 (ρ = 0.709) was found. Malignant lymphoma (ML) had the highest ƒ1, followed by squamous cell carcinoma (SCC), malignant salivary gland tumours, pleomorphic adenoma (Pleo) and angioma. Both the IVIM and GD models suggested the highest perfusion in angioma and the lowest perfusion in ML. The GD model demonstrated a high extracellular component in Pleo and revealed that the T4a+T4b SCC group had a lower ƒ2 than the T2+T3 SCC group, and poor to moderately differentiated SCC had a higher ƒ1 than highly differentiated SCC. CONCLUSIONS: Given the correlation among the diffusion-derived parameters, the GD model might be a good alternative to the IVIM model. Furthermore, the GD model's parameters were useful for characterizing the pathological structure.

DOI： 10.1259/dmfr.20200252

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: Multi-spin echo acquisition cine imaging (MUSACI) is a method used for cerebrospinal fluid (CSF) dynamics imaging based on the proton phase dispersion and flow void using 3D multi-spin echo imaging. In a previous study, the refocusing flip angle of MUSACI was set at a constant 80°. We conducted the present study to investigate the preservation the CSF signal intensity even in a long echo train and improve the ability to visualize CSF movement by modifying the refocusing flip angle in MUSACI. METHODS: The MUSACI images were acquired in 10 healthy volunteers (7 men and 3 women; age range 24-44 years; mean age 29.4 ± 6.2 years) with a 3.0 Tesla MR scanner. Five refocusing flip angle sets were applied: constant 30°, constant 50°, constant 80°, pseudo-steady state (PSS) 50°-70°-100° (PSS50°), and PSS80°-100°-130° (PSS80°). In all sequences, the in-plane spatial resolution was 0.58 × 0.58 mm2, and the CSF movement for one heartbeat was drawn at 80-msec intervals. The signal intensity (SI) of CSF in the lateral ventricle, the foramen of Monro, the third ventricle, the fourth ventricle, and the pons was measured on MUSACI. Pearson's correlation coefficient was calculated between the CSF SI and effective echo time (TE; TEeff) in the lateral ventricle. RESULTS: Both antegrade and retrograde CSF movements on the midsagittal MUSACI images and the retrograde CSF movement in the foramen of Monro was observed in all sequences with the constant flip angles. A strong reverse correlation between the CSF SI in the lateral ventricle and TEeff values was observed with constant 30° (r = -0.96, p < 0.01), constant 50° (r = -0.97, p < 0.01) and constant 80° (r = -0.88, p < 0.01). A weak positive correlation was observed with PSS50° (r = 0.28, p = 0.43), and a moderate reverse correlation was observed at PSS80° (r = -0.60, p = 0.07). The SI values of the foramen of Monro, the third ventricle, and the fourth ventricle were significantly lower than that of the lateral ventricle, and those values were higher than that of the pons in both the constant 80° sequence and the PSS 50° sequence. CONCLUSION: PSS50° could be the optimal flip angle scheme for MUSACI, because the SI changes due to CSF movement and the SI preservation due to a long echo train were large due to the use of the refocusing flip angle method.

DOI： 10.1016/j.mri.2020.11.013

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Since patients with schizophrenia (SZ) and bipolar disorder (BD) share many biological features, detecting biomarkers that differentiate SZ and BD patients is crucial for optimized treatments. High-resolution magnetic resonance imaging (MRI) is suitable for detecting subtle brain structural differences in patients with psychiatric disorders. In the present study, we adopted a neuroanatomically defined and manually delineated region of interest (ROI) method to evaluate the amygdalae, hippocampi, Heschl's gyrus (HG), and planum temporale (PT), because these regions are crucial in the development of SZ and BD. ROI volumes were measured using high resolution MRI in 31 healthy subjects (HS), 23 SZ patients, and 21 BD patients. Right hippocampal volumes differed significantly among groups (HS > BD > SZ), whereas left hippocampal volumes were lower in SZ patients than in HS and BD patients (HS = BD > SZ). Volumes of the amygdalae, HG, and PT did not differ among the three groups. For clinical correlations, there were no significant associations between ROI volumes and demographics/clinical symptoms. Our study revealed significant lower hippocampal volume in patients with SZ and BD, and we suggest that the right hippocampal volume is a potential biomarker for differentiation between SZ and BD.

DOI： 10.3390/jpm11020121

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Cortical lesions (CLs) have a low prevalence and are associated with physical disabilities in Japanese patients with multiple sclerosis (MS). However, the contribution of CLs to cognitive impairment remains unclear in Asian MS. Sixty-one prospectively enrolled MS patients underwent three-dimensional double inversion recovery MR imaging, the Brief Repeatable Battery of Neuropsychological Tests (BRB-N), the Apathy Scale (AS), the Fatigue Questionnaire (FQ), and the Hospital Anxiety and Depression Scale (HADS) within a 1-week period. The cognitive impairment index (CII) score was calculated to measure patients’ overall cognitive impairment. MS patients with CLs had poorer scores than those without CLs in most BRB-N tests, but scored comparably in the FQ, AS, and HADS. The number of CLs correlated negatively with all BRB-N test scores and positively with total CII scores. Leukocortical lesions were more extensively associated with cognitive dysfunction in various domains than intracortical lesions. Stepwise multiple regression analysis revealed that potential confounding factors for the highest quartile of CII score were the number of CLs (odds ratio 2.38, p = 0.0070) and the Expanded Disability Severity Scale score (odds ratio 2.13, p = 0.0003). Our results demonstrate that the presence and number of CLs are robustly associated with cognitive dysfunction in Asian MS patients.

DOI： 10.1038/s41598-020-61012-3

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVES: To evaluate the usefulness of 4D-MR angiography based on super-selective pseudo-continuous ASL combined with keyhole and view-sharing (4D-S-PACK) for vessel-selective visualization and to examine the ability of this technique to visualize brain arteriovenous malformations (AVMs). METHODS: In this retrospective study, 15 patients (ten men and five women, mean age 44.0 ± 16.9 years) with brain AVMs were enrolled. All patients were imaged with 4D-PACK (non-selective), 4D-S-PACK, and digital subtraction angiography (DSA). Observers evaluated vessel selectivity, identification of feeding arteries and venous drainage patterns, visualization scores, and contrast-to-noise ratio (CNR) for each AVM component. Measurements were compared between the MR methods. RESULTS: Vessel selectivity was graded 4 in 43/45 (95.6&#37;, observer 1) and 42/45 (93.3&#37;, observer 2) territories and graded 3 in two (observer 1) and three (observer 2) territories. The sensitivity and specificity for identification of feeding arteries for both observers was 88.9&#37; and 100&#37; on 4D-PACK, and 100&#37; and 100&#37; on 4D-S-PACK, respectively. For venous drainage, the sensitivity and specificity was 100&#37; on both methods for observer 1. The sensitivity and specificity for observer 2 was 94.4&#37; and 83.3&#37; on 4D-PACK, and 94.4&#37; and 91.7&#37; on 4D-S-PACK, respectively. The CNRs at the timepoint of 1600 ms were slightly lower in 4D-S-PACK than in 4D-PACK for all AVM components (Feeding artery, p = .02; nidus, p = .001; and draining artery, p = .02). The visualization scores for both observers were not significantly different between 4D-PACK and 4D-S-PACK for all components. CONCLUSIONS: 4D-S-PACK could be a useful non-invasive clinical tool for assessing hemodynamics in brain AVMs. KEY POINTS: • The 4D-MR angiography based on super-selective pseudo-continuous arterial spin labeling combined with CENTRA-keyhole and view-sharing (4D-S-PACK) enabled excellent vessel selectivity. • The 4D-S-PACK enabled the perfect identification of feeding arteries of brain arteriovenous malformation (AVM). • 4D-S-PACK could be a non-invasive clinical tool for assessing hemodynamics in brain AVMs.

DOI： 10.1007/s00330-020-07057-4

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: Four-dimensional magnetic resonance angiography (4D-MRA) based on super-selective pseudo-continuous arterial spin labeling, combined with Keyhole and View-sharing (4D-S-PACK) was introduced for scan-accelerated vessel-selective 4D-MRA. Label selectivity and visualization effectiveness were assessed. METHODS: Nine healthy volunteers were included in the study. The label selectivity for the imaging of internal carotid artery (ICA) and external carotid artery (ECA) circulation was assessed qualitatively. The contrast-to-noise ratio (CNR) in 4D-S-PACK was measured in four middle cerebral artery (MCA) and superficial temporal artery (STA) segments and compared with that in contrast-inherent inflow-enhanced multi-phase angiography combined with the vessel-selective arterial spin labeling technique (CINEMA-select). Vessel-selective arterial visualization in 4D-S-PACK was assessed qualitatively in a patient with dural arteriovenous fistula and compared with digital subtraction angiography (DSA) and non-vessel selective 4D-PACK. RESULTS: 4D-S-PACK vessel selectivity was judged to be at a clinically acceptable level in all cases except one ECA-targeted label. The CNR was significantly higher using 4D-S-PACK compared with CINEMA-select in MCA and STA peripheral segments (p < 0.001). In patient examination, territorial flow visualization in feeding artery and draining vein circulation on 4D-S-PACK were comparable with that on DSA and the identification of such responsible vessels was easier on 4D-S-PACK than on 4D-PACK. CONCLUSION: 4D-S-PACK showed high vessel-selectivity and higher visualization effectiveness compared with CINEMA-select. One clinical case was performed and ICA and ECA territorial flow was successfully visualized separately, suggesting clinical usefulness.

DOI： 10.1016/j.mri.2020.07.013

記述言語：英語   掲載種別：研究論文（学術雑誌）  

There may be different neural bases between subjects with epilepsy only (EP) and interictal chronic epilepsy psychosis (EPS). However, there have been few structural MRI studies of EPS. The current study was conducted to investigate the neural substrate of EPS. T1-weighted images were analyzed in 14 patients with EPS and 14 strictly-matched patients with EP. We conducted volume comparison in the whole brain using voxel-based morphometry (VBM). The VBM method revealed that EPS patients exhibited significantly reduced gray matter volumes in the left postcentral gyrus and the left supra marginal gyrus compared with EP patients (adjusted p = 0.029, FDR corrected q; k = 319 voxels). For clinical correlations, there were no significant associations between psychotic symptoms and gray matter volumes in the left postcentral gyrus and the left supra marginal gyrus. VBM analysis revealed that reduced gray matter volumes in the left postcentral gyrus and the left supra marginal gyrus may be crucial regions for EPS.

DOI： 10.1007/s11682-019-00044-4

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Although magnetic resonance imaging (MRI) provides excellent soft-tissue contrast, long acquisition times are major disadvantages. PURPOSE: To evaluate the usefulness of compressed sensing (CS) for contrast-enhanced oral and maxillofacial MRI by comparing the 3D T1 turbo field echo with compressed SENSE (CS-3D-T1TFE) sequence with the multi-slice spin echo (MS-SE) sequence as the reference standard. MATERIAL AND METHODS: Thirty patients with orofacial lesions participated in this study. The scan times for MS-SE and CS-3D-T1TFE were 5 min 56 s and 1 min 43 s, respectively. The signal-to-noise ratio (SNR) was calculated for quantitative analysis and seven parameters (degree of lesion conspicuity, motion artifacts, metal artifacts, pulsation artifacts, quality of fat suppression, homogeneity of blood vessel signal intensity, and overall image quality) were evaluated using a 5-point scale (5 = excellent, 1 = unacceptable) by two observers for qualitative analysis. For comparisons between MS-SE and CS-3D-T1TFE, the paired t-test was used. RESULTS: The SNR of CS-3D-T1TFE was higher than or equal to that of MS-SE. The CS-3D-T1TFE scores for motion artifacts, pulsation artifacts, and homogeneity of blood vessel signal intensity were higher than the corresponding MS-SE scores in assessments by both observers. The MS-SE scores for fat suppression were higher than or equal to the CS-3D-T1TFE scores. There were no significant differences in lesion conspicuity, metal artifacts, and overall image quality between the two sequences. CONCLUSION: CS-3D-T1TFE imaging, less than 30&#37; of the scan time for MS-SE, showed no image degradation while retaining equal or higher SNR and image quality.

DOI： 10.1177/2058460120956644

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To assess the usefulness of amide proton transfer (APT) imaging in differentiating parotid tumors. MATERIAL AND METHODS: We retrospectively analyzed 43 histopathologically proven parotid solid tumors with diameters ≥2 cm. Twenty-one tumors were benign and 12 tumors were malignant. Two-dimensional APT imaging was performed using a saturation pulse with a duration of 2 s and a saturation power level of 2 μT. For acquiring Z-spectra, the imaging was repeated at 25 saturation frequency offsets from ω = -6 to +6 ppm with a step of 0.5 ppm as well as one scan acquired far off-resonance (-1560 ppm) for signal normalization. For the APT imaging, the asymmetry analysis at 3.5 ppm downfield from the water signal was calculated. The mean APT signal intensity (SI) was compared between the benign and malignant tumors. RESULTS: The mean APT SI was 2.23 ± 0.80 &#37; in the benign tumors and significantly higher at 2.99 ± 0.99 &#37; in the malignant tumors (P = 0.01). A receiver operating curve analysis revealed that the optimal APT SI threshold was 2.40 for distinguishing malignant tumors from benign tumors with an area under the curve of 0.74. The sensitivity, specificity, and accuracy were 83.3&#37;, 61.3&#37;, and 67.4&#37;, respectively. CONCLUSION: The mean APT SI of the malignant parotid tumors was significantly higher than that of the benign parotid tumors.

DOI： 10.1016/j.ejrad.2020.109047

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

There is a wide range of onset age in Alzheimer's disease (AD). Emerging evidence indicates variation of AD manifestations in oldest-old AD (OOAD); however, the pattern of cognitive dysfunctions remains unclear. We aimed to reveal cognitive performance characteristics and changes in brain functional connectivity in OOAD patients by a resting-state fMRI (rs-fMRI) study. We enrolled AD patients who had been referred to Kyushu University Hospital (KUH) or Sanno Hospital, and classified them into middle-old AD (MOAD) (65-79 years old) and OOAD (≥80 years old) according to the age of onset. Our subjects consisted of 19 OOAD, 17 MOAD, and 8 normal subjects. Cognitive performance was evaluated using Mini Mental State Examination-Japanese (MMSE-J) and Clinical Dementia Rating (CDR). rs-fMRI scanning and independent component analysis (ICA) were performed on Sanno Hospital patients and MOAD vs. OOAD patients were compared. The resulting significant regions were used as seeds for ROI-to-ROI analysis of the KUH dataset. Collectively, MMSE-J delayed recall sub-scores were significantly lower in OOAD patients compared with MOAD patients. ICA of the Sanno Hospital data indicated significant connectivity decrease in the default mode network (DMN) in the OOAD group compared with the MOAD group in the right superior parietal lobule (SPL). ROI-to-ROI analysis of the KUH dataset indicated significant disconnection in the OOAD group of the right SPL from the precuneus (p < 0.01). The functional connectivity from the right SPL to the precuneus was positively correlated with the MMSE-J delayed recall sub-score (p = 0.03) and negatively correlated with the CDR memory sub-scale (p = 0.04). These findings indicate that disconnection between the right SPL and the precuneus may contribute to worse memory capability in OOAD compared with MOAD.

DOI： 10.1016/j.heliyon.2020.e04516

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: Diffusion-weighted imaging (DWI) plays an important role in the preoperative assessment of gliomas; however, the diagnostic performance of histogram-derived parameters from mono-, bi-, and stretched-exponential DWI models in the grading of gliomas has not been fully investigated. Therefore, we compared these models' ability to differentiate between high-grade and low-grade gliomas. METHODS: This retrospective study included 22 patients with diffuse gliomas (age, 23-74 years; 12 males; 11 high-grade and 11 low-grade gliomas) who underwent preoperative 3 T-magnetic resonance imaging from October 2014 to August 2019. The apparent diffusion coefficient was calculated from the mono-exponential model. Using 13 b-values, the true-diffusion coefficient, pseudo-diffusion coefficient, and perfusion fraction were obtained from the bi-exponential model, and the distributed-diffusion coefficient and heterogeneity index were obtained from the stretched-exponential model. Region-of-interests were drawn on each imaging parameter map for subsequent histogram analyses. RESULTS: The skewness of the apparent diffusion, true-diffusion, and distributed-diffusion coefficients was significantly higher in high-grade than in low-grade gliomas (0.67 ± 0.67 vs. - 0.18 ± 0.63, 0.68 ± 0.74 vs. - 0.08 ± 0.66, 0.63 ± 0.72 vs. - 0.15 ± 0.73; P = 0.0066, 0.0192, and 0.0128, respectively). The 10th percentile of the heterogeneity index was significantly lower (0.77 ± 0.08 vs. 0.88 ± 0.04; P = 0.0004), and the 90th percentile of the perfusion fraction was significantly higher (12.64 ± 3.44 vs. 7.14 ± 1.70&#37;: P < 0.0001), in high-grade than in low-grade gliomas. The combination of the 10th percentile of the true-diffusion coefficient and 90th percentile of the perfusion fraction showed the best area under the receiver operating characteristic curve (0.96). CONCLUSION: The bi-exponential model exhibited the best diagnostic performance for differentiating high-grade from low-grade gliomas.

DOI： 10.1007/s00234-020-02456-2

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Cortical lesions (CLs) have a low prevalence and are associated with physical disabilities in Japanese patients with multiple sclerosis (MS). However, the contribution of CLs to cognitive impairment remains unclear in Asian MS. Sixty-one prospectively enrolled MS patients underwent three-dimensional double inversion recovery MR imaging, the Brief Repeatable Battery of Neuropsychological Tests (BRB-N), the Apathy Scale (AS), the Fatigue Questionnaire (FQ), and the Hospital Anxiety and Depression Scale (HADS) within a 1-week period. The cognitive impairment index (CII) score was calculated to measure patients' overall cognitive impairment. MS patients with CLs had poorer scores than those without CLs in most BRB-N tests, but scored comparably in the FQ, AS, and HADS. The number of CLs correlated negatively with all BRB-N test scores and positively with total CII scores. Leukocortical lesions were more extensively associated with cognitive dysfunction in various domains than intracortical lesions. Stepwise multiple regression analysis revealed that potential confounding factors for the highest quartile of CII score were the number of CLs (odds ratio 2.38, p = 0.0070) and the Expanded Disability Severity Scale score (odds ratio 2.13, p = 0.0003). Our results demonstrate that the presence and number of CLs are robustly associated with cognitive dysfunction in Asian MS patients.

DOI： 10.1038/s41598-020-61012-3

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Introduction: First-line bevacizumab (BEV) is now available as a treatment option for glioblastoma patients with severe clinical conditions in Japan. However, the survival benefits remain controversial. To elucidate these potential survival benefits, we retrospectively analyzed survival in glioblastoma patients receiving BEV. Methods: We analyzed survival in 120 patients with IDH-wild type glioblastoma treated from 2002 to 2018. Overall survival (OS) was assessed in three treatment era subgroups [pre-temozolomide (TMZ), TMZ, and TMZ–BEV], and the correlations of prognostic factors with survival were evaluated. Results: An improvement in survival was observed after BEV approval (median OS in the pre-TMZ, TMZ, and TMZ–BEV eras: 14.6, 14.9, and 22.1 months, respectively). A Cox proportional hazards model identified extent of resection and MGMT methylation status as significant prognostic factors in the TMZ era; however, these factors were not significant in the TMZ–BEV era. In subgroup analyses, patients with MGMT methylation had improved OS after TMZ introduction (pre-TMZ vs. TMZ, 18.5 vs. 28.1 months; P = 0.13), and those without MGMT methylation had significantly increased OS after BEV approval (TMZ vs. TMZ–BEV, 12.2 vs. 16.7 months; P = 0.04). Conclusions: Our findings imply that optional first-line administration of BEV can overcome the impact of conventional risk factors and prolong survival complementary to TMZ. The patient subgroups benefitting from TMZ and BEV did not seem to overlap, and stratification based on risk factors, including MGMT methylation status, might be effective for selecting patients in whom BEV should be preferentially used as a first-line therapy.

DOI： 10.1007/s11060-019-03339-0

記述言語：英語   掲載種別：研究論文（学術雑誌）  

INTRODUCTION: First-line bevacizumab (BEV) is now available as a treatment option for glioblastoma patients with severe clinical conditions in Japan. However, the survival benefits remain controversial. To elucidate these potential survival benefits, we retrospectively analyzed survival in glioblastoma patients receiving BEV. METHODS: We analyzed survival in 120 patients with IDH-wild type glioblastoma treated from 2002 to 2018. Overall survival (OS) was assessed in three treatment era subgroups [pre-temozolomide (TMZ), TMZ, and TMZ-BEV], and the correlations of prognostic factors with survival were evaluated. RESULTS: An improvement in survival was observed after BEV approval (median OS in the pre-TMZ, TMZ, and TMZ-BEV eras: 14.6, 14.9, and 22.1 months, respectively). A Cox proportional hazards model identified extent of resection and MGMT methylation status as significant prognostic factors in the TMZ era; however, these factors were not significant in the TMZ-BEV era. In subgroup analyses, patients with MGMT methylation had improved OS after TMZ introduction (pre-TMZ vs. TMZ, 18.5 vs. 28.1 months; P = 0.13), and those without MGMT methylation had significantly increased OS after BEV approval (TMZ vs. TMZ-BEV, 12.2 vs. 16.7 months; P = 0.04). CONCLUSIONS: Our findings imply that optional first-line administration of BEV can overcome the impact of conventional risk factors and prolong survival complementary to TMZ. The patient subgroups benefitting from TMZ and BEV did not seem to overlap, and stratification based on risk factors, including MGMT methylation status, might be effective for selecting patients in whom BEV should be preferentially used as a first-line therapy.

DOI： 10.1007/s11060-019-03339-0

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Background and purpose: Spiral MR imaging has several advantages compared with Cartesian MR imaging that can be leveraged for added clinical value. A multicenter multireader study was designed to compare spiral with standard-of-care Cartesian postcontrast structural brain MR imaging on the basis of relative performance in 10 metrics of image quality, artifact prevalence, and diagnostic benefit. Materials and methods: Seven clinical sites acquired 88 total subjects. For each subject, sites acquired 2 postcontrast MR imaging scans: a spiral 2D T1 spin-echo, and 1 of 4 routine Cartesian 2D T1 spin-echo/TSE scans (fully sampled spin-echo at 3T, 1.5T, partial Fourier, TSE). The spiral acquisition matched the Cartesian scan for scan time, geometry, and contrast. Nine neuroradiologists independently reviewed each subject, with the matching pair of spiral and Cartesian scans compared side-by-side, and scored on 10 image-quality metrics (5-point Likert scale) focused on intracranial assessment. The Wilcoxon signed rank test evaluated relative performance of spiral versus Cartesian, while the Kruskal-Wallis test assessed interprotocol differences. Results: Spiral was superior to Cartesian in 7 of 10 metrics (flow artifact mitigation, SNR, GM/WM contrast, image sharpness, lesion conspicuity, preference for diagnosing abnormal enhancement, and overall intracranial image quality), comparable in 1 of 10 metrics (motion artifacts), and inferior in 2 of 10 metrics (susceptibility artifacts, overall extracranial image quality) related to magnetic susceptibility (P < .05). Interprotocol comparison confirmed relatively higher SNR and GM/WM contrast for partial Fourier and TSE protocol groups, respectively (P < .05). Conclusions: Spiral 2D T1 spin-echo for routine structural brain MR imaging is feasible in the clinic with conventional scanners and was preferred by neuroradiologists for overall postcontrast intracranial evaluation.

DOI： 10.3174/ajnr.A6409

記述言語：英語   掲載種別：研究論文（学術雑誌）  

AIM: To compare the goodness of fit and correlations between diffusion kurtosis imaging (DKI) and a mono-exponential (ME) model, to compare the corrected apparent diffusion coefficient (D_app) and apparent kurtosis (K_app) of the DKI model, and the apparent diffusion coefficient (ADC) of the ME model among the various orofacial lesions, and to evaluate the diagnostic performances between the two models. MATERIALS AND METHODS: A total of 100 orofacial lesions underwent echo-planar diffusion magnetic resonance imaging (MRI) with four b-values. The goodness of fit was evaluated using Akaike information criterion. The correlations of the diffusion-derived parameters were evaluated. The diagnostic performance was analysed by receiver operating characteristics (ROC). RESULTS: The DKI model showed a significantly better goodness of fit than the ME model (p<0.0001). The K_app had a strongly negative correlation with the D_app (ρ=–0.749) and ADC (ρ=–0.938). A strongly positive correlation existed between the D_app and ADC (ρ=0.906). All parameters differed significantly between benign tumours and malignant tumours (p<0.05). In differentiating benign tumours from the malignant tumours, the AUC of D_app (0.871) was larger than that of ADC (0.805); however, a significant difference was not found (p=0.102). CONCLUSION: The DKI model had better goodness of fit than the ME model. Furthermore, the D_app and K_app were also characteristic for each pathological category; however, the DKI model did not yield a significantly higher diagnostic performance than the ME model, which might be related to the high correlation among the diffusion-derived parameters and wide variation among categories.

DOI： 10.1016/j.crad.2020.01.008

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.inat.2019.100498

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVES: The significance of conventional neuroimaging features for predicting molecular diagnosis and patient survival based on the updated World Health Organization (WHO) classification remains uncertain. We assessed the relevance of neuroimaging features (ring enhancement [RE], non-ring enhancement [non-RE], overall gadolinium enhancement [GdE], and intratumoral calcification [IC]) for molecular diagnosis and survival in glioma patients. PATIENTS AND METHODS: We evaluated 234 glioma patients according to the updated WHO classification. Isocitrate dehydrogenase (IDH), H3F3A, BRAF hotspot mutations, TERT promotor mutation, and chromosome 1p/19q co-deletion were examined. RE, non-RE, GdE, and IC were evaluated as significant neuroimaging findings. Kaplan-Meier analyses were performed to evaluate overall survival (OS) and the correlations of prognostic factors were evaluated by log-rank tests. Univariate and multivariate analyses were performed to detect prognostic factors for OS. RESULTS: A total of 207 patients were eligible. In 110 patients presenting RE, 102 (93&#37;) were glioblastoma (GBM), IDH-wild type. In 97 patients without RE, presence of GdE or IC were not significantly different between IDH-mutant and -wild type tumors, whereas presence of GdE was a significant indicator of higher WHO grades. IC was the only significant finding for 1p/19q co-deleted tumors. TERT promoter mutation was observed in 7/17 patients with diffuse astrocytic glioma, IDH-wild type; recently-defined as "molecular GBM." IC, RE, and GdE were observed with lower prevalence in molecular GBMs. While presence of RE, GdE, and absence of IC were significant factors of OS in overall cohort, presence of GdE was not significant in OS in cases without RE, and IDH-mutant tumors. IC was a significant predictor of favorable OS in cases without RE and IDH-wild type tumors. Multivariate analysis also validated these findings. CONCLUSION: GdE alone is not a significant predictor of IDH mutation status, but the pattern of enhancement is a significant predictor with RE demonstrating high sensitivity and specificity for GBM, IDH-wild type. Predicting "molecular GBM" by conventional neuroimaging is difficult. Moreover, GdE is not a significant factor of survival analyzed with pattern of enhancement or molecular stratifications. IC is an important radiographic finding for predicting molecular diagnosis and survival in glioma patients.

DOI： 10.1016/j.clineuro.2019.105556

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objectives: The significance of conventional neuroimaging features for predicting molecular diagnosis and patient survival based on the updated World Health Organization (WHO) classification remains uncertain. We assessed the relevance of neuroimaging features (ring enhancement [RE], non-ring enhancement [non-RE], overall gadolinium enhancement [GdE], and intratumoral calcification [IC]) for molecular diagnosis and survival in glioma patients. Patients and methods: We evaluated 234 glioma patients according to the updated WHO classification. Isocitrate dehydrogenase (IDH), H3F3A, BRAF hotspot mutations, TERT promotor mutation, and chromosome 1p/19q co-deletion were examined. RE, non-RE, GdE, and IC were evaluated as significant neuroimaging findings. Kaplan-Meier analyses were performed to evaluate overall survival (OS) and the correlations of prognostic factors were evaluated by log-rank tests. Univariate and multivariate analyses were performed to detect prognostic factors for OS. Results: A total of 207 patients were eligible. In 110 patients presenting RE, 102 (93%) were glioblastoma (GBM), IDH-wild type. In 97 patients without RE, presence of GdE or IC were not significantly different between IDH-mutant and -wild type tumors, whereas presence of GdE was a significant indicator of higher WHO grades. IC was the only significant finding for 1p/19q co-deleted tumors. TERT promoter mutation was observed in 7/17 patients with diffuse astrocytic glioma, IDH-wild type; recently-defined as “molecular GBM.” IC, RE, and GdE were observed with lower prevalence in molecular GBMs. While presence of RE, GdE, and absence of IC were significant factors of OS in overall cohort, presence of GdE was not significant in OS in cases without RE, and IDH-mutant tumors. IC was a significant predictor of favorable OS in cases without RE and IDH-wild type tumors. Multivariate analysis also validated these findings. Conclusion: GdE alone is not a significant predictor of IDH mutation status, but the pattern of enhancement is a significant predictor with RE demonstrating high sensitivity and specificity for GBM, IDH-wild type. Predicting “molecular GBM” by conventional neuroimaging is difficult. Moreover, GdE is not a significant factor of survival analyzed with pattern of enhancement or molecular stratifications. IC is an important radiographic finding for predicting molecular diagnosis and survival in glioma patients.

DOI： 10.1016/j.clineuro.2019.105556

記述言語：英語   掲載種別：研究論文（学術雑誌）  

AIM: To evaluate the diagnostic feasibility of probabilistic analysis using voxel-based morphometry (VBM) in differentiating primary central nervous system lymphoma (PCNSL) from glioblastoma (GBM). MATERIALS AND METHODS: In total, 118 patients with GBM (57 males, 61 females; mean [± standard deviation] age, 56.9±19.3 years; median, 61 years) and 52 patients with PCNSL (37 males, 15 females; mean age, 62±13.3 years, median, 66 years) were studied retrospectively. Each patient underwent preoperative contrast-enhanced T1-weighted imaging (CE-T1WI) using a 1.5 or 3 T magnetic resonance imaging (MRI) system. To assess preferential occurrence sites, images from CE-T1WI were co-registered and spatially normalised using the MNI152 T1 template. Subsequently, a region of interest (ROI) was placed in the centre of the enhancing tumour in normalised images with 1-mm isotropic resolution. The same ROI between normalised and T1 template images was set up using an ROI manager function in ImageJ software. A spherical volume of interest (VOI) with a radius of 10 mm was determined. A probability map was created by overlaying each image with the VOI. Each VOI was removed from T1 template images for VBM analysis. VBM analysis was performed using statistical parametric mapping (SPM) 12 software under default settings. RESULTS: VBM analysis showed significantly higher frequency in the splenium of the corpus callosum among PCNSL patients than among GBM patients (p<0.05; family-wise error correction). CONCLUSION: Topographic analysis using VBM provides useful information for differentiating PCNSL from GBM.

DOI： 10.1016/j.crad.2019.06.017

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To evaluate the performance of acceleration-selective arterial spin labeling (AccASL) MR angiography in the visualization of brain arteriovenous malformations (AVMs) in comparison with digital subtraction angiography (DSA) and time-of-flight (TOF) MR angiography. Methods: Twenty-one patients with brain AVM (mean age 31.1 ± 18.6 years; 11 males, 10 females) underwent TOF and AccASL MR angiography and DSA. Two neuroradiologists conducted an observer study for detection, nidus size, eloquence, venous drainage pattern, and Spetzler-Martin (SM) grade. The evaluations included the visualization of each AVM component with reference to DSA and assessments of contrast-to-noise ratio (CNR). The kappa statistic, repeated measures analysis of variance, Wilcoxon matched pairs test, and paired t test were used. Results: Both observers detected more AVMs with AccASL (95.2%, 90.5% for Observers 1 and 2) than with TOF (76.2% and 71.4%, respectively). The inter-modality agreement between AccASL and DSA was almost perfect for the eloquence, venous drainage pattern, and SM grade for Observer 1 and moderate for the venous drainage pattern and substantial for the eloquence and SM grade for Observer 2. The visualization scores were higher with AccASL than with TOF for the feeding artery (AccASL, 4.5 ± 1.0 vs. TOF, 3.9 ± 1.5, p = 0.0214), nidus (4.6 ± 1.1 vs. 3.2 ± 1.5, p = 0.0006), and draining vein (4.6 ± 1.0 vs. 2.2 ± 1.1, p < 0.0001), respectively. The CNRs in the nidus were higher in AccASL than in TOF (29.9 ± 16.7 vs. 20.8 ± 16.5, p = 0.0002), as in the draining vein (23.2 ± 13.0 vs. 12.6 ± 12.0, p = 0.0010), respectively. Conclusions: AccASL better visualized brain AVMs compared with TOF and was useful for grading without the use of contrast agents.

DOI： 10.1007/s00234-019-02217-w

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To evaluate the performance of acceleration-selective arterial spin labeling (AccASL) MR angiography in the visualization of brain arteriovenous malformations (AVMs) in comparison with digital subtraction angiography (DSA) and time-of-flight (TOF) MR angiography. METHODS: Twenty-one patients with brain AVM (mean age 31.1 ± 18.6 years; 11 males, 10 females) underwent TOF and AccASL MR angiography and DSA. Two neuroradiologists conducted an observer study for detection, nidus size, eloquence, venous drainage pattern, and Spetzler-Martin (SM) grade. The evaluations included the visualization of each AVM component with reference to DSA and assessments of contrast-to-noise ratio (CNR). The kappa statistic, repeated measures analysis of variance, Wilcoxon matched pairs test, and paired t test were used. RESULTS: Both observers detected more AVMs with AccASL (95.2&#37;, 90.5&#37; for Observers 1 and 2) than with TOF (76.2&#37; and 71.4&#37;, respectively). The inter-modality agreement between AccASL and DSA was almost perfect for the eloquence, venous drainage pattern, and SM grade for Observer 1 and moderate for the venous drainage pattern and substantial for the eloquence and SM grade for Observer 2. The visualization scores were higher with AccASL than with TOF for the feeding artery (AccASL, 4.5 ± 1.0 vs. TOF, 3.9 ± 1.5, p = 0.0214), nidus (4.6 ± 1.1 vs. 3.2 ± 1.5, p = 0.0006), and draining vein (4.6 ± 1.0 vs. 2.2 ± 1.1, p < 0.0001), respectively. The CNRs in the nidus were higher in AccASL than in TOF (29.9 ± 16.7 vs. 20.8 ± 16.5, p = 0.0002), as in the draining vein (23.2 ± 13.0 vs. 12.6 ± 12.0, p = 0.0010), respectively. CONCLUSIONS: AccASL better visualized brain AVMs compared with TOF and was useful for grading without the use of contrast agents.

DOI： 10.1007/s00234-019-02217-w

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: The purpose of this study was to identify magnetic resonance imaging (MRI) features that are associated with telomerase reverse transcriptase promoter mutation (TERTm) in glioblastoma. Materials and methods: A total of 112 patients with glioblastoma who had MRI at 1.5- or 3.0-T were retrospectively included. There were 43 patients with glioblastoma with wild-type TERT (TERTw) (22 men, 21 women; mean age, 47 ± 25 [SD] years; age range: 3–84 years) and 69 patients with glioblastoma with TERTm (34 men, 35 women; mean age 64 ± 11 [SD] years; age range, 41-–85 years). The feature vectors consist of 11 input units for two clinical parameters (age and gender) and nine MRI characteristics (tumor location, subventricular extension, cortical extension, multiplicity, enhancing volume, necrosis volume, the percentage of necrosis volume, minimum apparent diffusion coefficient [ADC] and normalized ADC). First, the diagnostic performance using univariate and multivariate logistic regression analyses was evaluated. Second, the cross-validation of the support vector machine (SVM) was performed by using leave-one-out method with 43 TERTw and 69 TERTm to evaluate the diagnostic performance. In addition, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for the differentiation between TERTw and TERTm were compared between logistic regression analysis and SVM. Results: With multivariate analysis, the percentage of necrosis volume and age were significantly greater in TERTm glioblastoma than in TERTw glioblastoma. SVM allowed discriminating between TERTw glioblastoma and TERTm glioblastoma with sensitivity, specificity, PPV, NPV, and accuracy of 85.7% [60/70; 95% confidence interval (CI): 75.3–92.9%], 54.8% (23/42; 95% CI: 38.7–70.2%), 75.9% (60/79; 95% CI: 69.1–81.7%), 69.7% (23/33; 95% CI: 54.9–81.3%) and 74.1% (83/112; 95% CI: 65.0–81.9%), respectively. Conclusion: The percentage of necrosis volume and age may surrogate for predicting TERT mutation status in glioblastoma.

DOI： 10.1016/j.diii.2019.02.010

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Computed DWI (cDWI) is a mathematical technique that calculates arbitrary higher b value images from at least two different lower b values. In addition, the removal of high intensity noise with image processing on cDWI could improve cholesteatoma-background contrast-to-noise ratio (CNR). In the present study, noise reduction was performed by the cut-off values of apparent diffusion coefficient (ADC) less than 0 and 0.4 × 10-3 s/mm2. The cholesteatoma to non-cholesteatoma CNR was increased using a noise reduction algorithm for clinical setting.

DOI： 10.2463/mrms.tn.2018-0068

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: A new sequence for intracranial MRA is developed, named enhanced acceleration-selective arterial spin labeling (eAccASL), to improve main artery visualization at middle cerebral artery (MCA). The aim of this study is to assess the visualization improvement using eAccASL, compared with the previously developed AccASL. Methods: eAccASL and AccASL were performed in 8 healthy volunteers and images were compared between the 2 sequences. One patient with Moyamoya disease was evaluated by eAccASL and time of flight. For the volunteer images, vessel visualization was assessed by measuring the contrast-to-noise ratio between MCA M1 to M4 and white matter and by counting the peripheral arteries. Venous artifact level was assessed by measuring the contrast-to-noise ratio between the confluence of the sinuses and white matter and by evaluating cortical vein visualization. For the patient images, qualitative assessment of peripheral and collateral vessel visualization was conducted. Results: In the MCA main trunk, higher arterial signal intensity, with reduced flow void, was observed in eAccASL compared with AccASL. Contrast-to-noise ratios of M1 to M3 for eAccASL were significantly higher than those of AccASL. There was no significant difference between AccASL and eAccASL for venous artifact. Conclusion: eAccASL could produce better MCA main trunk visualization compared with AccASL, while maintaining good venous signal suppression.

DOI： 10.1002/mrm.27603

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: A new sequence for intracranial MRA is developed, named enhanced acceleration-selective arterial spin labeling (eAccASL), to improve main artery visualization at middle cerebral artery (MCA). The aim of this study is to assess the visualization improvement using eAccASL, compared with the previously developed AccASL. METHODS: eAccASL and AccASL were performed in 8 healthy volunteers and images were compared between the 2 sequences. One patient with Moyamoya disease was evaluated by eAccASL and time of flight. For the volunteer images, vessel visualization was assessed by measuring the contrast-to-noise ratio between MCA M1 to M4 and white matter and by counting the peripheral arteries. Venous artifact level was assessed by measuring the contrast-to-noise ratio between the confluence of the sinuses and white matter and by evaluating cortical vein visualization. For the patient images, qualitative assessment of peripheral and collateral vessel visualization was conducted. RESULTS: In the MCA main trunk, higher arterial signal intensity, with reduced flow void, was observed in eAccASL compared with AccASL. Contrast-to-noise ratios of M1 to M3 for eAccASL were significantly higher than those of AccASL. There was no significant difference between AccASL and eAccASL for venous artifact. CONCLUSION: eAccASL could produce better MCA main trunk visualization compared with AccASL, while maintaining good venous signal suppression.

DOI： 10.1002/mrm.27603

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To investigate the binding potential of newly developed Annexin V-conjugated ultrasmall superparamagnetic iron oxide (V-USPIO) for detection of drug-induced apoptosis in vitro and in vivo. METHODS: Apoptotic cells induced by camptothecin were incubated with or without Annexin V-USPIO at a concentration of 0.089 mmol Fe/L in vitro. T2 values of the two cell suspensions were measured by 0.47T nuclear magnetic resonance (NMR) spectrometer. Tumor-bearing mice were subjected to 1.5T MR scanner at 2 h after intraperitoneal injection of etoposide and cyclophosphamide. Following the pre-contrast T1- and T2-weighted imaging (0 h), the post-contrast scan was performed at 2, 4, 6 and 24 h after intravenous injection of Annexin V-USPIO (100 μmol Fe/kg). As a control, MRI was also obtained at 4 h after injection of USPIO without Annexin V. The ratio of tumor signal intensity (SI) on post-MRI for that on pre-MRI (Post/Pre-SI ratio) was calculated. After scanning, tumors were resected for pathological analysis to evaluate the distribution of iron and apoptotic cells. RESULTS: The suspension of apoptotic cells incubated with Annexin V-USPIO showed shorter T2 value than that without it. On T1-weighted imaging post/pre-SI ratio at 4 h after injection of Annexin V-USPIO showed 1.46, while after injection of USPIO without Annexin V was 1.17. The similar distribution of iron and apoptotic cells was observed in concordance with high signal intensity area on post-T1-weighted imaging. CONCLUSION: A newly developed Annexin V-USPIO could have the potential for detection of drug-induced apoptosis.

DOI： 10.2463/mrms.mp.2017-0157

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Alzheimer’s disease (AD) patients exhibit various cognitive dysfunctions, including impairment of orientation for time (OT). The brain regions underlying OT impairment remain to be elucidated. A previous single-photon emission computed tomography study has indicated hypoperfusion of the posterior cingulate cortex (PCC) in relation to deterioration of OT. In this study, we investigated whole brain functional connectivity changes of PCC using resting-state functional magnetic resonance imaging. Voxel-based functional connectivity with PCC was analyzed in OT-poor or OT-good AD patients, classified according to the mean OT scores of the Mini-Mental State Examination subscale. The connectivities of dorsal frontal lobe, and lateral parietal and lateral temporal lobes with PCC in the right hemisphere were reduced in the OT-poor AD group compared with the OT-good AD group. A subtraction connectivity map of OT score differences (OT-good minus OT-poor) revealed the right middle temporal gyrus near the temporo-parietal junction as a significantly connected region with PCC. These results suggest that the right posterior part of the middle temporal gyrus may play an important role in OT in conjunction with PCC, and that disconnection between PCC and the right ventral attention network may cause OT disturbance in AD patients.

DOI： 10.1007/s11682-018-9860-x

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Alzheimer's disease (AD) patients exhibit various cognitive dysfunctions, including impairment of orientation for time (OT). The brain regions underlying OT impairment remain to be elucidated. A previous single-photon emission computed tomography study has indicated hypoperfusion of the posterior cingulate cortex (PCC) in relation to deterioration of OT. In this study, we investigated whole brain functional connectivity changes of PCC using resting-state functional magnetic resonance imaging. Voxel-based functional connectivity with PCC was analyzed in OT-poor or OT-good AD patients, classified according to the mean OT scores of the Mini-Mental State Examination subscale. The connectivities of dorsal frontal lobe, and lateral parietal and lateral temporal lobes with PCC in the right hemisphere were reduced in the OT-poor AD group compared with the OT-good AD group. A subtraction connectivity map of OT score differences (OT-good minus OT-poor) revealed the right middle temporal gyrus near the temporo-parietal junction as a significantly connected region with PCC. These results suggest that the right posterior part of the middle temporal gyrus may play an important role in OT in conjunction with PCC, and that disconnection between PCC and the right ventral attention network may cause OT disturbance in AD patients.

DOI： 10.1007/s11682-018-9860-x

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Background and Aim: The amount of proteins and peptides can be estimated with amide proton transfer (APT) imaging. Previous studies demonstrated the usefulness of APT imaging to predict tumor malignancy. We determined whether APT imaging can predict the tumor response to neoadjuvant chemotherapy (NAC) in patients with locally advanced rectal cancer (LARC). Methods: Seventeen patients with LARC who underwent a pretherapeutic magnetic resonance examination including APT imaging and NAC (at least two courses) were enrolled. The APT-weighted imaging (WI) signal intensity (SI) (%) was defined as magnetization transfer ratio asymmetry (MTR _asym ) at the offset of 3.5 ppm. Each tumor was histologically evaluated for the degree of degeneration and necrosis and then classified as one of five histological Grades (0, none; 1a, less than 1/3; 1b, 1/3 to 2/3; 2, more than 2/3; 3, all). We compared the mean APTWI SIs of the tumors between the Grade 0/1a/1b (low-response group) and Grade 2/3 (high-response group) by Student's t-test. We used receiver operating characteristics curves to determine the diagnostic performance of the APTWI SI for predicting the tumor response. Results: The mean APTWI SI of the low-response group (n = 12; 3.05 ± 1.61%) was significantly higher than that of the high-response group (n = 5; 1.14 ± 1.13%) (P = 0.029). The area under the curve for predicting the tumor response using the APTWI SI was 0.87. When ≥2.75% was used as an indicator of low-response status, 75% sensitivity and 100% specificity of the APTWI SI were obtained. Conclusion: Pretherapeutic APT imaging can predict the tumor response to NAC in patients with LARC.

DOI： 10.1111/jgh.14315

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To evaluate the visualization of CSF dynamics using the novel method multi-spin echo acquisition cine imaging (MUSACI). METHODS: MUSACI is based on multi-echo volume isotropic turbo spin-echo acquisition (VISTA) with pulse gating. MUSACI images were acquired in 11 healthy volunteers (7 men, 4 women; age range, 24-46 y, mean age, 31.9 ± 5.51 y). We compared the CSF signal intensities (SIs) at multiple values of the effective echo time (TEeff ) at the lateral ventricle, the foramen of Monro, the third ventricle, and the fourth ventricle. We compared the CSF SI changes in MUSACI at multiple TEeff and the mean velocities in phase contrast (PC) at each trigger delay at the foramen of Monro, the third ventricle, and the fourth ventricle. RESULTS: The anterograde CSF motion from the aqueduct to the fourth ventricle, the retrograde motion from the aqueduct to the third ventricle, and the retrograde motion from the foramen of Monro to the lateral ventricle were observed with MUSACI. The CSF SIs at each TEeff in the foramen of Monro, the third ventricle, and the fourth ventricle were significantly lower than that at each TEeff in the lateral ventricle (P < 0.05). The CSF SI in MUSACI changed with the TEeff , and the CSF movements were observed at each trigger delay in PC. CONCLUSION: MUSACI can provide both high-resolution anatomical detail of the CSF passageways and physiologic information regarding CSF dynamics in a single scan.

DOI： 10.1002/mrm.27394

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: MR neurography is known to be useful to evaluate nerve pathology. The purpose of this study was to evaluate the usefulness of simultaneous apparent T2 mapping and neurography with nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation enhancement imaging (SHINKEI) to distinguish patients with chronic inflammatory demyelinating polyneuropathy (CIDP) from healthy subjects. MATERIALS AND METHODS: This retrospective study included 13 patients with CIDP and five healthy subjects from 2015 to 2017. The T2 relaxation time and the size of the cervical ganglia and roots of the brachial plexus were measured. Statistical analyses were performed with the Mann-Whitney U test and receiver operating characteristics (ROC) analysis. RESULTS: The T2 relaxation times of the ganglia and roots were longer in patients with CIDP (119.31 ± 35.53 msec and 111.15 ± 33.82 msec) than in healthy subjects (101.42 ± 26.42 msec and 85.29 ± 13.22 msec, P = 0.0007 and P < 0.0001, respectively). The sizes of the ganglia and the roots were larger in patients with CIDP (6.25 ± 1.56 mm and 4.37 ± 1.71 mm) than in healthy subjects (5.59 ± 1.08 mm and 3.50 ± 0.62 mm, P = 0.0114 and P = 0.0014, respectively). ROC analysis revealed that T2 relaxation time of the roots was best at distinguishing CIDP patients from healthy subjects (the area under the curve = 0.748). CONCLUSION: Patients with CIDP could be distinguished from healthy subjects using simultaneous apparent T2 mapping and neurography with SHINKEI.

DOI： 10.1016/j.mri.2018.09.025

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND AND AIM: The amount of proteins and peptides can be estimated with amide proton transfer (APT) imaging. Previous studies demonstrated the usefulness of APT imaging to predict tumor malignancy. We determined whether APT imaging can predict the tumor response to neoadjuvant chemotherapy (NAC) in patients with locally advanced rectal cancer (LARC). METHODS: Seventeen patients with LARC who underwent a pretherapeutic magnetic resonance examination including APT imaging and NAC (at least two courses) were enrolled. The APT-weighted imaging (WI) signal intensity (SI) (&#37;) was defined as magnetization transfer ratio asymmetry (MTRasym ) at the offset of 3.5 ppm. Each tumor was histologically evaluated for the degree of degeneration and necrosis and then classified as one of five histological Grades (0, none; 1a, less than 1/3; 1b, 1/3 to 2/3; 2, more than 2/3; 3, all). We compared the mean APTWI SIs of the tumors between the Grade 0/1a/1b (low-response group) and Grade 2/3 (high-response group) by Student's t-test. We used receiver operating characteristics curves to determine the diagnostic performance of the APTWI SI for predicting the tumor response. RESULTS: The mean APTWI SI of the low-response group (n = 12; 3.05 ± 1.61&#37;) was significantly higher than that of the high-response group (n = 5; 1.14 ± 1.13&#37;) (P = 0.029). The area under the curve for predicting the tumor response using the APTWI SI was 0.87. When ≥2.75&#37; was used as an indicator of low-response status, 75&#37; sensitivity and 100&#37; specificity of the APTWI SI were obtained. CONCLUSION: Pretherapeutic APT imaging can predict the tumor response to NAC in patients with LARC.

DOI： 10.1111/jgh.14315

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To evaluate the visualization of CSF dynamics using the novel method multi-spin echo acquisition cine imaging (MUSACI). Methods: MUSACI is based on multi-echo volume isotropic turbo spin-echo acquisition (VISTA) with pulse gating. MUSACI images were acquired in 11 healthy volunteers (7 men, 4 women; age range, 24–46 y, mean age, 31.9 ± 5.51 y). We compared the CSF signal intensities (SIs) at multiple values of the effective echo time (TE _eff ) at the lateral ventricle, the foramen of Monro, the third ventricle, and the fourth ventricle. We compared the CSF SI changes in MUSACI at multiple TE _eff and the mean velocities in phase contrast (PC) at each trigger delay at the foramen of Monro, the third ventricle, and the fourth ventricle. Results: The anterograde CSF motion from the aqueduct to the fourth ventricle, the retrograde motion from the aqueduct to the third ventricle, and the retrograde motion from the foramen of Monro to the lateral ventricle were observed with MUSACI. The CSF SIs at each TE _eff in the foramen of Monro, the third ventricle, and the fourth ventricle were significantly lower than that at each TE _eff in the lateral ventricle (P < 0.05). The CSF SI in MUSACI changed with the TE _eff , and the CSF movements were observed at each trigger delay in PC. Conclusion: MUSACI can provide both high-resolution anatomical detail of the CSF passageways and physiologic information regarding CSF dynamics in a single scan.

DOI： 10.1002/mrm.27394

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: MR neurography is known to be useful to evaluate nerve pathology. The purpose of this study was to evaluate the usefulness of simultaneous apparent T2 mapping and neurography with nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation enhancement imaging (SHINKEI) to distinguish patients with chronic inflammatory demyelinating polyneuropathy (CIDP) from healthy subjects. Materials and methods: This retrospective study included 13 patients with CIDP and five healthy subjects from 2015 to 2017. The T2 relaxation time and the size of the cervical ganglia and roots of the brachial plexus were measured. Statistical analyses were performed with the Mann-Whitney U test and receiver operating characteristics (ROC) analysis. Results: The T2 relaxation times of the ganglia and roots were longer in patients with CIDP (119.31 ± 35.53 msec and 111.15 ± 33.82 msec) than in healthy subjects (101.42 ± 26.42 msec and 85.29 ± 13.22 msec, P = 0.0007 and P < 0.0001, respectively). The sizes of the ganglia and the roots were larger in patients with CIDP (6.25 ± 1.56 mm and 4.37 ± 1.71 mm) than in healthy subjects (5.59 ± 1.08 mm and 3.50 ± 0.62 mm, P = 0.0114 and P = 0.0014, respectively). ROC analysis revealed that T2 relaxation time of the roots was best at distinguishing CIDP patients from healthy subjects (the area under the curve = 0.748). Conclusion: Patients with CIDP could be distinguished from healthy subjects using simultaneous apparent T2 mapping and neurography with SHINKEI.

DOI： 10.1016/j.mri.2018.09.025

記述言語：英語   掲載種別：研究論文（学術雑誌）  

There may be different neural bases between subjects with epilepsy only (EP) and interictal chronic epilepsy psychosis (EPS). However, there have been few structural MRI studies of EPS. The current study was conducted to investigate the neural substrate of EPS. T1-weighted images were analyzed in 14 patients with EPS and 14 strictly-matched patients with EP. We conducted volume comparison in the whole brain using voxel-based morphometry (VBM). The VBM method revealed that EPS patients exhibited significantly reduced gray matter volumes in the left postcentral gyrus and the left supra marginal gyrus compared with EP patients (adjusted p = 0.029, FDR corrected q; k = 319 voxels). For clinical correlations, there were no significant associations between psychotic symptoms and gray matter volumes in the left postcentral gyrus and the left supra marginal gyrus. VBM analysis revealed that reduced gray matter volumes in the left postcentral gyrus and the left supra marginal gyrus may be crucial regions for EPS.

DOI： 10.1007/s11682-019-00044-4

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND AND PURPOSE: Intravoxel incoherent motion imaging, which simultaneously measures diffusion and perfusion parameters, is promising for brain tumor grading. However, intravoxel incoherent motion imaging has not been tested in children. The purpose of this study was to evaluate the correlation between intravoxel incoherent motion parameters and histology to assess the accuracy of intravoxel incoherent motion imaging for pediatric intracranial tumor grading. MATERIALS AND METHODS: Between April 2013 and September 2015, 17 children (11 boys, 6 girls; 2 months to 15 years of age) with intracranial tumors were included in this retrospective study. Intravoxel incoherent motion parameters were fitted using 13 b-values for a biexponential model. The perfusion-free diffusion coefficient, pseudodiffusion coefficient, and perfusion fraction were measured in highand low-grade tumors. These intravoxel incoherent motion parameters and the ADC were compared using the unpaired t test. The correlations between the intravoxel incoherent motion parameters and microvessel density or the MIB-1 index were analyzed using the Spearman correlation test. Receiver operating characteristic analysis was used to evaluate diagnostic performance. RESULTS: The perfusion-free diffusion coefficient and ADC were lower in high-grade than in low-grade tumors (perfusion-free diffusion coefficient, 0.85 ± 0.40 versus 1.53 ± 0.21 × 10^-3 mm²/s, P < .001; ADC, 1.04 ± 0.33 versus 1.60 ± 0.21 × 10^-3 mm²/s, P < .001). The pseudodiffusion coefficient showed no difference between the groups. The perfusion fraction was higher in high-grade than in low-grade tumors (21.7 ± 8.2% versus 7.6 ± 4.3%, P < .001). Receiver operating characteristic analysis found that the combined perfusion-free diffusion coefficient and perfusion fraction had the best diagnostic performance for tumor differentiation (area under the curve=0.986). CONCLUSIONS: Intravoxel incoherent motion imaging reflects tumor histology and may be a helpful, noninvasive method for pediatric intracranial tumor grading.

DOI： 10.3174/ajnr.A6052

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To investigate the binding potential of newly developed Annexin V-conjugated ultrasmall superparamagnetic iron oxide (V-USPIO) for detection of drug-induced apoptosis in vitro and in vivo. Methods: Apoptotic cells induced by camptothecin were incubated with or without Annexin V-USPIO at a concentration of 0.089 mmol Fe/L in vitro. T2 values of the two cell suspensions were measured by 0.47T nuclear magnetic resonance (NMR) spectrometer. Tumor-bearing mice were subjected to 1.5T MR scanner at 2 h after intraperitoneal injection of etoposide and cyclophosphamide. Following the pre-contrast T₁- and T₂-weighted imaging (0 h), the post-contrast scan was performed at 2, 4, 6 and 24 h after intravenous injection of Annexin V-USPIO (100 μmol Fe/kg). As a control, MRI was also obtained at 4 h after injection of USPIO without Annexin V. The ratio of tumor signal intensity (SI) on post-MRI for that on pre-MRI (Post/Pre-SI ratio) was calculated. After scanning, tumors were resected for pathological analysis to evaluate the distribution of iron and apoptotic cells. Results: The suspension of apoptotic cells incubated with Annexin V-USPIO showed shorter T₂ value than that without it. On T1-weighted imaging post/pre-SI ratio at 4 h after injection of Annexin V-USPIO showed 1.46, while after injection of USPIO without Annexin V was 1.17. The similar distribution of iron and apoptotic cells was observed in concordance with high signal intensity area on post-T1-weighted imaging. Conclusion: A newly developed Annexin V-USPIO could have the potential for detection of drug-induced apoptosis.

DOI： 10.2463/mrms.mp.2017-0157

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Computed DWI (cDWI) is a mathematical technique that calculates arbitrary higher b value images from at least two different lower b values. In addition, the removal of high intensity noise with image processing on cDWI could improve cholesteatoma-background contrast-to-noise ratio (CNR). In the present study, noise reduction was performed by the cut-off values of apparent diffusion coefficient (ADC) less than 0 and 0.4 × 10⁻³ s/mm². The cholesteatoma to non-cholesteatoma CNR was increased using a noise reduction algorithm for clinical setting.

DOI： 10.2463/mrms.tn.2018-0068

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Background: Impaired cognitive flexibility has been implicated in the genetic basis of obsessive-compulsive disorder (OCD). Recent endophenotype studies of OCD showed neural inefficiency in the cognitive control network and interference by the limbic network of the cognitive control network. Exploring the relationship between the functional brain network and impaired cognitive flexibility may provide novel information about the neurobiological basis of OCD. Methods: We obtained resting-state functional magnetic resonance imaging (rsfMRI) scans and measured the cognitive flexibility of 37 medication-free OCD patients and 40 healthy control (HC) participants using the Wisconsin Card Sorting Test (WCST). We explored the difference between OCD and HC groups in the functional brain network related to impaired cognitive flexibility from the amygdala and dorsal striatal regions of interest (ROIs) by using a seed-based approach. Results: Significant differences between the OCD and HC groups were identified in the resting state functional network from the dorsal caudate. Increased functional connectivity from the dorsal caudate to the dorsal anterior cingulate cortex (dACC) and anterior insula (AI) was associated with poorer cognitive flexibility in the OCD group, but better cognitive flexibility in the HC group. Conclusions: These results provide evidence that the impaired cognitive flexibility of OCD may be associated with dysfunctions of the brain network from the dorsal caudate (DC) to important nodes of the salience network. Our results extend the neuropsychological model of OCD by showing intrinsically different associations between OCD and HC in functional network and cognitive flexibility.

DOI： 10.1016/j.nicl.2019.102004

記述言語：英語   掲載種別：研究論文（学術雑誌）  

In this study, we evaluated the efficacy of intravoxel incoherent motion (IVIM)-derived parameters calculated with three b-values in differentiating high-grade gliomas (HGGs) from low-grade gliomas (LGGs) by comparing those calculated with multiple b-values. Ten patients with LGG (ages 35.1±12.1 yrs; 4 males, 6 females) and 21 patients with HGG (ages 60.6±19.1 yrs; 10 males, 11 females) who underwent subsequent surgical resections were examined with both IVIM imaging and histopathological analysis. The IVIM diffusion-weighted imaging was conducted using a single-shot echo planar sequence with 13 b-factors (0, 10, 20, 30, 50, 80, 100, 200, 300, 400, 600, 800, and 1000 sec/mm ² ) at 3T. In the conventional IVIM analysis, the perfusion fraction (f) and true diffusion coefficient (D) were calculated by biexponential fitting model with 13 b-values. In the simplified method with the selected three b-values (0, 300, and 1000 sec/mm ² ), D simply corresponds to the slope of a straight line passing through two logarithmic signal intensities (SIs) at the b-values of 300 and 1000 s/mm ² , and f corresponds to the difference between the intercept of this line and SI at the b-value of 0 sec/mm ² . The maximum f (f-max) and minimum D (D-min) was measured in each tumor. The f-max values calculated with three b-values (12.8±5.9%) were significantly lower than those with 13 b-values (17.3±7.5%, p<0.0001), but a good correlation and agreement were observed between these sets of f-max values (r = 0.79, ICC = 0.87). In the IVIM imaging with both three and 13 b-values, the HGGs showed significantly higher f-max values compared to the LGGs (p<0.001, respectively). The D-min values calculated with three b-values (1.06±0.31 ×10 ⁻³ mm ² /sec) was not different from those with 13 b-values (1.07±0.33 ×10 ⁻³ mm ² /sec), and an excellent correlation and agreement were found between them (r = 0.99, ICC = 0.99). The simplified IVIM imaging using three b-values can efficiently differentiate HGGs and LGGs.

DOI： 10.1371/journal.pone.0209796

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE:: To evaluate the usefulness of simultaneous T2 mapping and neurography with nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation enhancement imaging (SHINKEI) in the lumbar plexus to distinguish patients with chronic inflammatory demyelinating polyneuropathy (CIDP) from healthy controls. METHODS:: Our institutional review boards approved this retrospective study, and written informed consent was waived. 10 patients with CIDP from 2015 to 2017 were studied along with 5 healthy controls on a 3 T scanner. The T2 relaxation time and the size of the dorsal root ganglia and nerves of the lumbar plexus at L3-S1 were measured. Statistical analyses were performed with the Mann-Whitney U test and a receiver operating characteristics analysis. RESULTS:: The T2 relaxation times of the dorsal root ganglia and the nerves of the lumbar plexus were longer in the CIDP patients (133.34  ±  41.36 and 130.40 ± 47.78 ms) compared to the healthy controls (114.69 ± 24.90 and 83.72 ± 17.51 ms, p = 0.0265 and p < 0.0001, respectively). The sizes of the nerves were larger in the CIDP patients (6.19  ±  2.28 mm) compared to the controls (4.54  ±  0.86 mm, p < 0.0001). However, there was no significant difference between the sizes of the ganglia in the CIDP patients and the controls. The receiver operating characteristics analysis revealed that the T2 relaxation time of the nerves was best at distinguishing the CIDP patients from the controls (Az  =  0.848). CONCLUSION:: Patients with CIDP could be distinguished from healthy controls using simultaneous T2 mapping and neurography with SHINKEI in the lumbar plexus. ADVANCES IN KNOWLEDGE:: Patients with CIDP could be distinguished from healthy controls using simultaneous T2 mapping and neurography with SHINKEI in the lumbar plexus.

DOI： 10.1259/bjr.20180501

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objectives: To evaluate the performance of four-dimensional pseudo-continuous arterial spin labeling (4D-pCASL)-based angiography using CENTRA-keyhole and view sharing (4D-PACK) in the visualization of flow dynamics in distal cerebral arteries and leptomeningeal anastomosis (LMA) collaterals in moyamoya disease in comparison with contrast inherent inflow-enhanced multiphase angiography (CINEMA), with reference to digital subtraction angiography (DSA). Methods: Thirty-two cerebral hemispheres from 19 patients with moyamoya disease (mean age, 29.7 ± 19.6 years; five males, 14 females) underwent both 4D-MR angiography and DSA. Qualitative evaluations included the visualization of anterograde middle cerebral artery (MCA) flow and retrograde flow via LMA collaterals with reference to DSA. Quantitative evaluations included assessments of the contrast-to-noise ratio (CNR) on these vessels. The linear mixed-effect model was used to compare the 4D-PACK and CINEMA methods. Results: The vessel visualization scores were significantly higher with 4D-PACK than with CINEMA in the visualization of anterograde flow for both Observer 1 (CINEMA, 3.53 ± 1.39; 4D-PACK, 4.53 ± 0.80; p < 0.0001) and Observer 2 (CINEMA, 3.50±1.39; 4D-PACK, 4.31 ± 0.86; p = 0.0009). The scores were higher with 4D-PACK than with CINEMA in the visualization of retrograde flow for both Observer 1 (CINEMA, 3.44 ± 1.05; 4D-PACK, 4.47 ± 0.88; p < 0.0001) and Observer 2 (CINEMA, 3.19 ± 1.20; 4D-PACK, 4.38 ± 0.91; p < 0.0001). The maximum CNR in the anterograde flow was higher in 4D-PACK (40.1 ± 16.1, p = 0.0001) than in CINEMA (27.0 ± 16.6). The maximum CNR in the retrograde flow was higher in 4D-PACK (36.1 ± 10.0, p < 0.0001) than in CINEMA (15.4 ± 8.0). Conclusions: The 4D-PACK provided better visualization and higher CNRs in distal cerebral arteries and LMA collaterals compared with CINEMA in patients with this disease. Key Points: • The 4D-PACK enables good visualization of distal cerebral arteries in moyamoya disease. • The 4D-PACK enables direct visualization of leptomeningeal collateral vessels in moyamoya disease. • Vessel visualization by 4D-PACK can be useful in assessing cerebral hemodynamics.

DOI： 10.1007/s00330-018-5462-7

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: Ultrahigh-resolution CT (U-HRCT) provides better spatial resolution than conventional multi-detector row CT (ConvCT) and could be expected to identify microstructures with its 0.25-mm collimation, 1792 channels and 160 detector rows, 0.4 × 0.5 mm focus size, and a 1024 matrix. The aim of the study was to evaluate key anatomic structures in temporal bone using U-HRCT comparing it to ConvCT. MATERIALS AND METHODS: A total of 30 patients (14 males and 16 females; age range, 8-82 years; median 49 years) underwent both U-HRCT and ConvCT. All CT images were obtained with 0.5 mm section thickness and a 512 × 512 matrix, and field of view of 80 mm. Transverse scans were acquired in a plane parallel to the orbitomeatal plane in the helical mode with 120 kV. Images of the 30 temporal bones of unaffected side were reviewed by two independent neuroradiologists who rated the visibility of key anatomic structures for both U-HRCT and ConvCT. The ratings between U-HRCT and ConvCT were compared using Wilcoxon matched-pairs signed rank test. The interobserver agreement on the rating of stapedius tendon was evaluated using weighted κ statistics. RESULTS: Excellent interobserver agreement was shown for U-HRCT (κ = 0.920), whereas good agreement was obtained for ConvCT (κ = 0.733). According to both observers, stapedius tendon was more clearly visualized using U-HRCT than ConvCT (p < 0.0001). All other anatomic structures were well visualized using both CT scanners. CONCLUSION: The anatomy of temporal bone is more conspicuous on U-HRCT than on ConvCT because of its ultra-high-resolution detector. U-HRCT may provide beneficial information for determining surgical indication or procedures.

DOI： 10.1007/s00405-018-5101-6

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVES: To evaluate the performance of four-dimensional pseudo-continuous arterial spin labeling (4D-pCASL)-based angiography using CENTRA-keyhole and view sharing (4D-PACK) in the visualization of flow dynamics in distal cerebral arteries and leptomeningeal anastomosis (LMA) collaterals in moyamoya disease in comparison with contrast inherent inflow-enhanced multiphase angiography (CINEMA), with reference to digital subtraction angiography (DSA). METHODS: Thirty-two cerebral hemispheres from 19 patients with moyamoya disease (mean age, 29.7 ± 19.6 years; five males, 14 females) underwent both 4D-MR angiography and DSA. Qualitative evaluations included the visualization of anterograde middle cerebral artery (MCA) flow and retrograde flow via LMA collaterals with reference to DSA. Quantitative evaluations included assessments of the contrast-to-noise ratio (CNR) on these vessels. The linear mixed-effect model was used to compare the 4D-PACK and CINEMA methods. RESULTS: The vessel visualization scores were significantly higher with 4D-PACK than with CINEMA in the visualization of anterograde flow for both Observer 1 (CINEMA, 3.53 ± 1.39; 4D-PACK, 4.53 ± 0.80; p < 0.0001) and Observer 2 (CINEMA, 3.50±1.39; 4D-PACK, 4.31 ± 0.86; p = 0.0009). The scores were higher with 4D-PACK than with CINEMA in the visualization of retrograde flow for both Observer 1 (CINEMA, 3.44 ± 1.05; 4D-PACK, 4.47 ± 0.88; p < 0.0001) and Observer 2 (CINEMA, 3.19 ± 1.20; 4D-PACK, 4.38 ± 0.91; p < 0.0001). The maximum CNR in the anterograde flow was higher in 4D-PACK (40.1 ± 16.1, p = 0.0001) than in CINEMA (27.0 ± 16.6). The maximum CNR in the retrograde flow was higher in 4D-PACK (36.1 ± 10.0, p < 0.0001) than in CINEMA (15.4 ± 8.0). CONCLUSIONS: The 4D-PACK provided better visualization and higher CNRs in distal cerebral arteries and LMA collaterals compared with CINEMA in patients with this disease. KEY POINTS: • The 4D-PACK enables good visualization of distal cerebral arteries in moyamoya disease. • The 4D-PACK enables direct visualization of leptomeningeal collateral vessels in moyamoya disease. • Vessel visualization by 4D-PACK can be useful in assessing cerebral hemodynamics.

DOI： 10.1007/s00330-018-5462-7

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objective: Ultrahigh-resolution CT (U-HRCT) provides better spatial resolution than conventional multi-detector row CT (ConvCT) and could be expected to identify microstructures with its 0.25-mm collimation, 1792 channels and 160 detector rows, 0.4 × 0.5 mm focus size, and a 1024 matrix. The aim of the study was to evaluate key anatomic structures in temporal bone using U-HRCT comparing it to ConvCT. Materials and methods: A total of 30 patients (14 males and 16 females; age range, 8–82 years; median 49 years) underwent both U-HRCT and ConvCT. All CT images were obtained with 0.5 mm section thickness and a 512 × 512 matrix, and field of view of 80 mm. Transverse scans were acquired in a plane parallel to the orbitomeatal plane in the helical mode with 120 kV. Images of the 30 temporal bones of unaffected side were reviewed by two independent neuroradiologists who rated the visibility of key anatomic structures for both U-HRCT and ConvCT. The ratings between U-HRCT and ConvCT were compared using Wilcoxon matched-pairs signed rank test. The interobserver agreement on the rating of stapedius tendon was evaluated using weighted κ statistics. Results: Excellent interobserver agreement was shown for U-HRCT (κ = 0.920), whereas good agreement was obtained for ConvCT (κ = 0.733). According to both observers, stapedius tendon was more clearly visualized using U-HRCT than ConvCT (p < 0.0001). All other anatomic structures were well visualized using both CT scanners. Conclusion: The anatomy of temporal bone is more conspicuous on U-HRCT than on ConvCT because of its ultra-high-resolution detector. U-HRCT may provide beneficial information for determining surgical indication or procedures.

DOI： 10.1007/s00405-018-5101-6

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.diii.2018.05.007

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objectives: ASL is useful in evaluating tumour blood flow and in detecting hypervascular tumours. The purpose of this study was to assess the additive value of ASL to non-contrast and contrast-enhanced (NC/CE)-T1WI for diagnosing residual or recurrent meningiomas. Methods: This retrospective study included 25 postoperative patients (20 women, 5 men; median age, 65 [32–85] years) with and 25 gender- and age-matched postoperative patients without residual or recurrent meningiomas. ASL was performed using a pseudocontinuous method. Seven independent observers (two radiology residents, two general radiologists and three neuroradiologists) participated in two reading sessions consisting of only NC/CE-T1WI (first session) or NC/CE-T1WI with ASL (second session). We evaluated the sensitivity and diagnostic performance for the detection of residual or recurrent meningiomas. The diagnostic performance was assessed using a figure of merit (FOM) calculated via jackknife free-response receiver-operating characteristics. Statistical analysis was performed with paired t tests, with a significance level of p <.05. Results: The sensitivities were as follows (NC/CE-T1WI vs. NC/CE-T1WI with ASL): residents (62.1% vs. 70.7%), general radiologists (75.9% vs. 87.9%), neuroradiologists (97.7% vs. 100%) and all observers (81.3% vs. 88.2%). The FOMs were as follows (NC/CE-T1WI vs. NC/CE-T1WI with ASL): residents (0.76 vs. 0.83), general radiologists (0.83 vs. 0.93), neuroradiologists (0.95 vs. 0.99) and all observers (0.86 vs. 0.93). The addition of ASL significantly improved the diagnostic parameters for all observers except neuroradiologists (p <. 05). Conclusions: ASL improved the detection rate of residual or recurrent meningiomas on NC/CE-T1WI among both radiology residents and general radiologists. Key Points: • ASL improved diagnostic performance for residual/recurrent meningioma compare to NC/CE-T1WI alone. • Diagnostic sensitivity was increased after adding ASL compared with NC/CE-T1WI. • FOM was increased after adding ASL compared with NC/CE-T1WI.

DOI： 10.1007/s00330-018-5404-4

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVES: ASL is useful in evaluating tumour blood flow and in detecting hypervascular tumours. The purpose of this study was to assess the additive value of ASL to non-contrast and contrast-enhanced (NC/CE)-T1WI for diagnosing residual or recurrent meningiomas. METHODS: This retrospective study included 25 postoperative patients (20 women, 5 men; median age, 65 [32-85] years) with and 25 gender- and age-matched postoperative patients without residual or recurrent meningiomas. ASL was performed using a pseudocontinuous method. Seven independent observers (two radiology residents, two general radiologists and three neuroradiologists) participated in two reading sessions consisting of only NC/CE-T1WI (first session) or NC/CE-T1WI with ASL (second session). We evaluated the sensitivity and diagnostic performance for the detection of residual or recurrent meningiomas. The diagnostic performance was assessed using a figure of merit (FOM) calculated via jackknife free-response receiver-operating characteristics. Statistical analysis was performed with paired t tests, with a significance level of p < .05. RESULTS: The sensitivities were as follows (NC/CE-T1WI vs. NC/CE-T1WI with ASL): residents (62.1&#37; vs. 70.7&#37;), general radiologists (75.9&#37; vs. 87.9&#37;), neuroradiologists (97.7&#37; vs. 100&#37;) and all observers (81.3&#37; vs. 88.2&#37;). The FOMs were as follows (NC/CE-T1WI vs. NC/CE-T1WI with ASL): residents (0.76 vs. 0.83), general radiologists (0.83 vs. 0.93), neuroradiologists (0.95 vs. 0.99) and all observers (0.86 vs. 0.93). The addition of ASL significantly improved the diagnostic parameters for all observers except neuroradiologists (p <. 05). CONCLUSIONS: ASL improved the detection rate of residual or recurrent meningiomas on NC/CE-T1WI among both radiology residents and general radiologists. KEY POINTS: • ASL improved diagnostic performance for residual/recurrent meningioma compare to NC/CE-T1WI alone. • Diagnostic sensitivity was increased after adding ASL compared with NC/CE-T1WI. • FOM was increased after adding ASL compared with NC/CE-T1WI.

DOI： 10.1007/s00330-018-5404-4

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To prospectively investigate the ability of amide proton transfer (APT) imaging, in comparison with that of diffusion-weighted imaging (DWI), to predict pathological factors in rectal cancer. Materials and methods: Twenty-two patients who underwent MR examination including APT imaging and DWI for evaluation of rectal cancer were enrolled. APT signal intensity (SI) was defined as the magnetization transfer asymmetry at 3.5 ppm and was mapped. An apparent diffusion coefficient (ADC) map was generated using b-values of 0, 500 and 1000 s/mm ² . APT SI and ADC were calculated by placing regions-of-interest in the tumors on these maps. Pathological factors including tumor size and tumor grade were also evaluated. Average APT SIs or ADCs were compared between the two groups classified based on each pathological factor using Student's t-test. Results: The average APT SI of tumors with diameters of 5 cm or more (3.09 ± 1.41%) was significantly higher than that of tumors with diameters < 5 cm (1.83 ± 1.38%). In addition, the average APT SI of moderately differentiated adenocarcinoma (2.82 ± 1.51%) was significantly higher than that of well-differentiated adenocarcinoma (1.24 ± 0.57%). There was no difference in ADC between groups classified based on any pathological factor. Conclusion: Amide proton transfer imaging can predict tumor grade in rectal cancer.

DOI： 10.1016/j.mri.2018.04.017

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To prospectively investigate the ability of amide proton transfer (APT) imaging, in comparison with that of diffusion-weighted imaging (DWI), to predict pathological factors in rectal cancer. MATERIALS AND METHODS: Twenty-two patients who underwent MR examination including APT imaging and DWI for evaluation of rectal cancer were enrolled. APT signal intensity (SI) was defined as the magnetization transfer asymmetry at 3.5 ppm and was mapped. An apparent diffusion coefficient (ADC) map was generated using b-values of 0, 500 and 1000 s/mm2. APT SI and ADC were calculated by placing regions-of-interest in the tumors on these maps. Pathological factors including tumor size and tumor grade were also evaluated. Average APT SIs or ADCs were compared between the two groups classified based on each pathological factor using Student's t-test. RESULTS: The average APT SI of tumors with diameters of 5 cm or more (3.09 ± 1.41&#37;) was significantly higher than that of tumors with diameters < 5 cm (1.83 ± 1.38&#37;). In addition, the average APT SI of moderately differentiated adenocarcinoma (2.82 ± 1.51&#37;) was significantly higher than that of well-differentiated adenocarcinoma (1.24 ± 0.57&#37;). There was no difference in ADC between groups classified based on any pathological factor. CONCLUSION: Amide proton transfer imaging can predict tumor grade in rectal cancer.

DOI： 10.1016/j.mri.2018.04.017

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: 4D dynamic MR angiography (4D-MRA) using pseudo-continuous arterial spin labeling (pCASL), combined with Keyhole and View-sharing (4D-PACK) for scan acceleration, is introduced. Its validity for arterial inflow dynamics visualization was investigated through comparison with 4D-pCASL and contrast inherent inflow enhanced multiphase angiography (CINEMA). Methods: Six healthy volunteers were included in the study. The arterial transit time (ATT) in 4D-PACK was measured at multiple regions in middle cerebral artery (MCA), and Pearson's correlation coefficient with ATT in 4D-pCASL was calculated. The contrast-to-noise ratio (CNR) in 4D-PACK was measured in four MCA segments and compared with that in 4D-pCASL and CINEMA. Arterial visualization in 4D-PACK was assessed qualitatively in patients with moyamoya disease and arteriovenous malformation by comparing with CINEMA. Results: 4D-PACK achieved a 36% scan time reduction compared with 4D-pCASL. The correlation coefficient for ATT measured by 4D-pCASL and 4D-PACK was greater than 0.96. The CNR was significantly higher using 4D-PACK compared with CINEMA in the M4 segment (P < 0.01). In patient examinations, the flow in the collateral artery or draining vein was better visualized in 4D-PACK compared with CINEMA. Conclusion: 4D-PACK accelerates 4D-pCASL, shows similar inflow dynamics as 4D-pCASL and shows better peripheral visualization compared with CINEMA. Magn Reson Med 80:719–725, 2018.

DOI： 10.1002/mrm.27074

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: To investigate the optimal monochromatic color combination for fusion imaging of FDG-PET and diffusion-weighted MR images (DW) regarding lesion conspicuity of each image. METHODS: Six linear monochromatic color-maps of red, blue, green, cyan, magenta, and yellow were assigned to each of the FDG-PET and DW images. Total perceptual color differences of the lesions were calculated based on the lightness and chromaticity measured with the photometer. Visual lesion conspicuity was also compared among the PET-only, DW-only and PET-DW-double positive portions with mean conspicuity scores. Statistical analysis was performed with a one-way analysis of variance and Spearman's rank correlation coefficient. RESULTS: Among all the 12 possible monochromatic color-map combinations, the 3 combinations of red/cyan, magenta/green, and red/green produced the highest conspicuity scores. Total color differences between PET-positive and double-positive portions correlated with conspicuity scores (ρ = 0.2933, p < 0.005). Lightness differences showed a significant negative correlation with conspicuity scores between the PET-only and DWI-only positive portions. Chromaticity differences showed a marginally significant correlation with conspicuity scores between DWI-positive and double-positive portions. CONCLUSIONS: Monochromatic color combinations can facilitate the visual evaluation of FDG-uptake and diffusivity as well as registration accuracy on the FDG-PET/DW fusion images, when red- and green-colored elements are assigned to FDG-PET and DW images, respectively.

DOI： 10.1007/s12149-018-1263-y

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: 4D dynamic MR angiography (4D-MRA) using pseudo-continuous arterial spin labeling (pCASL), combined with Keyhole and View-sharing (4D-PACK) for scan acceleration, is introduced. Its validity for arterial inflow dynamics visualization was investigated through comparison with 4D-pCASL and contrast inherent inflow enhanced multiphase angiography (CINEMA). METHODS: Six healthy volunteers were included in the study. The arterial transit time (ATT) in 4D-PACK was measured at multiple regions in middle cerebral artery (MCA), and Pearson's correlation coefficient with ATT in 4D-pCASL was calculated. The contrast-to-noise ratio (CNR) in 4D-PACK was measured in four MCA segments and compared with that in 4D-pCASL and CINEMA. Arterial visualization in 4D-PACK was assessed qualitatively in patients with moyamoya disease and arteriovenous malformation by comparing with CINEMA. RESULTS: 4D-PACK achieved a 36&#37; scan time reduction compared with 4D-pCASL. The correlation coefficient for ATT measured by 4D-pCASL and 4D-PACK was greater than 0.96. The CNR was significantly higher using 4D-PACK compared with CINEMA in the M4 segment (P < 0.01). In patient examinations, the flow in the collateral artery or draining vein was better visualized in 4D-PACK compared with CINEMA. CONCLUSION: 4D-PACK accelerates 4D-pCASL, shows similar inflow dynamics as 4D-pCASL and shows better peripheral visualization compared with CINEMA. Magn Reson Med 80:719-725, 2018. © 2018 International Society for Magnetic Resonance in Medicine.

DOI： 10.1002/mrm.27074

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objective: To investigate the optimal monochromatic color combination for fusion imaging of FDG-PET and diffusion-weighted MR images (DW) regarding lesion conspicuity of each image. Methods: Six linear monochromatic color-maps of red, blue, green, cyan, magenta, and yellow were assigned to each of the FDG-PET and DW images. Total perceptual color differences of the lesions were calculated based on the lightness and chromaticity measured with the photometer. Visual lesion conspicuity was also compared among the PET-only, DW-only and PET-DW-double positive portions with mean conspicuity scores. Statistical analysis was performed with a one-way analysis of variance and Spearman’s rank correlation coefficient. Results: Among all the 12 possible monochromatic color-map combinations, the 3 combinations of red/cyan, magenta/green, and red/green produced the highest conspicuity scores. Total color differences between PET-positive and double-positive portions correlated with conspicuity scores (ρ = 0.2933, p < 0.005). Lightness differences showed a significant negative correlation with conspicuity scores between the PET-only and DWI-only positive portions. Chromaticity differences showed a marginally significant correlation with conspicuity scores between DWI-positive and double-positive portions. Conclusions: Monochromatic color combinations can facilitate the visual evaluation of FDG-uptake and diffusivity as well as registration accuracy on the FDG-PET/DW fusion images, when red- and green-colored elements are assigned to FDG-PET and DW images, respectively.

DOI： 10.1007/s12149-018-1263-y

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND AND PURPOSE: Glycosaminoglycan chemical exchange saturation transfer (gagCEST) imaging allows the direct measurement and mapping of glycosaminoglycans. In this study, we aimed to evaluate the usefulness of gagCEST imaging in the quantitative assessment of intervertebral disc degeneration in a comparison with Pfirrmann grade and T1- measurements. MATERIALS AND METHODS: Ninety-six lumbar intervertebral discs in 24 volunteers (36.0 8.5 years of age, 21 men and 3 women) were examined with both gagCEST imaging and T1- measurements. The gagCEST imaging was performed at 3T with a saturation pulse with 1.0-second duration and the B₁ amplitude of 0.8 T followed by imaging by a 2D fast spin-echo sequence. The Z-spectra were obtained at 25 frequency offsets from 3 to 3 ppm (step, 0.25 ppm). A point-by-point B₀ correction was performed with a B₀ map. The gagCEST signal and T1- values were measured in the nucleus pulposus in each intervertebral disc. The Pfirrmann grades were assessed on T2-weighted images. RESULTS: The gagCEST signal at grade I (5.36% 2.79%) was significantly higher than those at Pfirrmann grade II (3.15% 1.40%, P .0006), grade III (0.14% 1.03%, P .0001), grade IV (1.75% 2.82%, P .0001), and grade V (1.47% 0.36%, P .0001). The gagCEST signal at grade II was significantly higher than those of grade III (P .0001), grade IV (P .0001), and grade V (P .0001). The gagCEST signal was significantly correlated negatively with Pfirrmann grade (P .0001) and positively correlated with T1- (P .0001). CONCLUSIONS: GagCEST imaging could be a reliable and quantitative technique for assessing intervertebral disc degeneration.

DOI： 10.3174/ajnr.A5657

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: The purpose of this study was to correlate diffusivity of extraocular muscles, measured by three-dimensional turbo field echo (3DTFE) magnetic resonance (MR) imaging using diffusion-sensitized driven-equilibrium preparation, with their size and activity in patients with Grave's ophthalmopathy. Materials and methods: Twenty-three patients with Grave's ophthalmopathy were included. There were 17 women and 6 men with a mean age of 55.8 ± 12.6 (SD) years (range: 26–83 years). 3DTFE with diffusion-sensitized driven-equilibrium MR images were obtained with b-values of 0 and 500 s/mm². The apparent diffusion coefficient (ADC) of extraocular muscles was measured on coronal reformatted MR images. Signal intensities of extraocular muscles on conventional MR images were compared to those of normal-appearing white matter, and cross-sectional areas of the muscles were also measured. The clinical activity score was also evaluated. Statistical analyses were performed with Pearson correlation and Mann-Whitney U tests. Results: On 3DTFE with diffusion-sensitized driven-equilibrium preparation, the mean ADC of the extraocular muscles was 2.23 ± 0.37 (SD) × 10⁻³ mm2/s (range: 1.70 × 10⁻³–3.11 × 10⁻³ mm²/s). There was a statistically significant moderate correlation between ADC and the size of the muscles (r = 0.61). There were no statistically significant correlations between ADC and signal intensity on conventional MR and the clinical activity score. Conclusion: 3DTFE with diffusion-sensitized driven-equilibrium preparation technique allows quantifying diffusivity of extraocular muscles in patients with Grave's ophthalmopathy. The diffusivity of the extraocular muscles on 3DTFE with diffusion-sensitized driven-equilibrium preparation MR images moderately correlates with their size.

DOI： 10.1016/j.diii.2018.02.007

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Background Hoarding disorder (HD) is a disease concept newly presented in DSM-5. As far as we know, no studies have examined the structural changes relevant to hoarding by applying the diagnostic criteria of HD in DSM-5. In the present study, we aimed to find abnormalities in gray matter (GM) structures of patients with HD. Methods Seventeen patients who met the DSM-5 criteria for HD, 17 obsessive-compulsive disorder (OCD) patients, and 17 healthy controls (HCs) participated in this study. All participants underwent MRI scanning of the brain by a 3.0-Tesla MRI scanner. In a voxel-based morphometric procedure, preprocessed GM structural images were used to compare the three groups. Thereafter we investigated the correlation between the clinical data (age of onset, symptomatic severity) and GM volume. Results The HD group showed a significantly increased GM volume compared to the OCD and healthy control groups (p<0.05) in both Brodmann area (BA)10 and BA11. There was no significant difference between OCD and healthy control groups. No significant correlation between the clinical data including age of onset, symptom severity score, and GM volume was observed in HD and OCD groups. Conclusions The results might help to explain the inconsistency of previous studies. As with OCD, HD is considered to have cognitive dysfunction as its basis. This result is convincing after considering the clinical features of HD and suggested that structural abnormalities in the prefrontal regions might relate to the pathophysiology of HD.

DOI： 10.1371/journal.pone.0200814

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To differentiate cystic from solid solitary intraorbital tumors using 3D turbo field echo with diffusion-sensitized driven-equilibrium preparation without contrast material. Materials and Methods: This retrospective study was approved by our institutional review boards, and written informed consent was waived. A total of 26 patients with intraorbital tumors were studied. Motion probing gradients were conducted at one direction with b‑values of 0 and 500 s/mm². The voxel size was 1.5 × 1.5 × 1.5 mm³, and acquisition time was 5 min 22 s. Additionally, fat-suppressed T2-weighted imaging (T2WI) and T1WI were obtained. The apparent diffusion coefficients (ADC) of the lesions were measured. Signal intensity on conventional magnetic resonance imaging (MRI) compared to normal appearing white matter was also measured. Statistical analysis was performed with Mann-Whitney U-test, the Steel-Dwass test and the receiver operating characteristic (ROC) analysis. Results: There were 10 cystic (7 dermoids, 2 epidermoids, and 1 cystadenoma) and 16 solid (8 cavernous hemangiomas, 6 pleomorphic adenomas, 1 adenocarcinoma, and 1 sebaceous carcinoma) tumors. The ADC of the cystic tumors (mean ± SD; 2.21 ± 0.76 × 10⁻³ mm²/s) was statistically significantly lower than that of solid tumors (1.43 ± 0.41 × 10⁻³ mm²/s; P < 0.05).; however, there were no statistically significant differences on conventional MRI (P > 0.05). There were no statistically significant differences among tumor subtypes in all parameters (P > 0.05). The ROC analysis showed the best diagnostic performance with ADC (Az = 0.77). Conclusion: With its insensitivity to field inhomogeneity and high spatial resolution, the 3D DSDE-TFE technique enabled us to discriminate cystic tumors from solid tumors.

DOI： 10.1007/s00062-016-0556-6

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To differentiate cystic from solid solitary intraorbital tumors using 3D turbo field echo with diffusion-sensitized driven-equilibrium preparation without contrast material. MATERIALS AND METHODS: This retrospective study was approved by our institutional review boards, and written informed consent was waived. A total of 26 patients with intraorbital tumors were studied. Motion probing gradients were conducted at one direction with b‑values of 0 and 500 s/mm2. The voxel size was 1.5 × 1.5 × 1.5 mm3, and acquisition time was 5 min 22 s. Additionally, fat-suppressed T2-weighted imaging (T2WI) and T1WI were obtained. The apparent diffusion coefficients (ADC) of the lesions were measured. Signal intensity on conventional magnetic resonance imaging (MRI) compared to normal appearing white matter was also measured. Statistical analysis was performed with Mann-Whitney U-test, the Steel-Dwass test and the receiver operating characteristic (ROC) analysis. RESULTS: There were 10 cystic (7 dermoids, 2 epidermoids, and 1 cystadenoma) and 16 solid (8 cavernous hemangiomas, 6 pleomorphic adenomas, 1 adenocarcinoma, and 1 sebaceous carcinoma) tumors. The ADC of the cystic tumors (mean ± SD; 2.21 ± 0.76 × 10-3 mm2/s) was statistically significantly lower than that of solid tumors (1.43 ± 0.41 × 10-3 mm2/s; P < 0.05).; however, there were no statistically significant differences on conventional MRI (P > 0.05). There were no statistically significant differences among tumor subtypes in all parameters (P > 0.05). The ROC analysis showed the best diagnostic performance with ADC (Az = 0.77). CONCLUSION: With its insensitivity to field inhomogeneity and high spatial resolution, the 3D DSDE-TFE technique enabled us to discriminate cystic tumors from solid tumors.

DOI： 10.1007/s00062-016-0556-6

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Cortical lesions (CLs) frequently observed in Caucasian patients with multiple sclerosis (MS) contribute to disability. However, it remains unclear whether CLs are associated with clinical features and genetic risk factors, such as HLA-DRB1*15:01 and -DRB1*04:05 in Asian MS patients. OBJECTIVE: To elucidate the frequency of CLs and their association with HLA-DRB1 and DPB1 alleles in Japanese MS patients. METHODS: Three-dimensional double inversion recovery imaging and clinical information were retrospectively obtained from 92 Japanese MS patients. RESULTS: CLs of any type, intracortical lesions (ICLs), and leukocortical lesions (LCLs) were detected in 39.1&#37;, 26.1&#37;, and 28.3&#37; of patients, respectively. MS patients with ICLs had a significantly higher frequency of secondary progression and greater Expanded Disability Status Scale (EDSS) scores than those without ICLs. Similar trends were observed with CLs and LCLs. The number of all three lesion types positively correlated with EDSS scores. The frequency and number of ICLs were significantly higher in HLA-DRB1*15:01 carriers than in HLA-DRB1*15:01 non-carriers, but significantly lower in HLA-DRB1*04:05 carriers than in HLA-DRB1*04:05 non-carriers. Multivariate logistic regression analysis revealed a negative association of HLA-DRB1*04:05 with ICLs. CONCLUSION: ICLs are associated with greater disease severity in Japanese MS patients and are partly suppressed by the HLA-DRB1*04:05 allele.

DOI： 10.1177/1352458517707067

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: To evaluate the quantification performance of the perfusion fraction (f) measured with intravoxel incoherent motion (IVIM) MR imaging in a comparison with the histological vascular density in meningiomas. METHODS: 29 consecutive patients with meningioma (59.0 ± 16.8 years old, 8 males and 21 females) who underwent a subsequent surgical resection were examined with both IVIM imaging and a histopathological analysis. IVIM imaging was conducted using a single-shot SE-EPI sequence with 13 b-factors (0, 10, 20, 30, 50, 80, 100, 200, 300, 400, 600, 800, 1000 s mm-2) at 3T. The perfusion fraction (f) was calculated by fitting the IVIM bi-exponential model. The 90-percentile f-value in the tumor region-of-interest (ROI) was defined as the maximum f-value (f-max). Histopathological vascular density (&#37;Vessel) was measured on CD31-immunostainted histopathological specimens. The correlation and agreement between the f-values and &#37;Vessel was assessed. RESULTS: The f-max (15.5 ± 5.5&#37;) showed excellent agreement [intraclass correlation coefficient (ICC) = 0.754] and a significant correlation (r = 0.69, p < 0.0001) with the &#37;Vessel (12.9 ± 9.4&#37;) of the tumors. The Bland-Altman plot analysis showed excellent agreement between the f-max and &#37;Vessel (bias, -2.6&#37;; 95&#37; limits of agreement, from -16.0 to 10.8&#37;). The f-max was not significantly different among the histological subtypes of meningioma. CONCLUSION: An excellent agreement and a significant correlation were observed between the f-values and &#37;Vessel. The f-value can be used as a noninvasive quantitative imaging measure to directly assess the vascular volume fraction in brain tumors. Advances in knowledge: The f-value measured by IVIM imaging showed a significant correlation and an excellent agreement with the histological vascular density in the meningiomas. The f-value can be used as a noninvasive and quantitative imaging measure to directly assess the volume fraction of capillaries in brain tumors.

DOI： 10.1259/bjr.20170912

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: Imaging findings of pilocytic astrocytoma (PA) vary widely, sometimes resembling those of high-grade glioma (HGG). This study aimed to identify the imaging parameters that can be used to differentiate PA from HGG. Methods: Altogether, 60 patients with PAs and 138 patients with HGGs were included in the study. Tumor properties and the presence of hydrocephalus, peritumoral edema, and dissemination were evaluated. We also measured the maximum relative cerebral blood flow (rCBF_max) and volume (rCBV_max) and determined the minimum apparent diffusion coefficient (ADC_min) in the tumor’s solid components. The relative T1 (rT1), T2 (rT2), and contrast-enhanced T1 (rCE-T1) intensity values were evaluated. Parameters were compared between PAs and HGGs using the Mann–Whitney U test. Receiver operating characteristic (ROC) curve analysis was also used to evaluate these imaging parameters. A value of P <.05 was considered to indicate significance. Results: Intratumoral hemorrhage and calcification were observed in 10.0% and 21.7% of PAs, respectively. The rCBF_max and rCBV_max values were significantly lower in PAs (0.50 ± 0.35, 1.82 ± 1.21) than those in HGGs (2.98 ± 1.80, 9.54 ± 6.88) (P <.0001, P =.0002, respectively). The ADC_min values were significantly higher in PAs (1.36 ± 0.56 × 10⁻³ mm²/s) than those in HGGs (0.86 ± 0.37 × 10⁻³ mm²/s) (P <.0001). ROC analysis showed that the best diagnostic performance was achieved with rCBF_max. Conclusion: The rCBF_max, rCBV_max, and ADC_min can differentiate PAs from HGGs.

DOI： 10.1007/s00234-018-1991-7

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: Imaging findings of pilocytic astrocytoma (PA) vary widely, sometimes resembling those of high-grade glioma (HGG). This study aimed to identify the imaging parameters that can be used to differentiate PA from HGG. METHODS: Altogether, 60 patients with PAs and 138 patients with HGGs were included in the study. Tumor properties and the presence of hydrocephalus, peritumoral edema, and dissemination were evaluated. We also measured the maximum relative cerebral blood flow (rCBFmax) and volume (rCBVmax) and determined the minimum apparent diffusion coefficient (ADCmin) in the tumor's solid components. The relative T1 (rT1), T2 (rT2), and contrast-enhanced T1 (rCE-T1) intensity values were evaluated. Parameters were compared between PAs and HGGs using the Mann-Whitney U test. Receiver operating characteristic (ROC) curve analysis was also used to evaluate these imaging parameters. A value of P < .05 was considered to indicate significance. RESULTS: Intratumoral hemorrhage and calcification were observed in 10.0&#37; and 21.7&#37; of PAs, respectively. The rCBFmax and rCBVmax values were significantly lower in PAs (0.50 ± 0.35, 1.82 ± 1.21) than those in HGGs (2.98 ± 1.80, 9.54 ± 6.88) (P < .0001, P = .0002, respectively). The ADCmin values were significantly higher in PAs (1.36 ± 0.56 × 10-3 mm2/s) than those in HGGs (0.86 ± 0.37 × 10-3 mm2/s) (P < .0001). ROC analysis showed that the best diagnostic performance was achieved with rCBFmax. CONCLUSION: The rCBFmax, rCBVmax, and ADCmin can differentiate PAs from HGGs.

DOI： 10.1007/s00234-018-1991-7

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To evaluate the utility of amide proton transfer (APT) imaging in estimating histologic grades of endometrioid endometrial adenocarcinoma (EEA). Materials and The institutional review board approved this prospective Methods: study. Between June 2012 and March 2016, 32 patients with EEA underwent magnetic resonance (MR) imaging. After their surgical procedures, their EEAs were confirmed pathologically and classified into histologic grades: grade 1 (n = 11), grade 2 (n = 11), and grade 3 (n = 10). The APT signal intensities (SIs) and the mean and minimum apparent diffusion coefficients (ADCs) of the three grades were calculated and compared. Spearman rank correlation coefficient was also calculated between the APT SIs and histologic grades, and between the ADCs and histologic grades. Results: The Spearman correlation coefficient with histologic grade of the APT SIs, the mean ADC, and the minimum ADC were 0.55 (P = .001), 0.03 (P = .84), and 20.30 (P = .09), respectively. The average APT SIs and the mean and minimum ADCs were 2.2% 6 0.2 (standard deviation), 0.9 3 102³ mm²/sec 6 0.2, and 0.6 3 102³ mm²/sec 6 0.1 for grade 1; 3.2% 6 0.3, 0.8 3 102³ mm²/sec 6 0.1, and 0.5 3 102³ mm²/sec 6 0.1 for grade 2; and 3.7% 6 0.3, 0.9 3 102³ mm²/sec 6 0.1, and 0.5 3 102³ mm²/sec 6 0.1 for grade 3, respectively. The APT SIs of grade 3 EEA were significantly higher than those of grade 1 EEA (P = .01), but other pairwise comparisons did not reveal any significant differences (P = .06-.51). The mean and minimum ADCs showed no significant differences among the three histologic grades (P =.13-.51). Conclusion: The APT SI was positively correlated with the histologic grades of EEA.

DOI： 10.1148/radiol.2017170349

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Advance in the exome-wide sequencing analysis contributes to identifying hundreds of genes that are associated with early-onset epileptic encephalopathy and neurodevelopmental disorders. On the basis of massive sequencing data, functional interactions among different genes are suggested to explain the common molecular pathway underlying the pathogenic process of these disorders. However, the relevance of such interactions with the phenotypic severity or variety in an affected individual remains elusive. In this report, we present a 45-year-old woman with neurofibromatosis type 1 (NF1), infantile-onset epileptic encephalopathy, and severe developmental delay. Whole-exome sequencing identified de novo pathogenic mutations in NF1 and the Schaaf-Yang syndrome-associated gene, MAGEL2. Literature-curated interaction data predicted that NF1 and MAGEL2 proteins were closely connected in this network via their common interacting proteins. Direct conversion of fibroblasts into neurons in vitro showed that neuronal cells from 9 patients with NF1 expressed significantly lower levels of MAGEL2 (54&#37;, p = 0.0047) than those from healthy individuals. These data provide the first evidence that pathogenic mutations of NF1 deregulate the expression of other neurodevelopmental disease-associated genes. De novo mutations in multiple genes may lead to severe developmental phenotypes through their cumulative effects or synergistic interactions.

DOI： 10.1002/epi4.12085

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose To evaluate the utility of amide proton transfer (APT) imaging in estimating histologic grades of endometrioid endometrial adenocarcinoma (EEA). Materials and Methods The institutional review board approved this prospective study. Between June 2012 and March 2016, 32 patients with EEA underwent magnetic resonance (MR) imaging. After their surgical procedures, their EEAs were confirmed pathologically and classified into histologic grades: grade 1 (n = 11), grade 2 (n = 11), and grade 3 (n = 10). The APT signal intensities (SIs) and the mean and minimum apparent diffusion coefficients (ADCs) of the three grades were calculated and compared. Spearman rank correlation coefficient was also calculated between the APT SIs and histologic grades, and between the ADCs and histologic grades. Results The Spearman correlation coefficient with histologic grade of the APT SIs, the mean ADC, and the minimum ADC were 0.55 (P = .001), 0.03 (P = .84), and -0.30 (P = .09), respectively. The average APT SIs and the mean and minimum ADCs were 2.2&#37; ± 0.2 (standard deviation), 0.9 × 10-3 mm2/sec ± 0.2, and 0.6 × 10-3 mm2/sec ± 0.1 for grade 1; 3.2&#37; ± 0.3, 0.8 × 10-3 mm2/sec ± 0.1, and 0.5 × 10-3 mm2/sec ± 0.1 for grade 2; and 3.7&#37; ± 0.3, 0.9 × 10-3 mm2/sec ± 0.1, and 0.5 × 10-3 mm2/sec ± 0.1 for grade 3, respectively. The APT SIs of grade 3 EEA were significantly higher than those of grade 1 EEA (P = .01), but other pairwise comparisons did not reveal any significant differences (P = .06-.51). The mean and minimum ADCs showed no significant differences among the three histologic grades (P =.13-.51). Conclusion The APT SI was positively correlated with the histologic grades of EEA. © RSNA, 2017 Online supplemental material is available for this article.

DOI： 10.1148/radiol.2017170349

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To evaluate and compare the performance of accelerationselective arterial spin labeling (AccASL) magnetic resonance (MR) angiography in the visualization of cerebral arteries and collateral vessels in patients with Moyamoya disease with that of time-of-flight (TOF) MR angiography, with digital subtraction angiography (DSA) as the reference standard. Materials and Methods: Thirty-six cerebral hemispheres from 22 patients with Moyamoya disease underwent TOF and AccASL MR angiography and DSA. Qualitative evaluations included imaging of the terminal internal carotid artery (ICA), distal middle cerebral arteries (MCAs), Moyamoya vessels, and leptomeningeal anastomosis (LMA) collaterals with reference to DSA. Quantitative evaluations included assessment of contrast-tonoise ratio (CNR) and number of vessels in MCA branches. The linear mixed-effect model was used to compare the two methods. Results: Mean scores for qualitative evaluation were significantly higher with AccASL angiography than with TOF angiography for imaging distal MCAs (3.9 6 0.3 [standard deviation] vs 2.9 6 1.1; P , .001), Moyamoya vessels (3.6 6 0.6 vs 2.7 6 0.9, P , .001), and LMA collaterals (3.8 6 0.6 vs 1.8 6 0.7, P , .001). Scores for steno-occlusive degree around the terminal ICAs were better with TOF angiography than with AccASL angiography (2.6 6 0.5 vs 2.4 6 0.6, P = .023). CNRs in the M4 segment were significantly higher with AccASL angiography (11.9 6 12.9, P , .001) than with TOF angiography (4.1 6 7.9). The number of vessels was significantly higher with AccASL angiography (18.3 6 5.0, P , .001) than with TOF angiography (8.9 6 4.9). The increase in the number of vessels from TOF angiography to AccASL angiography was greater in patients with severe ICA stenoocclusion (late ICA stage group, 11.4 6 4.5; early ICA stage group, 6.8 6 4.0; P = .007) and well-developed leptomeningeal anastomosis (mildly developed LMA group, 7.1 6 4.3; well-developed LMA group, 11.3 6 4.5; P = .011). Conclusion: AccASL MR angiography enables better visualization of distal cerebral arteries and collateral vessels in patients with Moyamoya disease than does TOF MR angiography, while TOF MR angiography enables better visualization of stenosis of proximal arteries. Both methods work in a mutually beneficial manner in the assessment of cerebral arteries.

DOI： 10.1148/radiol.2017162279

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose To evaluate and compare the performance of acceleration-selective arterial spin labeling (AccASL) magnetic resonance (MR) angiography in the visualization of cerebral arteries and collateral vessels in patients with Moyamoya disease with that of time-of-flight (TOF) MR angiography, with digital subtraction angiography (DSA) as the reference standard. Materials and Methods Thirty-six cerebral hemispheres from 22 patients with Moyamoya disease underwent TOF and AccASL MR angiography and DSA. Qualitative evaluations included imaging of the terminal internal carotid artery (ICA), distal middle cerebral arteries (MCAs), Moyamoya vessels, and leptomeningeal anastomosis (LMA) collaterals with reference to DSA. Quantitative evaluations included assessment of contrast-to-noise ratio (CNR) and number of vessels in MCA branches. The linear mixed-effect model was used to compare the two methods. Results Mean scores for qualitative evaluation were significantly higher with AccASL angiography than with TOF angiography for imaging distal MCAs (3.9 ± 0.3 [standard deviation] vs 2.9 ± 1.1; P < .001), Moyamoya vessels (3.6 ± 0.6 vs 2.7 ± 0.9, P < .001), and LMA collaterals (3.8 ± 0.6 vs 1.8 ± 0.7, P < .001). Scores for steno-occlusive degree around the terminal ICAs were better with TOF angiography than with AccASL angiography (2.6 ± 0.5 vs 2.4 ± 0.6, P = .023). CNRs in the M4 segment were significantly higher with AccASL angiography (11.9 ± 12.9, P < .001) than with TOF angiography (4.1 ± 7.9). The number of vessels was significantly higher with AccASL angiography (18.3 ± 5.0, P < .001) than with TOF angiography (8.9 ± 4.9). The increase in the number of vessels from TOF angiography to AccASL angiography was greater in patients with severe ICA steno-occlusion (late ICA stage group, 11.4 ± 4.5; early ICA stage group, 6.8 ± 4.0; P = .007) and well-developed leptomeningeal anastomosis (mildly developed LMA group, 7.1 ± 4.3; well-developed LMA group, 11.3 ± 4.5; P = .011). Conclusion AccASL MR angiography enables better visualization of distal cerebral arteries and collateral vessels in patients with Moyamoya disease than does TOF MR angiography, while TOF MR angiography enables better visualization of stenosis of proximal arteries. Both methods work in a mutually beneficial manner in the assessment of cerebral arteries. © RSNA, 2017 Online supplemental material is available for this article.

DOI： 10.1148/radiol.2017162279

記述言語：英語   掲載種別：研究論文（学術雑誌）  

We regret that Table 1 and Fig. 2 need correction. As for Table 1, we found a few critical errors. The patients' age is not 18–64 years old, correctly 17–64 years old. The patients' age of onset is not 4–38 years old, correctly 6–54 years old. The patients' duration of illness is not 0.6–42 years, correctly 0.6–51 years. As for Fig.2, several readers pointed us that it was difficult to see. So we would like to make corrections. We coloured the lines to make it distinguishable, and enlarged letters to make it more visible. We explained in footnote which line colour corresponds to which group. We attached the modified files. We are sorry to trouble you, but we hope that you will correct and replace them by the following files. We would like to apologise for any inconvenience caused.

DOI： 10.1016/j.jocrd.2017.11.005

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To compare the abilities of turbo spin-echo diffusion-weighted imaging (TSE DWI) and multi-shot echo planar DWI (MSh DWI) to discriminate orbital lymphoma from inflammatory lesions. MATERIALS AND METHODS: Twenty-nine patients with pathologically confirmed lymphomas and 39 patients with inflammation were imaged with a 3.0-T system. The apparent diffusion coefficient (ADC) of each lesion was measured. Signal intensities compared to normal grey matter on conventional imaging were also measured. RESULTS: The ADCs derived from the TSE DWI of the lymphomas (0.68 ± 0.14 × 10-3 mm2/s) were significantly lower than those of the inflammation cases (1.04 ± 0.39 × 10-3 mm2/s; p < 0.001). The ADCs derived from MSh DWI could not be used to separate the lymphomas from the inflammation (1.16 ± 0.43 × 10-3 mm2/s vs. 1.36 ± 0.48 × 10-3 mm2/s; p = 0.06). Conventional sequences also could not separate the lymphomas from the inflammation (p > 0.05). The ROC analysis showed the best diagnostic performance with ADCs derived from TSE DWI (the area under the curve: AUC = 0.831) followed by ADC derived from MSh DWI (AUC = 0.633). CONCLUSION: The ADCs derived from TSE DWI might help to differentiate orbital lymphomas from inflammation. KEY POINTS: • ADC of lymphoma was significantly lower than that of inflammation. • ADC derived from TSE DWI showed the best diagnostic performance. • This study was conducted by a 3-T MR scanner.

DOI： 10.1007/s00330-017-4995-5

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objective: To evaluate the quantification performance of the perfusion fraction (f) measured with intravoxel incoherent motion (IVIM) MR imaging in a comparison with the histological vascular density in meningiomas. Methods: 29 consecutive patients with meningioma (59.0 ± 16.8 years old, 8 males and 21 females) who underwent a subsequent surgical resection were examined with both IVIM imaging and a histopathological analysis. IVIM imaging was conducted using a singleshot SE-EPI sequence with 13 b-factors (0, 10, 20, 30, 50, 80, 100, 200, 300, 400, 600, 800, 1000 s mm-2) at 3T. The perfusion fraction (f) was calculated by fitting the IVIM bi-exponential model. The 90-percentile f-value in the tumor region-of-interest (ROI) was defined as the maximum f-value (f-max). Histopathological vascular density (%Vessel) was measured on CD31-immunostainted histopathological specimens. The correlation and agreement between the f-values and %Vessel was assessed. Results: The f-max (15.5 ± 5.5%) showed excellent agreement [intraclass correlation coefficient (ICC) = 0.754] and a significant correlation (r = 0.69, p < 0.0001) with the %Vessel (12.9 ± 9.4%) of the tumors. The Bland- Altman plot analysis showed excellent agreement between the f-max and %Vessel (bias, -2.6%; 95% limits of agreement, from -16.0 to 10.8%). The f-max was not significantly different among the histological subtypes of meningioma. Conclusion: An excellent agreement and a significant correlation were observed between the f-values and %Vessel. The f-value can be used as a noninvasive quantitative imaging measure to directly assess the vascular volume fraction in brain tumors. Advances in knowledge: The f-value measured by IVIM imaging showed a significant correlation and an excellent agreement with the histological vascular density in the meningiomas. The f-value can be used as a noninvasive and quantitative imaging measure to directly assess the volume fraction of capillaries in brain tumors.

DOI： 10.1259/bjr.20170912

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objective: To evaluate the usefulness of simultaneous T₂ mapping and neurography with nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation enhancement imaging (SHINKEI) in the lumbar plexus to distinguish patients with chronic inflammatory demyelinating polyneuropathy (CIDP) from healthy controls. Methods: Our institutional review boards approved this retrospective study, and written informed consent was waived. 10 patients with CIDP from 2015 to 2017 were studied along with 5 healthy controls on a 3 T scanner. The T₂ relaxation time and the size of the dorsal root ganglia and nerves of the lumbar plexus at L3-S1 were measured. Statistical analyses were performed with the Mann-Whitney U test and a receiver operating characteristics analysis. Results: The T₂ relaxation times of the dorsal root ganglia and the nerves of the lumbar plexus were longer in the CIDP patients (133.34 ± 41.36 and 130.40 ± 47.78 ms) compared to the healthy controls (114.69 ± 24.90 and 83.72 ± 17.51 ms, p = 0.0265 andp < 0.0001, respectively). The sizes of the nerves were larger in the CIDP patients (6.19 ± 2.28 mm) compared to the controls (4.54 ± 0.86 mm, p < 0.0001). However, there was no significant difference between the sizes of the ganglia in the CIDP patients and the controls. The receiver operating characteristics analysis revealed that the T₂ relaxation time of the nerves was best at distinguishing the CIDP patients from the controls (Az = 0.848). Conclusion: Patients with CIDP could be distinguished from healthy controls using simultaneous T₂ mapping and neurography with SHINKEI in the lumbar plexus. Advances in knowledge: Patients with CIDP could be distinguished from healthy controls using simultaneous T₂ mapping and neurography with SHINKEI in the lumbar plexus.

DOI： 10.1259/bjr.20180501

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Advance in the exome-wide sequencing analysis contributes to identifying hundreds of genes that are associated with early-onset epileptic encephalopathy and neurodevelopmental disorders. On the basis of massive sequencing data, functional interactions among different genes are suggested to explain the common molecular pathway underlying the pathogenic process of these disorders. However, the relevance of such interactions with the phenotypic severity or variety in an affected individual remains elusive. In this report, we present a 45-year-old woman with neurofibromatosis type 1 (NF1), infantile-onset epileptic encephalopathy, and severe developmental delay. Whole-exome sequencing identified de novo pathogenic mutations in NF1 and the Schaaf-Yang syndrome-associated gene, MAGEL2. Literature-curated interaction data predicted that NF1 and MAGEL2 proteins were closely connected in this network via their common interacting proteins. Direct conversion of fibroblasts into neurons in vitro showed that neuronal cells from 9 patients with NF1 expressed significantly lower levels of MAGEL2 (54%, p = 0.0047) than those from healthy individuals. These data provide the first evidence that pathogenic mutations of NF1 deregulate the expression of other neurodevelopmental disease-associated genes. De novo mutations in multiple genes may lead to severe developmental phenotypes through their cumulative effects or synergistic interactions.

DOI： 10.1002/epi4.12085

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To compare the abilities of turbo spin-echo diffusion-weighted imaging (TSE DWI) and multi-shot echo planar DWI (MSh DWI) to discriminate orbital lymphoma from inflammatory lesions. Materials and methods: Twenty-nine patients with pathologically confirmed lymphomas and 39 patients with inflammation were imaged with a 3.0-T system. The apparent diffusion coefficient (ADC) of each lesion was measured. Signal intensities compared to normal grey matter on conventional imaging were also measured. Results: The ADCs derived from the TSE DWI of the lymphomas (0.68 ± 0.14 × 10⁻³ mm²/s) were significantly lower than those of the inflammation cases (1.04 ± 0.39 × 10⁻³ mm²/s; p < 0.001). The ADCs derived from MSh DWI could not be used to separate the lymphomas from the inflammation (1.16 ± 0.43 × 10⁻³ mm²/s vs. 1.36 ± 0.48 × 10⁻³ mm²/s; p = 0.06). Conventional sequences also could not separate the lymphomas from the inflammation (p > 0.05). The ROC analysis showed the best diagnostic performance with ADCs derived from TSE DWI (the area under the curve: AUC = 0.831) followed by ADC derived from MSh DWI (AUC = 0.633). Conclusion: The ADCs derived from TSE DWI might help to differentiate orbital lymphomas from inflammation. Key Points: • ADC of lymphoma was significantly lower than that of inflammation. • ADC derived from TSE DWI showed the best diagnostic performance. • This study was conducted by a 3-T MR scanner.

DOI： 10.1007/s00330-017-4995-5

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Traditional MRI methods for estimation of blood flow in brain tumors require high-flow injection of contrast agents through large-bore intravenous access, which limits their pediatric utility. In contrast, arterial spin-labeling (ASL) can be used without contrast media. This study aimed to evaluate the relationship between tumor blood flow (TBF) measured by ASL and histopathological vascular density in pediatric brain tumors. Nineteen consecutive children were evaluated (10 boys, 9 girls; median age: 6 years; 8 high-grade and 11 low-grade tumors). ASL was performed with a pseudocontinuous labeling time of 1650 ms and post-labeling delay of 1525 ms. The maximal absolute (aTBF) and relative (rTBF) tumor blood flows were measured. To evaluate the relative vascular area (%Vessel), the total stained vascular area was divided by the whole tissue area. Spearman’s rank-order correlation, the Mann–Whitney U test, and receiver operating characteristic analysis were used for statistical analysis. The absolute and relative TBF rates were 4.9–92.9 mL/100 g/min and 0.17–3.59 mL/100 g/min, respectively. The %Vessel was 0.6–30.2%. The %Vessel showed a significant positive correlation with TBF (aTBF: r = 0.87, P < 0.0001; rTBF: r = 0.89, P < 0.0001). The TBF rate of high-grade tumors was significantly higher than that of low-grade tumors (aTBF: P = 0.0050, rTBF: P = 0.0036). The rTBF had the best diagnostic performance (area under the curve: 0.89). ASL perfusion imaging without contrast material can be used for accurate evaluation of histopathological vascular density and may be helpful for tumor grading in children.

DOI： 10.1007/s11060-017-2604-8

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: Patients with Parkinson's disease (PD) may exhibit symptoms of sympathetic dysfunction that can be measured using 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy. We investigated the relationship between microstructural brain changes and 123I-MIBG uptake in patients with PD using voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) analyses. METHODS: This retrospective study included 24 patients with PD who underwent 3 T magnetic resonance imaging and 123I-MIBG scintigraphy. They were divided into two groups: 12 MIBG-positive and 12 MIBG-negative cases (10 men and 14 women; age range: 60-81 years, corrected for gender and age). The heart/mediastinum count (H/M) ratio was calculated on anterior planar 123I-MIBG images obtained 4 h post-injection. VBM and DTI were performed to detect structural differences between these two groups. RESULTS: Patients with low H/M ratio had significantly reduced brain volume at the right inferior frontal gyrus (uncorrected p < 0.0001, K > 90). Patients with low H/M ratios also exhibited significantly lower fractional anisotropy than those with high H/M ratios (p < 0.05) at the left anterior thalamic radiation, the left inferior fronto-occipital fasciculus, the left superior longitudinal fasciculus, and the left uncinate fasciculus. CONCLUSIONS: VBM and DTI may reveal microstructural changes related to the degree of 123I-MIBG uptake in patients with PD. KEY POINTS: • Advanced MRI methods may detect brain damage more precisely. • Voxel-based morphometry can detect grey matter changes in Parkinson's disease. • Diffusion tensor imaging can detect white matter changes in Parkinson's disease.

DOI： 10.1007/s00330-017-4941-6

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Traditional MRI methods for estimation of blood flow in brain tumors require high-flow injection of contrast agents through large-bore intravenous access, which limits their pediatric utility. In contrast, arterial spin-labeling (ASL) can be used without contrast media. This study aimed to evaluate the relationship between tumor blood flow (TBF) measured by ASL and histopathological vascular density in pediatric brain tumors. Nineteen consecutive children were evaluated (10 boys, 9 girls; median age: 6 years; 8 high-grade and 11 low-grade tumors). ASL was performed with a pseudocontinuous labeling time of 1650 ms and post-labeling delay of 1525 ms. The maximal absolute (aTBF) and relative (rTBF) tumor blood flows were measured. To evaluate the relative vascular area (&#37;Vessel), the total stained vascular area was divided by the whole tissue area. Spearman's rank-order correlation, the Mann-Whitney U test, and receiver operating characteristic analysis were used for statistical analysis. The absolute and relative TBF rates were 4.9-92.9 mL/100 g/min and 0.17-3.59 mL/100 g/min, respectively. The &#37;Vessel was 0.6-30.2&#37;. The &#37;Vessel showed a significant positive correlation with TBF (aTBF: r = 0.87, P < 0.0001; rTBF: r = 0.89, P < 0.0001). The TBF rate of high-grade tumors was significantly higher than that of low-grade tumors (aTBF: P = 0.0050, rTBF: P = 0.0036). The rTBF had the best diagnostic performance (area under the curve: 0.89). ASL perfusion imaging without contrast material can be used for accurate evaluation of histopathological vascular density and may be helpful for tumor grading in children.

DOI： 10.1007/s11060-017-2604-8

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objective: Patients with Parkinson’s disease (PD) may exhibit symptoms of sympathetic dysfunction that can be measured using ¹²³I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy. We investigated the relationship between microstructural brain changes and ¹²³I-MIBG uptake in patients with PD using voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) analyses. Methods: This retrospective study included 24 patients with PD who underwent 3 T magnetic resonance imaging and ¹²³I-MIBG scintigraphy. They were divided into two groups: 12 MIBG-positive and 12 MIBG-negative cases (10 men and 14 women; age range: 60–81 years, corrected for gender and age). The heart/mediastinum count (H/M) ratio was calculated on anterior planar ¹²³I-MIBG images obtained 4 h post-injection. VBM and DTI were performed to detect structural differences between these two groups. Results: Patients with low H/M ratio had significantly reduced brain volume at the right inferior frontal gyrus (uncorrected p < 0.0001, K > 90). Patients with low H/M ratios also exhibited significantly lower fractional anisotropy than those with high H/M ratios (p < 0.05) at the left anterior thalamic radiation, the left inferior fronto-occipital fasciculus, the left superior longitudinal fasciculus, and the left uncinate fasciculus. Conclusions: VBM and DTI may reveal microstructural changes related to the degree of ¹²³I-MIBG uptake in patients with PD. Key Points: • Advanced MRI methods may detect brain damage more precisely. • Voxel-based morphometry can detect grey matter changes in Parkinson’s disease. • Diffusion tensor imaging can detect white matter changes in Parkinson’s disease.

DOI： 10.1007/s00330-017-4941-6

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Background Otosclerotic foci are usually seen as minute low-density lesions and this may be attributed to relatively low sensitivity on visual assessment using computed tomography (CT). Otosclerotic foci can be detected by using the accurate region of interest (ROI) setting, while small ROI settings by less-experienced radiologists may result in false negative findings. Purpose To evaluate the diagnostic ability of our proposed method ("otosclerosis-weighted" imaging [OWI]), which is based on reversing the density, compared with conventional CT (CCT) imaging alone. Material and Methods Temporal bone CTs of consecutive patients with otosclerosis were analyzed. Gender- and age-matched control participants were also included. All CT images were obtained using a 64-detector row scanner. OWI was obtained by extracting the temporal bone region using the threshold technique and reversing the density (black to white). Four independent radiologists took part in two reading sessions. In the first session, the observers read only CCT imaging. In the second session, they read OWI along with the CCT imaging. Sensitivity was assessed for the four readers. Results Thirty temporal bones of 25 patients with otosclerosis (3 men, 22 women; mean age, 53.9 ± 9.0 years) and 30 temporal bones of 30 control participants (4 men, 26 women; mean age, 44.0 ± 16.2 years) were included. For all observers, reading with a combination of the two methods was associated with a higher sensitivity (63.3-80.0%) than with conventional CT images alone (30.0-60.0%; P < 0.05, each). Conclusion Application of our proposed method based on threshold value may help detect foci of fenestral otosclerosis.

DOI： 10.1177/0284185116687172

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Background Otosclerotic foci are usually seen as minute low-density lesions and this may be attributed to relatively low sensitivity on visual assessment using computed tomography (CT). Otosclerotic foci can be detected by using the accurate region of interest (ROI) setting, while small ROI settings by less-experienced radiologists may result in false negative findings. Purpose To evaluate the diagnostic ability of our proposed method ("otosclerosis-weighted" imaging [OWI]), which is based on reversing the density, compared with conventional CT (CCT) imaging alone. Material and Methods Temporal bone CTs of consecutive patients with otosclerosis were analyzed. Gender- and age-matched control participants were also included. All CT images were obtained using a 64-detector row scanner. OWI was obtained by extracting the temporal bone region using the threshold technique and reversing the density (black to white). Four independent radiologists took part in two reading sessions. In the first session, the observers read only CCT imaging. In the second session, they read OWI along with the CCT imaging. Sensitivity was assessed for the four readers. Results Thirty temporal bones of 25 patients with otosclerosis (3 men, 22 women; mean age, 53.9 ± 9.0 years) and 30 temporal bones of 30 control participants (4 men, 26 women; mean age, 44.0 ± 16.2 years) were included. For all observers, reading with a combination of the two methods was associated with a higher sensitivity (63.3-80.0&#37;) than with conventional CT images alone (30.0-60.0&#37;; P < 0.05, each). Conclusion Application of our proposed method based on threshold value may help detect foci of fenestral otosclerosis.

DOI： 10.1177/0284185116687172

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose To evaluate whether 3D SHINKEI in the lumbar plexus could identify patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Materials and methods Twenty-one patients with CIDP and 15 non-CIDP patients were studied in this retrospective study. The SNR, contrast-to-noise ratio (CNR), contrast ratio (CR) and the size of the lumbar ganglions and roots were measured. Statistical analyses were performed with Mann-Whitney U test and receiver operating characteristics (ROC) analysis. Results The SNRs of the ganglions and roots were larger in patients with CIDP (8.30 ± 4.87 and 8.24 ± 4.92) than in non-CIDP patients (4.95 ± 2.05 and 5.08 ± 1.97, P < 0.0001, respectively). The CNRs of the ganglions and roots were larger in patients with CIDP (40.79 ± 43.19 and 37.16 ± 48.31) than in non-CIDP patients (25.90 ± 10.41 and 18.37 ± 32.83, P < 0.0001, respectively). The CRs of the ganglions and roots were larger in patients with CIDP (0.74 ± 0.13 and 0.66 ± 0.17) than in non-CIDP patients (0.72 ± 0.12 and 0.50 ± 0.17, P = 0.004 and P < 0.0001, respectively). The sizes of the ganglions and the roots were larger in patients with CIDP (6.62 ± 1.81 mm and 5.76 ± 3.24 mm) than in non-CIDP patients (5.23 ± 1.17 mm and 4.24 ± 1.11 mm, P < 0.0001, respectively). ROC analysis showed the best diagnostic performance with the CNR of the roots. Conclusion Patients with CIDP could be distinguished from controls on 3D SHINKEI.

DOI： 10.1016/j.ejrad.2017.05.031

記述言語：英語  

Spindle cell/sclerosing rhabdomyosarcoma (ssRMS) is a new subtype of rhabdomyosarcoma included in the World Health Organization soft tissue and bone tumor classification in 2013. Despite the increasing number of reported cases of ssRMS, the imaging characteristics of ssRMS are not established. Herein, we present the case of an elderly Japanese woman with ssRMS of the masticator space with intracranial invasion without destruction of the adjacent bone. Attention should be paid to the presence of intracranial infiltration that may indicate a worse prognosis. Tumor growth without bone destruction could be a key finding to differentiate ssRMSs from conventional subtypes of rhabdomyosarcoma.

DOI： 10.1177/2058460117727316

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To evaluate whether 3D SHINKEI in the lumbar plexus could identify patients with chronic inflammatory demyelinating polyneuropathy (CIDP). MATERIALS AND METHODS: Twenty-one patients with CIDP and 15 non-CIDP patients were studied in this retrospective study. The SNR, contrast-to-noise ratio (CNR), contrast ratio (CR) and the size of the lumbar ganglions and roots were measured. Statistical analyses were performed with Mann-Whitney U test and receiver operating characteristics (ROC) analysis. RESULTS: The SNRs of the ganglions and roots were larger in patients with CIDP (8.30±4.87 and 8.24±4.92) than in non-CIDP patients (4.95±2.05 and 5.08±1.97, P<0.0001, respectively). The CNRs of the ganglions and roots were larger in patients with CIDP (40.79±43.19 and 37.16±48.31) than in non-CIDP patients (25.90±10.41 and 18.37±32.83, P<0.0001, respectively). The CRs of the ganglions and roots were larger in patients with CIDP (0.74±0.13 and 0.66±0.17) than in non-CIDP patients (0.72±0.12 and 0.50±0.17, P=0.004 and P<0.0001, respectively). The sizes of the ganglions and the roots were larger in patients with CIDP (6.62±1.81mm and 5.76±3.24mm) than in non-CIDP patients (5.23±1.17mm and 4.24±1.11mm, P<0.0001, respectively). ROC analysis showed the best diagnostic performance with the CNR of the roots. CONCLUSION: Patients with CIDP could be distinguished from controls on 3D SHINKEI.

DOI： 10.1016/j.ejrad.2017.05.031

記述言語：英語   掲載種別：研究論文（学術雑誌）  

A recurrent glycine-to-arginine/valine alteration at codon 34 (G34R/V) within H3F3A, a gene that encodes the replication-independent histone variant H3.3, reportedly occurs exclusively in pediatric glioblastomas. However, the clinicopathological and biological significances of this mutation have not been completely elucidated; especially, no such data exist for tumor samples from Japanese patients. We analyzed 411 consecutive glioma cases representing patients of all ages. Our results demonstrated that 14 patients (3.4%) harbored H3F3A mutations, of which four had G34R mutations and 10 had K27M mutations. G34R-mutant tumors were located in the parietal region in two patients and the basal ganglia in one patient. One patient showed multi-lobular extension similar to the pattern observed in gliomatosis cerebri. Regarding neuroradiological features, intratumoral calcification was evident in two cases and all cases showed no or scarce contrast enhancement on MRI. Histopathologically, the four G34R-mutant cases included three glioblastomas and one astroblastoma. We have also investigated alterations in histone methylation including H3K27me3, H3K9me3, and H3K4me3 in G34R-mutant samples by immunohistochemistry. These results indicate that G34R-mutant tumors are likely to show extensive infiltration and alterations in global histone trimethylation might also play an important role in G34R mutant tumors.

DOI： 10.1007/s10014-017-0287-7

記述言語：英語   掲載種別：研究論文（学術雑誌）  

A recurrent glycine-to-arginine/valine alteration at codon 34 (G34R/V) within H3F3A, a gene that encodes the replication-independent histone variant H3.3, reportedly occurs exclusively in pediatric glioblastomas. However, the clinicopathological and biological significances of this mutation have not been completely elucidated; especially, no such data exist for tumor samples from Japanese patients. We analyzed 411 consecutive glioma cases representing patients of all ages. Our results demonstrated that 14 patients (3.4&#37;) harbored H3F3A mutations, of which four had G34R mutations and 10 had K27M mutations. G34R-mutant tumors were located in the parietal region in two patients and the basal ganglia in one patient. One patient showed multi-lobular extension similar to the pattern observed in gliomatosis cerebri. Regarding neuroradiological features, intratumoral calcification was evident in two cases and all cases showed no or scarce contrast enhancement on MRI. Histopathologically, the four G34R-mutant cases included three glioblastomas and one astroblastoma. We have also investigated alterations in histone methylation including H3K27me3, H3K9me3, and H3K4me3 in G34R-mutant samples by immunohistochemistry. These results indicate that G34R-mutant tumors are likely to show extensive infiltration and alterations in global histone trimethylation might also play an important role in G34R mutant tumors.

DOI： 10.1007/s10014-017-0287-7

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To assess the quantitative performance of three-dimensional (3D) fast spin-echo (FSE) Dixon amide proton transfer (APT) imaging of brain tumors compared with B₀ correction with separate mapping methods. Methods: Twenty-two patients with brain tumors (54.2 ± 18.7 years old, 12 males and 10 females) were scanned at 3 Tesla (T). Z-spectra were obtained at seven different frequency offsets at ±3.1 ppm, ± 3.5 ppm, ± 3.9 ppm, and −1560 ppm. The scan was repeated three times at +3.5 ppm with echo shifts for Dixon B₀ mapping. The APT image corrected by a three-point Dixon-type B₀ map from the same scan (3D-Dixon) or a separate B₀ map (2D-separate and 3D-separate), and an uncorrected APT image (3D-uncorrected) were generated. We compared the APT-weighted signals within a tumor obtained with each 3D method with those obtained with 2D-separate as a reference standard. Results: Excellent agreements and correlations with the 2D-separate were obtained by the 3D-Dixon method for both mean (ICC = 0.964, r = 0.93, P < 0.0001) and 90th-percentile (ICC = 0.972, r = 0.95, P < 0.0001) APT-weighted signals. These agreements and correlations for 3D-Dixon were better than those obtained by the 3D-uncorrected and 3D-separate methods. Conclusion: The 3D FSE Dixon APT method with intrinsic B₀ correction offers a quantitative performance that is similar to that of established two-dimensional (2D) methods. Magn Reson Med 77:2272–2279, 2017.

DOI： 10.1002/mrm.26322

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To evaluate cerebral blood flow (CBF) laterality derived from arterial spin labeling (ASL) in early-stage Parkinson's disease (PD) patients compared with those with advanced stages. MATERIALS AND METHODS: Thirty-eight patients with PD (21 patients in early stages, 17 patients in advanced stages) were retrospectively studied. The CBF maps derived from 3T ASL data were co-registered to the corresponding 3DT1WI using SPM 12 software. Caudate nucleus (CN), putamen (PT), globus pallidus (GP), and thalamus (TH) were manually traced on the representative axial slices of 3DT1WI. CBF of the CN, PT, GP, and TH was measured using corresponding pixels on the co-registered CBF maps. A laterality index (LI) was calculated as the ratio of the contralateral CBF to primary affected side CBF. Each LI was compared between early and advanced stages of PD using the Mann-Whitney U-test. The LIs were also compared between each stage of PD. RESULTS: In the CN, the LIs were significantly higher in early stages (mean LI ± SD, 95&#37; confidence interval = 1.06 ± 0.14, 1.00-1.13) than in advanced stages (0.94 ± 0.14, 0.87-1.01; P < 0.05). We also observed a tendency toward decreased LIs with disease severity (1.10 ± 0.14, 0.99-1.21 for Hoehn and Yahr stage I; 1.04 ± 0.14, 0.92-1.12 for stage II; 0.96 ± 0.11, 0.89-1.10 for stage III; 0.93 ± 0.17, 0.81-1.05 for stage IV). CONCLUSION: The evaluation of CBF laterality pattern in the CN using ASL may be useful for assessing the disease severity of PD patients. LEVEL OF EVIDENCE: 3 J. MAGN. RESON. IMAGING 2017;45:1821-1826.

DOI： 10.1002/jmri.25489

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To assess the quantitative performance of three-dimensional (3D) fast spin-echo (FSE) Dixon amide proton transfer (APT) imaging of brain tumors compared with B0 correction with separate mapping methods. METHODS: Twenty-two patients with brain tumors (54.2 ± 18.7 years old, 12 males and 10 females) were scanned at 3 Tesla (T). Z-spectra were obtained at seven different frequency offsets at ±3.1 ppm, ± 3.5 ppm, ± 3.9 ppm, and -1560 ppm. The scan was repeated three times at +3.5 ppm with echo shifts for Dixon B0 mapping. The APT image corrected by a three-point Dixon-type B0 map from the same scan (3D-Dixon) or a separate B0 map (2D-separate and 3D-separate), and an uncorrected APT image (3D-uncorrected) were generated. We compared the APT-weighted signals within a tumor obtained with each 3D method with those obtained with 2D-separate as a reference standard. RESULTS: Excellent agreements and correlations with the 2D-separate were obtained by the 3D-Dixon method for both mean (ICC = 0.964, r = 0.93, P < 0.0001) and 90th-percentile (ICC = 0.972, r = 0.95, P < 0.0001) APT-weighted signals. These agreements and correlations for 3D-Dixon were better than those obtained by the 3D-uncorrected and 3D-separate methods. CONCLUSION: The 3D FSE Dixon APT method with intrinsic B0 correction offers a quantitative performance that is similar to that of established two-dimensional (2D) methods. Magn Reson Med 77:2272-2279, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

DOI： 10.1002/mrm.26322

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To evaluate cerebral blood flow (CBF) laterality derived from arterial spin labeling (ASL) in early-stage Parkinson's disease (PD) patients compared with those with advanced stages. Materials and Methods: Thirty-eight patients with PD (21 patients in early stages, 17 patients in advanced stages) were retrospectively studied. The CBF maps derived from 3T ASL data were co-registered to the corresponding 3DT1WI using SPM 12 software. Caudate nucleus (CN), putamen (PT), globus pallidus (GP), and thalamus (TH) were manually traced on the representative axial slices of 3DT1WI. CBF of the CN, PT, GP, and TH was measured using corresponding pixels on the co-registered CBF maps. A laterality index (LI) was calculated as the ratio of the contralateral CBF to primary affected side CBF. Each LI was compared between early and advanced stages of PD using the Mann-Whitney U-test. The LIs were also compared between each stage of PD. Results: In the CN, the LIs were significantly higher in early stages (mean LI ± SD, 95% confidence interval = 1.06 ± 0.14, 1.00–1.13) than in advanced stages (0.94 ± 0.14, 0.87–1.01; P < 0.05). We also observed a tendency toward decreased LIs with disease severity (1.10 ± 0.14, 0.99–1.21 for Hoehn and Yahr stage I; 1.04 ± 0.14, 0.92–1.12 for stage II; 0.96 ± 0.11, 0.89–1.10 for stage III; 0.93 ± 0.17, 0.81–1.05 for stage IV). Conclusion: The evaluation of CBF laterality pattern in the CN using ASL may be useful for assessing the disease severity of PD patients. Level of Evidence: 3. J. MAGN. RESON. IMAGING 2017;45:1821–1826.

DOI： 10.1002/jmri.25489

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: A new approach for intracranial MR angiography (MRA) is introduced, using acceleration-selective arterial spin labeling (AccASL). The aim of this study was to investigate the arterial visualization and venous suppression using AccASL. Methods: Intracranial MRA images obtained by AccASL and time-of-flight (TOF) were compared in seven healthy volunteers and one patient with occlusion of the terminal portion of the left internal carotid artery. The volunteer images were assessed by measuring the contrast-to-noise ratio (CNR) between the middle cerebral artery (MCA) and white matter (WM) and between the confluence of sinuses and WM. Additionally, visualized peripheral arteries were counted and qualitative scoring of the MCA visualization and vein signal contamination was conducted. Results: The CNR at the M4 branch and the number of visualized arteries was significantly higher using AccASL compared with that in TOF (P < 0.05). In the qualitative comparison, the score for artery visualization was higher using AccASL (P < 0.05), while minimizing signal contamination by cortical veins. Additionally, in patient examination, the collateral flow visualization was better with AccASL. Conclusion: AccASL enables better efficiency for visualizing peripheral arteries compared with TOF, while suppressing cortical vein signal. Magn Reson Med 77:1996–2004, 2017.

DOI： 10.1002/mrm.26275

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: A new approach for intracranial MR angiography (MRA) is introduced, using acceleration-selective arterial spin labeling (AccASL). The aim of this study was to investigate the arterial visualization and venous suppression using AccASL. METHODS: Intracranial MRA images obtained by AccASL and time-of-flight (TOF) were compared in seven healthy volunteers and one patient with occlusion of the terminal portion of the left internal carotid artery. The volunteer images were assessed by measuring the contrast-to-noise ratio (CNR) between the middle cerebral artery (MCA) and white matter (WM) and between the confluence of sinuses and WM. Additionally, visualized peripheral arteries were counted and qualitative scoring of the MCA visualization and vein signal contamination was conducted. RESULTS: The CNR at the M4 branch and the number of visualized arteries was significantly higher using AccASL compared with that in TOF (P < 0.05). In the qualitative comparison, the score for artery visualization was higher using AccASL (P < 0.05), while minimizing signal contamination by cortical veins. Additionally, in patient examination, the collateral flow visualization was better with AccASL. CONCLUSION: AccASL enables better efficiency for visualizing peripheral arteries compared with TOF, while suppressing cortical vein signal. Magn Reson Med 77:1996-2004, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

DOI： 10.1002/mrm.26275

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Cortical lesions (CLs) frequently observed in Caucasian patients with multiple sclerosis (MS) contribute to disability. However, it remains unclear whether CLs are associated with clinical features and genetic risk factors, such as HLA-DRB1*15:01 and -DRB1*04:05 in Asian MS patients.
OBJECTIVE: To elucidate the frequency of CLs and their association with HLA-DRB1 and DPB1 alleles in Japanese MS patients.
METHODS: Three-dimensional double inversion recovery imaging and clinical information were retrospectively obtained from 92 Japanese MS patients.
RESULTS: CLs of any type, intracortical lesions (ICLs), and leukocortical lesions (LCLs) were detected in 39.1%, 26.1%, and 28.3% of patients, respectively. MS patients with ICLs had a significantly higher frequency of secondary progression and greater Expanded Disability Status Scale (EDSS) scores than those without ICLs. Similar trends were observed with CLs and LCLs. The number of all three lesion types positively correlated with EDSS scores. The frequency and number of ICLs were significantly higher in HLA-DRB1*15:01 carriers than in HLA-DRB1*15:01 non-carriers, but significantly lower in HLA-DRB1*04:05 carriers than in HLA-DRB1*04:05 non-carriers. Multivariate logistic regression analysis revealed a negative association of HLA-DRB1*04:05 with ICLs.
CONCLUSION: ICLs are associated with greater disease severity in Japanese MS patients and are partly suppressed by the HLA-DRB1*04:05 allele.

DOI： 10.1177/1352458517707067

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jocrd.2017.02.005

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To evaluate the dependence of saturation pulse power and duration on glycosaminoglycan chemical exchange saturation transfer (gagCEST) imaging and assess the degeneration of human lumbar intervertebral discs (IVDs) using this method. Materials and Methods: All images were acquired on a 3T magnetic resonance imaging (MRI) scanner. The CEST effects were measured in the glycosaminoglycan (GAG) phantoms with different concentrations. In the human study, CEST effects were measured in the nucleus pulposus of IVD. We compared the CEST effects among the different saturation pulse powers (0.4, 0.8, and 1.6 μT) or durations (0.5, 1.0, and 2.0 sec) at each Pfirrmann grade (I–V). The relationship between the CEST effects and low back pain was also evaluated. Results: The phantom study showed high correlations between the CEST effects and GAG concentration (R² = 0.863, P < 0.0001, linear regression). In the human study, the CEST effect obtained with the 0.8 μT power was significantly greater than those obtained with 0.4 (P < 0.01) and 1.6 μT power (P < 0.05) at Pfirrmann grade I. The CEST effect obtained with a 1.0-sec duration was significantly greater than those derived with 0.5 and 2.0 sec (P < 0.01) durations at Pfirrmann grades I and II. The CEST effects in the group with moderate low back pain were significantly lower than those in the groups without pain (P < 0.001) and with mild pain (P = 0.0216). Conclusion: The contrast of gagCEST imaging in the lumbar IVDs varied with saturation pulse power and duration. GagCEST imaging may serve as a tool for evaluating IVD degeneration in the lumbar spine. Level of Evidence: 2. J. Magn. Reson. Imaging 2017;45:863–871.

DOI： 10.1002/jmri.25397

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To evaluate the dependence of saturation pulse power and duration on glycosaminoglycan chemical exchange saturation transfer (gagCEST) imaging and assess the degeneration of human lumbar intervertebral discs (IVDs) using this method. MATERIALS AND METHODS: All images were acquired on a 3T magnetic resonance imaging (MRI) scanner. The CEST effects were measured in the glycosaminoglycan (GAG) phantoms with different concentrations. In the human study, CEST effects were measured in the nucleus pulposus of IVD. We compared the CEST effects among the different saturation pulse powers (0.4, 0.8, and 1.6 μT) or durations (0.5, 1.0, and 2.0 sec) at each Pfirrmann grade (I-V). The relationship between the CEST effects and low back pain was also evaluated. RESULTS: The phantom study showed high correlations between the CEST effects and GAG concentration (R2  = 0.863, P < 0.0001, linear regression). In the human study, the CEST effect obtained with the 0.8 μT power was significantly greater than those obtained with 0.4 (P < 0.01) and 1.6 μT power (P < 0.05) at Pfirrmann grade I. The CEST effect obtained with a 1.0-sec duration was significantly greater than those derived with 0.5 and 2.0 sec (P < 0.01) durations at Pfirrmann grades I and II. The CEST effects in the group with moderate low back pain were significantly lower than those in the groups without pain (P < 0.001) and with mild pain (P = 0.0216). CONCLUSION: The contrast of gagCEST imaging in the lumbar IVDs varied with saturation pulse power and duration. GagCEST imaging may serve as a tool for evaluating IVD degeneration in the lumbar spine. LEVEL OF EVIDENCE: 2 J. Magn. Reson. Imaging 2017;45:863-871.

DOI： 10.1002/jmri.25397

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objective: To evaluate the usefulness of 3D nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation enhancement imaging (SHINKEI) in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Methods: This institutional review board-approved retrospective study included 14 CIDP patients and nine normal subjects. The signal-to-noise ratio (SNR), contrast ratio (CR), and the size of the cervical ganglions and roots were measured by two raters. Results: The SNRs of the ganglions and roots were larger in patients with CIDP (9.55 ± 3.87 and 9.81 ± 3.64) than in normal subjects (7.21 ± 2.42 and 5.70 ± 2.14, P < 0.0001, respectively). The CRs of the ganglions and roots were larger in patients with CIDP (0.77 ± 0.08 and 0.68 ± 0.12) than in normal subjects (0.72 ± 0.07 and 0.53 ± 0.11, P < 0.0001, respectively). The sizes of the ganglions and the roots were larger in patients with CIDP (6.44 ± 1.61 mm and 4.89 ± 1.94 mm) than in normal subjects (5.24 ± 1.02 mm and 3.39 ± 0.80 mm, P < 0.0001, respectively). Conclusions: Patients with CIDP could be distinguished from controls on 3D SHINKEI. Key points: • 3D SHINKEI could visualize brachial plexus with high spatial resolution. • CIDP patients showed increased SNR, CR, and the size of brachial plexus. • 3D SHINKEI could discriminate CIDP patients from normal subjects.

DOI： 10.1007/s00330-016-4406-3

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVES: To investigate whether amide proton transfer (APT) MR imaging can differentiate high-grade gliomas (HGGs) from low-grade gliomas (LGGs) among gliomas without intense contrast enhancement (CE). METHODS: This retrospective study evaluated 34 patients (22 males, 12 females; age 36.0 ± 11.3 years) including 20 with LGGs and 14 with HGGs, all scanned on a 3T MR scanner. Only tumours without intense CE were included. Two neuroradiologists independently performed histogram analyses to measure the 90th-percentile (APT90) and mean (APTmean) of the tumours' APT signals. The apparent diffusion coefficient (ADC) and relative cerebral blood volume (rCBV) were also measured. The parameters were compared between the groups with Student's t-test. Diagnostic performance was evaluated with receiver operating characteristic (ROC) analysis. RESULTS: The APT90 (2.80 ± 0.59 &#37; in LGGs, 3.72 ± 0.89 in HGGs, P = 0.001) and APTmean (1.87 ± 0.49 &#37; in LGGs, 2.70 ± 0.58 in HGGs, P = 0.0001) were significantly larger in the HGGs compared to the LGGs. The ADC and rCBV values were not significantly different between the groups. Both the APT90 and APTmean showed medium diagnostic performance in this discrimination. CONCLUSIONS: APT imaging is useful in discriminating HGGs from LGGs among diffuse gliomas without intense CE. KEY POINTS: • Amide proton transfer (APT) imaging helps in grading non-enhancing gliomas • High-grade gliomas showed higher APT signal than low-grade gliomas • APT imaging showed better diagnostic performance than diffusion- and perfusion-weighted imaging.

DOI： 10.1007/s00330-016-4328-0

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: To evaluate the usefulness of 3D nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation enhancement imaging (SHINKEI) in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). METHODS: This institutional review board-approved retrospective study included 14 CIDP patients and nine normal subjects. The signal-to-noise ratio (SNR), contrast ratio (CR), and the size of the cervical ganglions and roots were measured by two raters. RESULTS: The SNRs of the ganglions and roots were larger in patients with CIDP (9.55 ± 3.87 and 9.81 ± 3.64) than in normal subjects (7.21 ± 2.42 and 5.70 ± 2.14, P < 0.0001, respectively). The CRs of the ganglions and roots were larger in patients with CIDP (0.77 ± 0.08 and 0.68 ± 0.12) than in normal subjects (0.72 ± 0.07 and 0.53 ± 0.11, P < 0.0001, respectively). The sizes of the ganglions and the roots were larger in patients with CIDP (6.44 ± 1.61 mm and 4.89 ± 1.94 mm) than in normal subjects (5.24 ± 1.02 mm and 3.39 ± 0.80 mm, P < 0.0001, respectively). CONCLUSIONS: Patients with CIDP could be distinguished from controls on 3D SHINKEI. KEY POINTS: • 3D SHINKEI could visualize brachial plexus with high spatial resolution. • CIDP patients showed increased SNR, CR, and the size of brachial plexus. • 3D SHINKEI could discriminate CIDP patients from normal subjects.

DOI： 10.1007/s00330-016-4406-3

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objectives: To investigate whether amide proton transfer (APT) MR imaging can differentiate high-grade gliomas (HGGs) from low-grade gliomas (LGGs) among gliomas without intense contrast enhancement (CE). Methods: This retrospective study evaluated 34 patients (22 males, 12 females; age 36.0 ± 11.3 years) including 20 with LGGs and 14 with HGGs, all scanned on a 3T MR scanner. Only tumours without intense CE were included. Two neuroradiologists independently performed histogram analyses to measure the 90th-percentile (APT₉₀) and mean (APT_mean) of the tumours’ APT signals. The apparent diffusion coefficient (ADC) and relative cerebral blood volume (rCBV) were also measured. The parameters were compared between the groups with Student’s t-test. Diagnostic performance was evaluated with receiver operating characteristic (ROC) analysis. Results: The APT₉₀ (2.80 ± 0.59 % in LGGs, 3.72 ± 0.89 in HGGs, P = 0.001) and APT_mean (1.87 ± 0.49 % in LGGs, 2.70 ± 0.58 in HGGs, P = 0.0001) were significantly larger in the HGGs compared to the LGGs. The ADC and rCBV values were not significantly different between the groups. Both the APT₉₀ and APT_mean showed medium diagnostic performance in this discrimination. Conclusions: APT imaging is useful in discriminating HGGs from LGGs among diffuse gliomas without intense CE. Key Points: • Amide proton transfer (APT) imaging helps in grading non-enhancing gliomas • High-grade gliomas showed higher APT signal than low-grade gliomas • APT imaging showed better diagnostic performance than diffusion- and perfusion-weighted imaging

DOI： 10.1007/s00330-016-4328-0

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To evaluate the diagnostic performance of intravoxel incoherent motion (IVIM) MR imaging and ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) in differentiating primary central nervous system lymphoma (PCNSL) from glioblastoma multiforme (GBM). Materials and Methods: Fifty patients, 17 with PCNSL and 33 with GBM, were retrospectively studied. From the 3 Tesla IVIM data, the perfusion fraction (f) and diffusion coefficient (D) were obtained. In addition, the maximum standard uptake value (SUV_max) was obtained from the FDG-PET data. Each of the three parameters was compared between PCNSL and GBM using Mann-Whitney U-test. The performance in discriminating between PCNSL and GBM was evaluated using receiver-operating characteristics analysis and area-under-the-curve (AUC) values for the three parameters. Results: The f_max and D_min values were significantly higher in GBM than in PCNSL (P < 0.01 and P < 0.0001, respectively). In addition, the SUV_max value was significantly lower in GBM than in PCNSL (P < 0.0005). The AUC values for f_max, D_min, and SUV_max were 0.756, 0.905, and 0.857, respectively. The combination of the f_max and D_min increased the diagnostic performance (AUC = 0.936) of f_max (P < 0.05), but this value was not significantly different from the values for D_min (P = 0.30). Conclusion: IVIM-MR imaging noninvasively provides useful quantitative information in distinguishing between PCNSL and GBM. J. Magn. Reson. Imaging 2016;44:1256–1261.

DOI： 10.1002/jmri.25261

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To evaluate the diagnostic performance of intravoxel incoherent motion (IVIM) MR imaging and 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) in differentiating primary central nervous system lymphoma (PCNSL) from glioblastoma multiforme (GBM). MATERIALS AND METHODS: Fifty patients, 17 with PCNSL and 33 with GBM, were retrospectively studied. From the 3 Tesla IVIM data, the perfusion fraction (f) and diffusion coefficient (D) were obtained. In addition, the maximum standard uptake value (SUVmax ) was obtained from the FDG-PET data. Each of the three parameters was compared between PCNSL and GBM using Mann-Whitney U-test. The performance in discriminating between PCNSL and GBM was evaluated using receiver-operating characteristics analysis and area-under-the-curve (AUC) values for the three parameters. RESULTS: The fmax and Dmin values were significantly higher in GBM than in PCNSL (P < 0.01 and P < 0.0001, respectively). In addition, the SUVmax value was significantly lower in GBM than in PCNSL (P < 0.0005). The AUC values for fmax , Dmin , and SUVmax were 0.756, 0.905, and 0.857, respectively. The combination of the fmax and Dmin increased the diagnostic performance (AUC = 0.936) of fmax (P < 0.05), but this value was not significantly different from the values for Dmin (P = 0.30). CONCLUSION: IVIM-MR imaging noninvasively provides useful quantitative information in distinguishing between PCNSL and GBM. J. Magn. Reson. Imaging 2016;44:1256-1261.

DOI： 10.1002/jmri.25261

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: Compared with echoplanar (EP) diffusion-weighted imaging (DWI), three-dimensional (3D) turbo field echo with diffusion-sensitized driven-equilibrium (DSDE-TFE) preparation DWI obtains images with higher spatial resolution and less susceptibility artefacts. The purpose of this study was to evaluate the feasibility of DSDE-TFE to visualize retinoblastomas compared with EP imaging. METHODS: This retrospective study was approved by our institutional review boards. Eight patients with retinoblastomas (five males and three females; age range 0-87 months; median 21 months) were studied. For the DSDE-TFE, motion-probing gradients (MPGs) were conducted at one direction with b-values of 0 and 500 s mm-2 and a voxel size of 1.5 × 1.5 × 1.5 mm3. For the EP imaging, MPGs were conducted at three directions with b-values of 0 and 1000 s mm-2 and a voxel size of 1.4 × 1.8 × 3 mm3. The apparent diffusion coefficients (ADCs) of each lesion were measured. Statistical analyses were performed with Pearson R and linear correlation coefficients. RESULTS: Intraocular lesions were clearly visualized on the DSDE-TFE without obvious geometrical distortion, whereas all showed deformity on EP images. On the DSDE-TFE, the ADCs of the lesions ranged from 0.83 × 10-3 to 2.93 × 10-3 mm2 s-1 (mean ± standard deviation 1.73 ± 0.73 × 10-3 mm2 s-1). On the EP images, the ADCs ranged from 0.53 × 10-3 to 2.03 × 10-3 mm2 s-1 (0.93 ± 0.53 × 10-3 mm2 s-1). There was a significant correlation in ADC measurement between the DSDE-TFE and EP imaging (r = 0.81, p < 0.05). CONCLUSION: With its insensitivity to field inhomogeneity and high spatial resolution, the 3D DSDE-TFE technique enabled us to assess diffusivity in retinoblastomas. Advances in knowledge: DSDE-TFE could enable us to assess the ADC of retinoblastomas without obvious geometrical distortion.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To investigate the characteristics of arterial spin-labeling magnetic resonance imaging (ASL-MRI) in central nervous system (CNS) infection. METHODS: Thirty-two patients with CNS infections underwent a pulsed ASL-MRI. The findings on ASL-MRI were retrospectively assessed for the pathogens as well as each of the following four pathology classified based on conventional MRI findings: non-purulent parenchymal involvement, meningeal involvement, abscess formation, and ventricular involvement. RESULTS: Among the 17 patients with non-purulent parenchymal involvement, ASL-MRI revealed high perfusion in 8 patients (47&#37;) and low perfusion 1 patient (6&#37;). Especially, four of five patients (80&#37;) with definite or suspected herpes simplex virus (HSV) infection showed high perfusion on ASL-MRI. Seventeen of 22 patients (77&#37;) with meningeal involvement showed high perfusion along the cerebral sulci irrespective of the pathogens. Meanwhile, 4 of 16 lesions (25&#37;) with abscess formation showed low perfusion and one of six patients (17&#37;) with ventricular involvement had high perfusion. CONCLUSIONS: The characteristics of ASL-MRI in CNS infections were clearly delineated. ASL-MRI could be helpful for monitoring the brain function in CNS infections noninvasively.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objective: To evaluate the utility of amide proton transfer (APT) imaging in estimating the Gleason score (GS) of prostate cancer (Pca). Materials and methods: Sixty-six biopsy-proven cancers were categorized into four groups according to the GS: GS-6 (3 + 3); GS-7 (3 + 4/4 + 3); GS-8 (4 + 4) and GS-9 (4 + 5/5 + 4). APT signal intensities (APT SIs) and apparent diffusion coefficient (ADC) values of each GS group were compared by one-way analysis of variance with Tukey’s HSD post hoc test. Results: The mean and standard deviation of the APT SIs (%) and ADC values (×10⁻³ mm²/s) were as follows: GS-6, 2.48 ± 0.59 and 1.16 ± 0.26; GS-7, 5.17 ± 0.66 and 0.92 ± 0.18; GS-8, 2.56 ± 0.85 and 0.86 ± 0.17; GS-9, 1.96 ± 0.75 and 0.85 ± 0.18, respectively. The APT SI of the GS-7 group was highest, and there were significant differences between the GS-6 and GS-7 groups and the GS-7 and GS-9 groups (p < 0.05). The ADC value of the GS-6 group was significantly higher than each value of the GS-7, GS-8, and GS-9 groups (p < 0.05), but no significant differences were obtained among the GS-7, GS-8, and GS-9 groups. Conclusion: The mean APT SI in Pca with a GS of 7 was higher than that for the other GS groups.

DOI： 10.1007/s10334-016-0537-4

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: To evaluate the utility of amide proton transfer (APT) imaging in estimating the Gleason score (GS) of prostate cancer (Pca). MATERIALS AND METHODS: Sixty-six biopsy-proven cancers were categorized into four groups according to the GS: GS-6 (3 + 3); GS-7 (3 + 4/4 + 3); GS-8 (4 + 4) and GS-9 (4 + 5/5 + 4). APT signal intensities (APT SIs) and apparent diffusion coefficient (ADC) values of each GS group were compared by one-way analysis of variance with Tukey's HSD post hoc test. RESULTS: The mean and standard deviation of the APT SIs (&#37;) and ADC values (×10(-3) mm(2)/s) were as follows: GS-6, 2.48 ± 0.59 and 1.16 ± 0.26; GS-7, 5.17 ± 0.66 and 0.92 ± 0.18; GS-8, 2.56 ± 0.85 and 0.86 ± 0.17; GS-9, 1.96 ± 0.75 and 0.85 ± 0.18, respectively. The APT SI of the GS-7 group was highest, and there were significant differences between the GS-6 and GS-7 groups and the GS-7 and GS-9 groups (p < 0.05). The ADC value of the GS-6 group was significantly higher than each value of the GS-7, GS-8, and GS-9 groups (p < 0.05), but no significant differences were obtained among the GS-7, GS-8, and GS-9 groups. CONCLUSION: The mean APT SI in Pca with a GS of 7 was higher than that for the other GS groups.

DOI： 10.1007/s10334-016-0537-4

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objective: Correction of contrast leakage is recommended when enhancing lesions during perfusion analysis. The purpose of this study was to assess the diagnostic performance of computed tomography perfusion (CTP) with a delay-invariant singular-value decomposition algorithm (SVD+) and a Patlak plot in differentiating glioblastomas from lymphomas. Materials and methods: This prospective study included 17 adult patients (12 men and 5 women) with pathologically proven glioblastomas (n = 10) and lymphomas (n = 7). CTP data were analyzed using SVD+ and a Patlak plot. The relative tumor blood volume and flow compared to contralateral normal-appearing gray matter (rCBV and rCBF derived from SVD+, and rBV and rFlow derived from the Patlak plot) were used to differentiate between glioblastomas and lymphomas. The Mann-Whitney U test and receiver operating characteristic (ROC) analyses were used for statistical analysis. Results: Glioblastomas showed significantly higher rFlow (3.05 ± 0.49, mean ± standard deviation) than lymphomas (1.56 ± 0.53; P < 0.05). There were no statistically significant differences between glioblastomas and lymphomas in rBV (2.52 ± 1.57 vs. 1.03 ± 0.51; P > 0.05), rCBF (1.38 ± 0.41 vs. 1.29 ± 0.47; P > 0.05), or rCBV (1.78 ± 0.47 vs. 1.87 ± 0.66; P > 0.05). ROC analysis showed the best diagnostic performance with rFlow (Az = 0.871), followed by rBV (Az = 0.771), rCBF (Az = 0.614), and rCBV (Az = 0.529). Conclusion: CTP analysis with a Patlak plot was helpful in differentiating between glioblastomas and lymphomas, but CTP analysis with SVD+ was not.

DOI： 10.1016/j.neurad.2016.01.147

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: Correction of contrast leakage is recommended when enhancing lesions during perfusion analysis. The purpose of this study was to assess the diagnostic performance of computed tomography perfusion (CTP) with a delay-invariant singular-value decomposition algorithm (SVD+) and a Patlak plot in differentiating glioblastomas from lymphomas. MATERIALS AND METHODS: This prospective study included 17 adult patients (12 men and 5 women) with pathologically proven glioblastomas (n=10) and lymphomas (n=7). CTP data were analyzed using SVD+ and a Patlak plot. The relative tumor blood volume and flow compared to contralateral normal-appearing gray matter (rCBV and rCBF derived from SVD+, and rBV and rFlow derived from the Patlak plot) were used to differentiate between glioblastomas and lymphomas. The Mann-Whitney U test and receiver operating characteristic (ROC) analyses were used for statistical analysis. RESULTS: Glioblastomas showed significantly higher rFlow (3.05±0.49, mean±standard deviation) than lymphomas (1.56±0.53; P<0.05). There were no statistically significant differences between glioblastomas and lymphomas in rBV (2.52±1.57 vs. 1.03±0.51; P>0.05), rCBF (1.38±0.41 vs. 1.29±0.47; P>0.05), or rCBV (1.78±0.47 vs. 1.87±0.66; P>0.05). ROC analysis showed the best diagnostic performance with rFlow (Az=0.871), followed by rBV (Az=0.771), rCBF (Az=0.614), and rCBV (Az=0.529). CONCLUSION: CTP analysis with a Patlak plot was helpful in differentiating between glioblastomas and lymphomas, but CTP analysis with SVD+ was not.

DOI： 10.1016/j.neurad.2016.01.147

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: Diffusivity of pituitary adenoma has not been investigated fully. The purpose of this study was to evaluate the feasibility of turbo field echo with diffusion-sensitized driven-equilibrium (DSDE-TFE) preparation for pituitary adenoma in the sella turcica and unaffected anterior lobe of the pituitary gland. METHODS: This retrospective study included 23 adult patients with pituitary adenomas. Among them, 6 each were prolactin-producing adenomas and growth hormone-producing adenomas (GH) and the remaining 11 were non-functioning adenomas (NON). The apparent diffusion coefficients (ADCs) were measured in the pituitary adenoma and in the unaffected pituitary gland using coronal reformatted plane. RESULTS: All pituitary adenomas were clearly visualized on DSDE-TFE and ADC maps without obvious geometrical distortion. There were no statistically significant differences in ADC of the all pituitary adenoma (1.50 ± 0.61 × 10(-3) mm(2) s(-1)) and the unaffected anterior lobe of the pituitary gland (1.49 ± 0.37 × 10(-3) mm(2) s(-1), p = 0.99). The ADC in prolactin-producing adenomas (2.04 ± 0.76 × 10(-3) mm(2) s(-1)) was significantly higher than that in GH (1.26 ± 0.47 × 10(-3) mm(2) s(-1); p < 0.05) and NON (1.33 ± 0.42 × 10(-3) mm(2) s(-1); p = 0.04). There was no statistically significant difference between GH and NON (p = 0.97). The intraclass correlation coefficient for ADC was 0.985 in adenomas and 0.635 in unaffected glands. CONCLUSION: With its insensitivity to field inhomogeneity and high spatial resolution, DSDE-TFE proved a feasible method for evaluating the diffusivity in the pituitary gland and adenoma. ADVANCES IN KNOWLEDGE: DSDE-TFE could enable us to assess ADC of pituitary adenoma in the sella turcica with high resolution and few susceptibility artefacts.

DOI： 10.1259/bjr.20150755

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objective The aim of the study was to evaluate the prognostic utility of computed tomography (CT) histogram analysis with an automated whole-brain extraction algorithm in patients with post-cardiac arrest syndrome (PCAS). Methods Computed tomography data from consecutive patients between January 2009 and February 2012 were obtained and retrospectively analyzed. All CT images were obtained using a 64-detector-row CT scanner with a slice thickness of 4.0 mm. A brain region was extracted from the whole-brain CT images using our original automated algorithm and used for the subsequent histogram analysis. The obtained histogram statistics (mean brain tissue CT value, kurtosis, and skewness), as well as clinical parameters, were compared between the good and poor outcome groups using the Student t test. In addition, receiver operating characteristic curve analysis was performed for the discrimination between the 2 groups for each parameter. Results One hundred thirty-eight consecutive PCAS patients were enrolled. The patients were classified into good (n = 47) and poor (n = 91) outcome groups. The mean brain tissue CT value was significantly higher in the good outcome group than in the poor outcome group (P < 0.05). Kurtosis, skewness, and age were significantly lower in the good outcome group than in the poor outcome group (P < 0.0001, P < 0.05, and P < 0.05, respectively). The area-under-the-curve values for kurtosis, mean brain tissue CT value, skewness, and age were 0.751, 0.639, 0.623, and 0.626, respectively. A combination of the 4 parameters increased the diagnostic performance (area under the curve = 0.814). Conclusions Histogram analysis of whole-brain CT images with our automated extraction algorithm is useful for assessing the outcome of PCAS patients.

DOI： 10.1097/RCT.0000000000000396

記述言語：英語   掲載種別：研究論文（学術雑誌）  

We report a case of leiomyosarcoma of the thoracic spine. Primary leiomyosarcoma is a malignant connective tissue tumor originating from smooth muscle cells. Leiomyosarcoma frequently occurs in the uterus, retroperitoneal space, gastrointestinal tract, and deep soft tissues; primary leiomyosarcoma of the bone is rare. The MR imaging including intravoxel incoherent motion (IVIM) imaging findings of the current case indicated a low diffusion coefficient and high blood flow, which were in concurrence with high cell density on histology and increased vascularity by angiography. Although some benign tumors such as osteoblastoma and giant cell tumor would show similar findings on IVIM imaging, these additional imaging features may narrow the differential diagnosis of spinal tumors.

DOI： 10.1007/s00062-015-0420-0

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To document long-term morphological changes of Chiari type II malformation (CM-II) following closure of spina bifida manifesta (SBM). METHODS: We retrospectively evaluated postnatal magnetic resonance images of the CM-II and posterior fossa (PF) in 28 consecutive cases. We measured changes in vertebral level and length of the cerebellar peg (CP), cerebrospinal fluid (CSF) spaces anterior and posterior to the cerebrospinal junction, PF area, and the anteroposterior diameters of the foramen magnum (FM) and C1 vertebra. We examined the morphological differences between the cases with and without ventriculoperitoneal (VP) shunting and derived predicted means by nonlinear mixed-effect modeling. RESULTS: At birth, there were significant differences in CP length, PF area, and FM and C1 diameters between those who underwent VP shunting and those who did not. In cases with a CP below C1, VP shunting was required in every case but one. In those with visible CSF space at birth, VP shunts were not required. In 17 of 18 cases with a CP below C1, the vertebral level ascended by mean two vertebral levels (range 0-5 levels) within 4-6 months of delivery. In the remaining case, slowly progressive hydrocephalus and delayed CP descent required VP shunting at 8 months. Predicted mean CP length and FM and C1 diameters were greater in those who underwent VP shunting, but there was no difference in predicted mean PF area. CONCLUSION: The morphology of CM-II and the presence of hydrocephalus influence each other in children who have undergone postnatal SBM repair.

DOI： 10.1007/s00381-016-3041-2

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To document long-term morphological changes of Chiari type II malformation (CM-II) following closure of spina bifida manifesta (SBM). Methods: We retrospectively evaluated postnatal magnetic resonance images of the CM-II and posterior fossa (PF) in 28 consecutive cases. We measured changes in vertebral level and length of the cerebellar peg (CP), cerebrospinal fluid (CSF) spaces anterior and posterior to the cerebrospinal junction, PF area, and the anteroposterior diameters of the foramen magnum (FM) and C1 vertebra. We examined the morphological differences between the cases with and without ventriculoperitoneal (VP) shunting and derived predicted means by nonlinear mixed-effect modeling. Results: At birth, there were significant differences in CP length, PF area, and FM and C1 diameters between those who underwent VP shunting and those who did not. In cases with a CP below C1, VP shunting was required in every case but one. In those with visible CSF space at birth, VP shunts were not required. In 17 of 18 cases with a CP below C1, the vertebral level ascended by mean two vertebral levels (range 0–5 levels) within 4–6 months of delivery. In the remaining case, slowly progressive hydrocephalus and delayed CP descent required VP shunting at 8 months. Predicted mean CP length and FM and C1 diameters were greater in those who underwent VP shunting, but there was no difference in predicted mean PF area. Conclusion: The morphology of CM-II and the presence of hydrocephalus influence each other in children who have undergone postnatal SBM repair.

DOI： 10.1007/s00381-016-3041-2

記述言語：英語   掲載種別：研究論文（学術雑誌）  

In this study, we evaluated the dependence of saturation pulse length on APT imaging of diffuse gliomas using a parallel transmission-based technique. Twenty-two patients with diffuse gliomas (9 low-grade gliomas, LGGs, and 13 high-grade gliomas, HGGs) were included in the study. APT imaging was conducted at 3T with a 2-channel parallel transmission scheme using three different saturation pulse lengths (0.5 s, 1.0 s, 2.0 s). The 2D fast spin-echo sequence was used for imaging. Z-spectrum was obtained at 25 frequency off-sets from -6 to +6 ppm (step 0.5 ppm). A point-by-point B0 correction was performed with a B0 map. Magnetization transfer ratio (MTR_asym) and ΔMTR_asym (contrast between tumor and normal white matter) at 3.5 ppm were compared among different saturation lengths. A significant increase in MTR_asym (3.5 ppm) of HGG was found when the length of saturation pulse became longer (3.09 ± 0.54% at 0.5 s, 3.83 ± 0.67% at 1 s, 4.12 ± 0.97% at 2 s), but MTR_asym (3.5 ppm) was not different among the saturation lengths in LGG. ΔMTR_asym (3.5 ppm) increased with the length of saturation pulse in both LGG (0.48 ± 0.56% at 0.5 s, 1.28 ± 0.56% at 1 s, 1.88 ± 0.56% at 2 s and HGG (1.72 ± 0.54% at 0.5 s, 2.90 ± 0.49% at 1 s, 3.83 ± 0.88% at 2 s). In both LGG and HGG, APT-weighted contrast was enhanced with the use of longer saturation pulses.

DOI： 10.1371/journal.pone.0155925

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Our goals were to develop and establish nanoparticle (NP)-facilitated inhalational gene delivery, and to validate its biomedical application by testing the hypothesis that targeted upregulation of pulmonary erythropoietin receptor (EpoR) expression protects against lung injury. Poly-lactic-co-glycolic acid (PLGA) NPs encapsulating various tracers were characterized and nebulizated into rat lungs. Widespread NP uptake and distribution within alveolar cells were visualized by magnetic resonance imaging, and fluorescent and electron microscopy. Inhalation of nebulized NPs bearing EpoR cDNA upregulated pulmonary EpoR expression and downstream signal transduction (ERK1/2 and STAT5 phosphorylation) in rats for up to 21 days, and attenuated hyperoxia-induced damage in lung tissue based on apoptosis, oxidative damage of DNA, protein and lipid, tissue edema, and alveolar morphology compared to vector-treated control animals. These results establish the feasibility and therapeutic efficacy of NP-facilitated cDNA delivery to the lung, and demonstrate that targeted pulmonary EpoR upregulation mitigates acute oxidative lung damage.

DOI： 10.1016/j.nano.2015.10.004

記述言語：英語   掲載種別：研究論文（学術雑誌）  

UNLABELLED: Our goals were to develop and establish nanoparticle (NP)-facilitated inhalational gene delivery, and to validate its biomedical application by testing the hypothesis that targeted upregulation of pulmonary erythropoietin receptor (EpoR) expression protects against lung injury. Poly-lactic-co-glycolic acid (PLGA) NPs encapsulating various tracers were characterized and nebulizated into rat lungs. Widespread NP uptake and distribution within alveolar cells were visualized by magnetic resonance imaging, and fluorescent and electron microscopy. Inhalation of nebulized NPs bearing EpoR cDNA upregulated pulmonary EpoR expression and downstream signal transduction (ERK1/2 and STAT5 phosphorylation) in rats for up to 21 days, and attenuated hyperoxia-induced damage in lung tissue based on apoptosis, oxidative damage of DNA, protein and lipid, tissue edema, and alveolar morphology compared to vector-treated control animals. These results establish the feasibility and therapeutic efficacy of NP-facilitated cDNA delivery to the lung, and demonstrate that targeted pulmonary EpoR upregulation mitigates acute oxidative lung damage. FROM THE CLINICAL EDITOR: Acute lung injury often results in significant morbidity and mortality, and current therapeutic modalities have proven to be ineffective. In this article, the authors developed nanocarrier based gene therapy in an attempt to upregulate the expression of pulmonary erythropoietin receptor in an animal model. Inhalation delivery resulted in reduction of lung damage.

DOI： 10.1016/j.nano.2015.10.004

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objective: Compared with echoplanar (EP) diffusionweighted imaging (DWI), three-dimensional (3D) turbo field echo with diffusion-sensitized driven-equilibrium (DSDE-TFE) preparation DWI obtains images with higher spatial resolution and less susceptibility artefacts. The purpose of this study was to evaluate the feasibility of DSDE-TFE to visualize retinoblastomas compared with EP imaging. Methods: This retrospective study was approved by our institutional review boards. Eight patients with retinoblastomas (five males and three females; age range 0-87 months; median 21 months) were studied. For the DSDE-TFE, motion-probing gradients (MPGs) were conducted at one direction with b-values of 0 and 500smm22 and a voxel size of 1.531.531.5mm3. For the EP imaging, MPGs were conducted at three directions with b-values of 0 and 1000smm22 and a voxel size of 1.431.833mm3. The apparent diffusion coefficients (ADCs) of each lesion were measured. Statistical analyses were performed with Pearson R and linear correlation coefficients. Results: Intraocular lesions were clearly visualized on the DSDE-TFE without obvious geometrical distortion, whereas all showed deformity on EP images. On the DSDE-TFE, the ADCs of the lesions ranged from 0.8331023 to 2.9331023mm2 s21 (mean 6 standard deviation 1.7360.7331023mm2 s21). On the EP images, the ADCs ranged from 0.5331023 to 2.0331023mm2 s21 (0.9360.5331023mm2 s21). There was a significant correlation in ADC measurement between the DSDE-TFE and EP imaging (r50.81, p,0.05). Conclusion: With its insensitivity to field inhomogeneity and high spatial resolution, the 3D DSDE-TFE technique enabled us to assess diffusivity in retinoblastomas.

DOI： 10.1259/bjr.20160074

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Amide proton transfer (APT) contrast imaging is based on the chemical exchange saturation transfer (CEST) of protons between the amide groups and bulk water. Here, we demonstrate the effect of the saturation pulse duration on CEST in APT imaging with use of a clinical MR scanner. Four samples were prepared from chicken egg white diluted with H2O. Experiments were performed on a 3T clinical MR scanner with use of a body coil for two-channel parallel radiofrequency transmission. APT images were acquired at six frequency offsets (± 3.0, ± 3.5, ± 4.0 ppm) with respect to the water resonance as well as one far off-resonant frequency (-160 ppm) for signal normalization. The CEST effect was defined as asymmetry of the magnetization transfer ratio at 3.5 ppm. We measured the CEST effects in the egg white samples with different concentrations at seven saturation pulse durations. The influence of the extension of repetition time (TR) on the CEST effect was also evaluated. The CEST effect was not influenced by the change in TR. The CEST effect was increased significantly with the concentration when the duration was ≥1.0 s (P < 0.01). The CEST effect was highly correlated with the concentration at all saturation pulse durations, and its increase ratio was higher at longer saturation pulse durations. In conclusion, a long saturation pulse duration is useful for the sensitive detection of mobile proteins and peptides in APT imaging.

DOI： 10.1007/s12194-015-0326-1

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Our aim was to assess the diagnostic performance of intravoxel incoherent motion (IVIM) MR imaging for differentiating high-grade gliomas (HGGs) from low-grade gliomas (LGGs). METHODS: Forty-five patients with diffuse glioma (age 50.9 ± 20.4 y; 26 males, 19 females) were assessed with IVIM imaging using 13 b-values (0-1000 s/mm(2)) at 3T. The perfusion fraction (f), true diffusion coefficient (D), and pseudo-diffusion coefficient (D*) were calculated by fitting the bi-exponential model. The apparent diffusion coefficient (ADC) was obtained with 2 b-values (0 and 1000 s/mm(2)). Relative cerebral blood volume was measured by the dynamic susceptibility contrast method. Two observers independently measured D, ADC, D*, and f, and these measurements were compared between the LGG group (n = 16) and the HGG group (n = 29). RESULTS: Both D (1.26 ± 0.37 mm(2)/s in LGG, 0.94 ± 0.19 mm(2)/s in HGG; P < .001) and ADC (1.28 ± 0.35 mm(2)/s in LGG, 1.03 ± 0.19 mm(2)/s in HGG; P < .01) were lower in the HGG group. D was lower than ADC in the LGG (P < .05) and HGG groups (P < .0001). D* was not different between the groups. The f-values were significantly larger in HGG (17.5 ± 6.3&#37;) than in LGG (5.8 ± 3.8&#37;; P < .0001) and correlated with relative cerebral blood volume (r = 0.85; P < .0001). Receiver operating characteristic analyses showed areas under curve of 0.95 with f, 0.78 with D, 0.73 with ADC, and 0.60 with D*. CONCLUSION: IVIM imaging is useful in differentiating HGGs from LGGs.

DOI： 10.1093/neuonc/nov147

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND AND PURPOSE: Glioblastoma multiforme is highly aggressive and the most common type of primary malignant brain tumor in adults. Imaging biomarkers may provide prognostic information for patients with this condition. Patients with glioma with isocitrate dehydrogenase 1 (IDH1) mutations have a better clinical outcome than those without such mutations. Our purpose was to investigate whether the IDH1 mutation status in glioblastoma multiforme can be predicted by using MR imaging. MATERIALS AND METHODS: We retrospectively studied 55 patients with glioblastoma multiforme with wild type IDH1 and 11 patients with mutant IDH1. Absolute tumor blood flow and relative tumor blood flow within the enhancing portion of each tumor were measured by using arterial spin-labeling data. In addition, the maximum necrosis area, the percentage of cross-sectional necrosis area inside the enhancing lesions, and the minimum and mean apparent diffusion coefficients were obtained from contrast-enhanced T1-weighted images and diffusion-weighted imaging data. Each of the 6 parameters was compared between patients with wild type IDH1 and mutant IDH1 by using the Mann-Whitney U test. The performance in discriminating between the 2 entities was evaluated by using receiver operating characteristic analysis. RESULTS: Absolute tumor blood flow, relative tumor blood flow, necrosis area, and percentage of cross-sectional necrosis area inside the enhancing lesion were significantly higher in patients with wild type IDH1 than in those with mutant IDH1 (P < .05 each). In contrast, no significant difference was found in the ADC_minimum and ADC_mean. The area under the curve for absolute tumor blood flow, relative tumor blood flow, percentage of cross-sectional necrosis area inside the enhancing lesion, and necrosis area were 0.850, 0.873, 0.739, and 0.772, respectively. CONCLUSIONS: Tumor blood flow and necrosis area calculated from MR imaging are useful for predicting the IDH1 mutation status.

DOI： 10.3174/ajnr.A4491

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objective: Diffusivity of pituitary adenoma has not been investigated fully. The purpose of this study was to evaluate the feasibility of turbo field echo with diffusion-sensitized driven-equilibrium (DSDE-TFE) preparation for pituitary adenoma in the sella turcica and unaffected anterior lobe of the pituitary gland. Methods: This retrospective study included 23 adult patients with pituitary adenomas. Among them, 6 each were prolactin-producing adenomas and growth hormoneproducing adenomas (GH) and the remaining 11 were non-functioning adenomas (NON). The apparent diffusion coefficients (ADCs) were measured in the pituitary adenoma and in the unaffected pituitary gland using coronal reformatted plane. Results: All pituitary adenomas were clearly visualized on DSDE-TFE and ADC maps without obvious geometrical distortion. There were no statistically significant differences in ADC of the all pituitary adenoma (1.506 0.61×10^-3mm² s^-1) and the unaffected anterior lobe of the pituitary gland (1.49±0.37×10^-3mm² s^-1, p=0.99). The ADC in prolactin-producing adenomas (2.04± 0.7×10^-3mm² s^-1) was significantly higher than that in GH (1.26±0.47×10^-3mm² s^-1; p<0.05) and NON (1.33±0.42×10^-3mm² s^-1; p=0.04). There was no statistically significant difference between GH and NON (p=0.97). The intraclass correlation coefficient for ADC was 0.985 in adenomas and 0.635 in unaffected glands. Conclusion: With its insensitivity to field inhomogeneity and high spatial resolution, DSDE-TFE proved a feasible method for evaluating the diffusivity in the pituitary gland and adenoma. Advances in knowledge: DSDE-TFE could enable us to assess ADC of pituitary adenoma in the sella turcica with high resolution and few susceptibility artefacts.

DOI： 10.1259/bjr.20150755

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Amide proton transfer (APT) contrast imaging is based on the chemical exchange saturation transfer (CEST) of protons between the amide groups and bulk water. Here, we demonstrate the effect of the saturation pulse duration on CEST in APT imaging with use of a clinical MR scanner. Four samples were prepared from chicken egg white diluted with H₂O. Experiments were performed on a 3T clinical MR scanner with use of a body coil for two-channel parallel radiofrequency transmission. APT images were acquired at six frequency offsets (± 3.0, ± 3.5, ± 4.0 ppm) with respect to the water resonance as well as one far off-resonant frequency (−160 ppm) for signal normalization. The CEST effect was defined as asymmetry of the magnetization transfer ratio at 3.5 ppm. We measured the CEST effects in the egg white samples with different concentrations at seven saturation pulse durations. The influence of the extension of repetition time (TR) on the CEST effect was also evaluated. The CEST effect was not influenced by the change in TR. The CEST effect was increased significantly with the concentration when the duration was ≥1.0 s (P < 0.01). The CEST effect was highly correlated with the concentration at all saturation pulse durations, and its increase ratio was higher at longer saturation pulse durations. In conclusion, a long saturation pulse duration is useful for the sensitive detection of mobile proteins and peptides in APT imaging.

DOI： 10.1007/s12194-015-0326-1

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Background Our aim was to assess the diagnostic performance of intravoxel incoherent motion (IVIM) MR imaging for differentiating high-grade gliomas (HGGs) from low-grade gliomas (LGGs). Methods Forty-five patients with diffuse glioma (age 50.9 ± 20.4 y; 26 males, 19 females) were assessed with IVIM imaging using 13 b-values (0-1000 s/mm²) at 3T. The perfusion fraction (f), true diffusion coefficient (D), and pseudo-diffusion coefficient (D∗) were calculated by fitting the bi-exponential model. The apparent diffusion coefficient (ADC) was obtained with 2 b-values (0 and 1000 s/mm²). Relative cerebral blood volume was measured by the dynamic susceptibility contrast method. Two observers independently measured D, ADC, D∗, and f, and these measurements were compared between the LGG group (n = 16) and the HGG group (n = 29). Results Both D (1.26 ± 0.37 mm²/s in LGG, 0.94 ± 0.19 mm²/s in HGG; P <. 001) and ADC (1.28 ± 0.35 mm²/s in LGG, 1.03 ± 0.19 mm²/s in HGG; P <. 01) were lower in the HGG group. D was lower than ADC in the LGG (P <. 05) and HGG groups (P <. 0001). D∗ was not different between the groups. The f-values were significantly larger in HGG (17.5 ± 6.3%) than in LGG (5.8 ± 3.8%; P <. 0001) and correlated with relative cerebral blood volume (r = 0.85; P <. 0001). Receiver operating characteristic analyses showed areas under curve of 0.95 with f, 0.78 with D, 0.73 with ADC, and 0.60 with D∗. Conclusion IVIM imaging is useful in differentiating HGGs from LGGs.

DOI： 10.1093/neuonc/nov147

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objective: To test the validity of diffusion tensor imaging (DTI) measures of tissue injury by examining such measures in a white matter structure with well-defined function, the medial longitudinal fasciculus (MLF). Injury to the MLF underlies internuclear ophthalmoparesis (INO). Methods: 40 MS patients with chronic INO and 15 healthy controls were examined under an IRB-approved protocol. Tissue integrity of the MLF was characterized by DTI parameters: longitudinal diffusivity (LD), transverse diffusivity (TD), mean diffusivity (MD) and fractional anisotropy (FA). Severity of INO was quantified by infrared oculography to measure versional disconjugacy index (VDI). Results: LD was significantly lower in patients than in controls in the medulla-pons region of the MLF (p < 0.03). FA was also lower in patients in the same region (p < 0.0004). LD of the medullapons region correlated with VDI (R = -0.28, p < 0.05) as did FA in the midbrain section (R = 0.31, p < 0.02). Conclusions: This study demonstrates that DTI measures of brain tissue injury can detect injury to a functionally relevant white matter pathway, and that such measures correlate with clinically accepted evaluation indices for INO. The results validate DTI as a useful imaging measure of tissue integrity.

DOI： 10.1371/journal.pone.0147863

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To investigate the characteristics of arterial spin-labeling magnetic resonance imaging (ASL-MRI) in central nervous system (CNS) infection. Methods: Thirty-two patients with CNS infections underwent a pulsed ASL-MRI. The findings on ASL-MRI were retrospectively assessed for the pathogens as well as each of the following four pathology classified based on conventional MRI findings: non-purulent parenchymal involvement, meningeal involvement, abscess formation, and ventricular involvement. Results: Among the 17 patients with non-purulent parenchymal involvement, ASL-MRI revealed high perfusion in 8 patients (47%) and low perfusion 1 patient (6%). Especially, four of five patients (80%) with definite or suspected herpes simplex virus (HSV) infection showed high perfusion on ASL-MRI. Seventeen of 22 patients (77%) with meningeal involvement showed high perfusion along the cerebral sulci irrespective of the pathogens. Meanwhile, 4 of 16 lesions (25%) with abscess formation showed low perfusion and one of six patients (17%) with ventricular involvement had high perfusion. Conclusions: The characteristics of ASL-MRI in CNS infections were clearly delineated. ASLMRI could be helpful for monitoring the brain function in CNS infections noninvasively.

DOI： 10.2463/mrms.mp.2015-0140

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The aim of the study was to assess the feasibility of high-resolution three-dimensional diffusion-weighted images (HR3D-DWIs)/multi-detector row CT (MDCT) images’ data fusion for surgical planning for cholesteatoma. A total of 12 patients (7 male and 5 female; age range 11–72 years; mean 38.1 years) with cholesteatoma underwent preoperative MRI using a 3.0-T clinical unit and an 8-channel array-head coil. For each subject, HR3D-DWIs were obtained using a turbo field-echo with diffusion-sensitized driven-equilibrium preparation with 1.5 mm iso-voxel dimension. These patients also underwent MDCT with a slice thickness of 0.5 mm. Fusion of the HR3D-DWIs and MDCT images was performed using an automated rigid registration and subsequent manual fine-tuning by a board-certified neuroradiologist on a workstation. Fused images were compared to CT and findings confirmed based on operation reports. On the fused images, the extent of the cholesteatoma, which was depicted as a conspicuous high-intensity lesion could be easily evaluated with background bony structures. In all patients, the location and extent of the cholesteatoma on the fused images corresponded well with the intraoperative findings. Image fusion between HR3D-DWIs and MDCT images is feasible, and provides valuable preoperative information for surgical planning to otorhinolaryngologists.

DOI： 10.1007/s00405-014-3467-7

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The aim of the study was to assess the feasibility of high-resolution three-dimensional diffusion-weighted images (HR3D-DWIs)/multi-detector row CT (MDCT) images' data fusion for surgical planning for cholesteatoma. A total of 12 patients (7 male and 5 female; age range 11-72 years; mean 38.1 years) with cholesteatoma underwent preoperative MRI using a 3.0-T clinical unit and an 8-channel array-head coil. For each subject, HR3D-DWIs were obtained using a turbo field-echo with diffusion-sensitized driven-equilibrium preparation with 1.5 mm iso-voxel dimension. These patients also underwent MDCT with a slice thickness of 0.5 mm. Fusion of the HR3D-DWIs and MDCT images was performed using an automated rigid registration and subsequent manual fine-tuning by a board-certified neuroradiologist on a workstation. Fused images were compared to CT and findings confirmed based on operation reports. On the fused images, the extent of the cholesteatoma, which was depicted as a conspicuous high-intensity lesion could be easily evaluated with background bony structures. In all patients, the location and extent of the cholesteatoma on the fused images corresponded well with the intraoperative findings. Image fusion between HR3D-DWIs and MDCT images is feasible, and provides valuable preoperative information for surgical planning to otorhinolaryngologists.

DOI： 10.1007/s00405-014-3467-7

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose To evaluate the reproducibility of amide proton transfer (APT) imaging of brain tumors using a parallel transmission-based technique. Materials and Methods Thirteen patients with brain tumors (four low-grade gliomas, three glioblastoma multiforme, five meningiomas, and one malignant lymphoma) were included in the study. APT imaging was conducted at 3T using a 2-channel parallel transmission scheme with a saturation time of 2 seconds and B₁ amplitude of 2 μT. A 2D fast spin-echo sequence with driven-equilibrium refocusing was used for imaging. Z-spectra were obtained at 25 frequency offsets from -6 to +6 ppm (step 0.5 ppm). A point-by-point B₀ correction was performed with a B₀ map. A scan-rescan reproducibility test was performed in two sessions on separate days for each patient. The interval between the two sessions was 4.8±3.5 days. Regions-of-interest (ROIs) were placed to include the whole tumor for each case. A mean and 90-percentile value of APT signal for the whole tumor histogram was calculated for each session. The between-session and within-session reproducibility was evaluated using linear regression analysis, intraclass correlation coefficient (ICC), and a Bland-Altman plot. Results The mean and 90-percentile values of the APT signal for whole tumor ROI showed excellent agreements between the two sessions, with R² of 0.91 and 0.96 in the linear regression analysis and ICC of 0.95 and 0.97, respectively. Conclusion Parallel transmission-based APT imaging of brain tumors showed good reproducibility.

DOI： 10.1002/jmri.24895

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To evaluate the reproducibility of amide proton transfer (APT) imaging of brain tumors using a parallel transmission-based technique. MATERIALS AND METHODS: Thirteen patients with brain tumors (four low-grade gliomas, three glioblastoma multiforme, five meningiomas, and one malignant lymphoma) were included in the study. APT imaging was conducted at 3T using a 2-channel parallel transmission scheme with a saturation time of 2 seconds and B1 amplitude of 2 μT. A 2D fast spin-echo sequence with driven-equilibrium refocusing was used for imaging. Z-spectra were obtained at 25 frequency offsets from -6 to +6 ppm (step 0.5 ppm). A point-by-point B0 correction was performed with a B0 map. A scan-rescan reproducibility test was performed in two sessions on separate days for each patient. The interval between the two sessions was 4.8 ± 3.5 days. Regions-of-interest (ROIs) were placed to include the whole tumor for each case. A mean and 90-percentile value of APT signal for the whole tumor histogram was calculated for each session. The between-session and within-session reproducibility was evaluated using linear regression analysis, intraclass correlation coefficient (ICC), and a Bland-Altman plot. RESULTS: The mean and 90-percentile values of the APT signal for whole tumor ROI showed excellent agreements between the two sessions, with R(2) of 0.91 and 0.96 in the linear regression analysis and ICC of 0.95 and 0.97, respectively. CONCLUSION: Parallel transmission-based APT imaging of brain tumors showed good reproducibility.

DOI： 10.1002/jmri.24895

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Background: Pure dysarthria (PD) and dysarthria-facial paresis syndrome (DFP) mainly result from lenticulostriate artery territory infarction. PD and DFP are rare clinical entities, often grouped without distinction. The purpose of this study was to examine clinical and radiographic differences between PD and DFP due to unilateral internal capsule and/or corona radiata infarction. Methods: Using a database that included consecutive patients with ischemic stroke admitted to the neurological stroke units of three hospitals within 7 days from onset between September 2011 and April 2014, we retrospectively extracted first-ever stroke patient data, who presented with PD or DFP with a single ischemic lesion localized in the internal capsule and/or corona radiata. Patients with weakness, ataxia, sensory deficit, or cortical symptoms were excluded. Ischemic lesion volume was calculated by the ABC/2 method on diffusion-weighted imaging (DWI). DWI images were normalized and superimposed to the template for PD and DFP. We compared patients' characteristics between PD and DFP. Results: A total of 2126 patients, including 65 patients (3.1 %) with PD or DFP, were registered. Of these, 13 PD patients and 18 patients with DFP due to unilateral internal capsule and/or corona radiata infarction were included for analysis. Compared with DFP patients, PD patients had longer onset-to-door time (median 37.5 vs. 10.8 h, p = 0.031), shorter vertical length (C component) of ischemic lesions (median 12.0 vs. 18.8 mm, p = 0.007), and smaller ischemic lesion volume (median 285 vs. 828 mm³, p = 0.023). Ischemic lesions causing PD were located more frequently in the left hemisphere than DFP (92 % vs. 56 %, p = 0.045). The superimposed lesion pattern indicated that DFP had lesions more medial and involving posterior portions of the putamen and the caudate body, as well as more of the genu and posterior limb of the internal capsule, than PD. Ninety days after onset, symptoms disappeared in 21 (72 %) out of 29 patients. Conclusions: In cerebral infarction limited to the internal capsule and/or corona radiata, PD is derived from smaller and left-sided lesions with delay in diagnosis compared with DFP. The clinical course of those with PD and DFP might be benign.

DOI： 10.1186/s12883-015-0439-5

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Pure dysarthria (PD) and dysarthria-facial paresis syndrome (DFP) mainly result from lenticulostriate artery territory infarction. PD and DFP are rare clinical entities, often grouped without distinction. The purpose of this study was to examine clinical and radiographic differences between PD and DFP due to unilateral internal capsule and/or corona radiata infarction. METHODS: Using a database that included consecutive patients with ischemic stroke admitted to the neurological stroke units of three hospitals within 7 days from onset between September 2011 and April 2014, we retrospectively extracted first-ever stroke patient data, who presented with PD or DFP with a single ischemic lesion localized in the internal capsule and/or corona radiata. Patients with weakness, ataxia, sensory deficit, or cortical symptoms were excluded. Ischemic lesion volume was calculated by the ABC/2 method on diffusion-weighted imaging (DWI). DWI images were normalized and superimposed to the template for PD and DFP. We compared patients' characteristics between PD and DFP. RESULTS: A total of 2126 patients, including 65 patients (3.1&#37;) with PD or DFP, were registered. Of these, 13 PD patients and 18 patients with DFP due to unilateral internal capsule and/or corona radiata infarction were included for analysis. Compared with DFP patients, PD patients had longer onset-to-door time (median 37.5 vs. 10.8 h, p = 0.031), shorter vertical length (C component) of ischemic lesions (median 12.0 vs. 18.8 mm, p = 0.007), and smaller ischemic lesion volume (median 285 vs. 828 mm(3), p = 0.023). Ischemic lesions causing PD were located more frequently in the left hemisphere than DFP (92&#37; vs. 56&#37;, p = 0.045). The superimposed lesion pattern indicated that DFP had lesions more medial and involving posterior portions of the putamen and the caudate body, as well as more of the genu and posterior limb of the internal capsule, than PD. Ninety days after onset, symptoms disappeared in 21 (72&#37;) out of 29 patients. CONCLUSIONS: In cerebral infarction limited to the internal capsule and/or corona radiata, PD is derived from smaller and left-sided lesions with delay in diagnosis compared with DFP. The clinical course of those with PD and DFP might be benign.

DOI： 10.1186/s12883-015-0439-5

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Aim Although many neuroimaging studies of obsessive-compulsive disorder (OCD) have reported broad abnormalities in gray matter (GM), their results remain inconsistent. One reason for this inconsistency could be the heterogeneity of OCD. In the present study, we aimed to classify alterations in brain anatomy by OCD subtype. Methods Magnetic resonance imaging examinations of 37 OCD patients and 37 matched healthy controls were conducted using a 3.0-Tesla scanner. In the voxel-based morphometric procedure, preprocessed GM structural images were used to compare the two groups, and multiple regression analysis was used to investigate the correlation between regional GM volume in OCD patients and the OCD symptom dimension type assessed by using the Dimensional Yale-Brown Obsessive-Compulsive Scale. Results We found significant reductions in GM volume in broad areas of the left prefrontal, right orbitofrontal, right parietal, right temporal, and right posterior cingulate cortex in the OCD patients compared to healthy controls. In addition, we found specific negative correlations between symptomatic dimension scores and regional GM volumes, mainly as decreased right cerebellum in 'aggression/checking' and decreased right insula in 'contamination/washing'. Conclusion The pathophysiology of OCD may involve widely distributed neural systems. Moreover, there are distinct correlations among symptomatic dimensions and structural abnormalities.

DOI： 10.1111/pcn.12269

記述言語：英語   掲載種別：研究論文（学術雑誌）  

AIM: Although many neuroimaging studies of obsessive-compulsive disorder (OCD) have reported broad abnormalities in gray matter (GM), their results remain inconsistent. One reason for this inconsistency could be the heterogeneity of OCD. In the present study, we aimed to classify alterations in brain anatomy by OCD subtype. METHODS: Magnetic resonance imaging examinations of 37 OCD patients and 37 matched healthy controls were conducted using a 3.0-Tesla scanner. In the voxel-based morphometric procedure, preprocessed GM structural images were used to compare the two groups, and multiple regression analysis was used to investigate the correlation between regional GM volume in OCD patients and the OCD symptom dimension type assessed by using the Dimensional Yale-Brown Obsessive-Compulsive Scale. RESULTS: We found significant reductions in GM volume in broad areas of the left prefrontal, right orbitofrontal, right parietal, right temporal, and right posterior cingulate cortex in the OCD patients compared to healthy controls. In addition, we found specific negative correlations between symptomatic dimension scores and regional GM volumes, mainly as decreased right cerebellum in 'aggression/checking' and decreased right insula in 'contamination/washing'. CONCLUSION: The pathophysiology of OCD may involve widely distributed neural systems. Moreover, there are distinct correlations among symptomatic dimensions and structural abnormalities.

DOI： 10.1111/pcn.12269

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: Volume isotropic simultaneous interleaved bright- and black-blood examination (VISIBLE) is a recently developed 3D MR sequence that provides simultaneous acquisitions of images with blood vessel suppression (Black) and images without it (Bright). Our purpose was to evaluate the usefulness of VISIBLE in detecting brain metastases. METHODS: This prospective study included patients with suspected brain metastasis imaged with both VISIBLE and MPRAGE. From a data set, we compared the number of visualized blood vessels and the lesion-to-normal contrast-to-noise ratio (CNR) in 60 patients. We also performed an observer test to compare their diagnostic performance with VISIBLE, MPRAGE and only Black in 34 patients. Diagnostic performance was evaluated using a figure of merit (FOM), sensitivity, false-positive results per case (FPs/case) and reading time. RESULTS: The number of vessels was significantly fewer in Black compared to MPRAGE and Bright (P < 0.0001). CNR was significantly higher with both Black and Bright than with MPRAGE (P < 0.005). In the observer test, significantly higher sensitivity (P < 0.0001) and FOM (P < 0.0001), significantly shorter reading time (P = 0.0001) and similar FPs/case were achieved with VISIBLE compared to MPRAGE. Compared to only Black, VISIBLE resulted in comparable sensitivity, but significantly fewer FPs/case (P = 0.0008). CONCLUSION: VISIBLE can improve radiologists' diagnostic performance for brain metastasis. KEY POINTS: • VISIBLE can achieve higher sensitivity and shorter reading time than MPRAGE. • VISIBLE can achieve lower false-positive rates than blood vessel suppressed images. • Compared to MPRAGE, VISIBLE can improve diagnostic performance for brain metastasis.

DOI： 10.1007/s00330-014-3496-z

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objective: Volume isotropic simultaneous interleaved bright- and black-blood examination (VISIBLE) is a recently developed 3D MR sequence that provides simultaneous acquisitions of images with blood vessel suppression (Black) and images without it (Bright). Our purpose was to evaluate the usefulness of VISIBLE in detecting brain metastases.Methods: This prospective study included patients with suspected brain metastasis imaged with both VISIBLE and MPRAGE. From a data set, we compared the number of visualized blood vessels and the lesion-to-normal contrast-to-noise ratio (CNR) in 60 patients. We also performed an observer test to compare their diagnostic performance with VISIBLE, MPRAGE and only Black in 34 patients. Diagnostic performance was evaluated using a figure of merit (FOM), sensitivity, false-positive results per case (FPs/case) and reading time.Results: The number of vessels was significantly fewer in Black compared to MPRAGE and Bright (P < 0.0001). CNR was significantly higher with both Black and Bright than with MPRAGE (P < 0.005). In the observer test, significantly higher sensitivity (P < 0.0001) and FOM (P < 0.0001), significantly shorter reading time (P = 0.0001) and similar FPs/case were achieved with VISIBLE compared to MPRAGE. Compared to only Black, VISIBLE resulted in comparable sensitivity, but significantly fewer FPs/case (P = 0.0008).Conclusion: VISIBLE can improve radiologists’ diagnostic performance for brain metastasis.Key Points: • VISIBLE can achieve higher sensitivity and shorter reading time than MPRAGE.• VISIBLE can achieve lower false-positive rates than blood vessel suppressed images.• Compared to MPRAGE, VISIBLE can improve diagnostic performance for brain metastasis.

DOI： 10.1007/s00330-014-3496-z

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

The recent development in magnetic resonance(MR)hardware and techniques allows the acquisition of functional information, such as perfusion or metabolism, in addition to conventional anatomical information in of cancers.In this review article, various molecular imaging methods based on MR are introduced and their application and usefulness for diagnosis of cancer are discussed.Diffusion weighted image (DWI) is believed to correlate cell density and reflect malignancy of tumor. DWI has been widely used for the diagnosis and evaluation of responses to cancer treatment.Arterial spin labeling (ASL) allows acquisition of perfusion data without the use of any contrast agent and is expected to be an alternative or complementary method to dynamic contrast enhanced MR imaging.Amide proton transfer (APT) imaging reflects the amount of mobile peptide and proteins in cancer tissue, and could be a useful tool for assessing tumor malignancy or evaluating treatment responses.More specific measurement of cancer metabolites is available at the cost of spatial resolution by MR spectroscopy (MRS). Finally, the positron emission tomography (PET)/MR hybrid system enables simultaneous acquisition of functional/ anatomical information from MR imaging and molecular/metabolic information from PET imaging.Combining various molecular MR imaging methods with PET tracers may have a huge potential for clinical diagnosis of cancer.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The recent development in magnetic resonance (MR) hardware and techniques allows the acquisition of functional information, such as perfusion or metabolism, in addition to conventional anatomical information in of cancers. In this review article, various molecular imaging methods based on MR are introduced and their application and usefulness for diagnosis of cancer are discussed. Diffusion weighted image (DWI) is believed to correlate cell density and reflect malignancy of tumor DWI has been widely used for the diagnosis and evaluation of responses to cancer treatment. Arterial spin labeling (ASL) allows acquisition of perfusion data without the use of any contrast agent and is expected to be an alternative or complementary method to dynamic contrast enhanced MR imaging. Amide proton transfer (APT) imaging reflects the amount of mobile peptide and proteins in cancer tissue, and could be a useful tool for assessing tumor malignancy or evaluating treatment responses. More specific measurement of cancer metabolites is available at the cost of spatial resolution by MR spectroscopy (MRS). Finally, the positron emission tomography (PET)/MR hybrid system enables simultaneous acquisition of functional/ anatomical information from MR imaging and molecular/metabolic information from PET imaging. Combining various molecular MR imaging methods with PET tracers may have a huge potential for clinical diagnosis of cancer.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Bone density measurements using high-resolution CT have been reported to be useful to diagnose fenestral otosclerosis. However, small region of interest (ROI) chosen by less-experienced radiologists may result in false-negative findings. Semi-automatic analysis such as CT histogram analysis may offer improved assessment. The aim of this study was to evaluate the utility of CT histogram analysis in diagnosing fenestral otosclerosis. Temporal bone CT of consecutive patients with otosclerosis and normal controls was retrospectively analyzed. The control group consisted of the normal-hearing contralateral ears of patients with otitis media, cholesteatoma, trauma, facial nerve palsy, or tinnitus. All CT images were obtained using a 64-detector-row CT scanner with 0.5-mm collimation. AROI encompassing 10 × 10 pixels was placed in the bony labyrinth located anterior to the oval window. The mean CT value, variance and entropy were compared between otosclerosis patients and normal controls using Student's t test. The number of pixels below mean minus SD in the control (&#37;Lowcont) and total subjects (&#37;Lowtotal) were also compared. In addition, the area under the receiver operating characteristic curves (AUC) value for the discrimination between otosclerosis patients and normal controls was calculated. 51 temporal bones of 38 patients with otosclerosis and 30 temporal bones of 30 control subjects were included. The mean CT value was significantly lower in otosclerosis cases than in normal controls (p < 0.01). In addition, variance, entropy, &#37;Lowcont and &#37;Lowtotal were significantly higher in otosclerosis cases than in normal controls (p < 0.01, respectively). The AUC values for the mean CT value, &#37;Lowcont and &#37;Lowtotal were 0.751, 0.760 and 0.765, respectively. In conclusion, our results demonstrated that histogram analysis of CT image may be of clinical value in diagnosing otosclerosis.

DOI： 10.1007/s00405-014-2933-6

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objective: We report the clinical application of intravoxel incoherent motion (IVIM) magnetic resonance (MR) imaging to diagnose a case of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) in the acute phase. Results: On IVIM MR Images of this patient, higher perfusion (f) and diffusion (D) values in the left occipital and temporal lobes were found compared to the contralateral areas. Conclusion: These findings imply a breakdown of autoregulation with hyperperfusion and vasogenic edema during the acute phase of MELAS, as described in previous reports. IVIM imaging is a valuable, noninvasive tool that simultaneously quantifies perfusion and diffusion parameters.

DOI： 10.1002/brb3.282

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s00062-013-0254-6

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To evaluate the diagnostic performance of a double-dose administration of gadolinium for brain metastases at 3 T in a systematic observer test. MATERIALS AND METHODS: Postcontrast MR images of 39 patients (total 104 metastases) were obtained by 3D T1-weighted sequences with both standard and cumulative double dose contrast administration. An observer test involving 9 radiologists (5 board-certified radiologists and 4 residents) was performed, and their diagnostic performance with the two doses was compared by means of sensitivity, false-positives, reading time, and a figure-of-merit. RESULTS: Compared to the standard dose, the double dose showed higher sensitivity (P < 0.0001), higher false-positive/case (P < 0.05), longer reading time (P < 0.05), and higher figure-of-merit (P < 0.0001). Particularly in small lesions (< 5 mm), sensitivity with the double dose (61.5&#37;, P < 0.0001) was approximately twice as high as that with the standard dose (29.5&#37;). Artifacts and blood vessels were the most common imaging findings resulting in false-positives. CONCLUSIONS: The double dose improved detection for metastases smaller than 5 mm at 3 T and thus resulted in better diagnostic performance of radiologists. However, a higher dose might result in prolonged reading time and increased false-positives, presumably due to increased vessel signals and frequency of flow-related artifacts.

DOI： 10.1007/s11604-014-0342-9

記述言語：英語   掲載種別：研究論文（学術雑誌）  

We introduced and optimized a novel sequence of fast (about 4min), volumetric, high resolution, simultaneous bright- and black-blood imaging with sufficient T₁ contrast between enhanced metastasis and surrounding brain parenchyma for their differentiation. This proposed sequence can be used for 3-dimensional volumetric T₁-weighted bright- and black-blood imaging in contrast-enhanced studies and may be promising for detecting small brain metastases by improving differentiation between blood vessels and small brain metastases.

DOI： 10.2463/mrms.2013-0065

記述言語：英語   掲載種別：研究論文（学術雑誌）  

AIM: To reveal angiographic findings to predict the result of balloon test occlusion (BTO). METHODS: The cerebral angiograms of 42 consecutive patients who underwent cerebral angiography including both the Matas and Allcock maneuvers and BTO were retrospectively analyzed. Visualization of the anterior cerebral artery (ACA) and the middle cerebral artery (MCA) by the cross flow on the tested side during the Matas or Allcock maneuver was graded on a 5-point scale. Circle of Willis (COW) anatomy with respect to the presence/absence of a collateral path to reach the tested internal carotid artery (ICA) was classified into four categories. A univariate logistic analysis was used to analyze the associations between each angiographic finding and the BTO result. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for each finding were calculated. RESULTS: Five patients (12&#37;) were BTO-positive and the remaining 37 patients (88&#37;) were BTO-negative. Visualizations of the ACA and MCA as well as the COW anatomy were significantly associated with the BTO result (P = 0.0051 for ACA, P = 0.0002 for MCA, and P < 0.0001 for COW anatomy). In particular, good MCA visualization and the presence of an anterior connection (collateral path to the tested ICA from the contralateral ICA via the anterior communicating artery) in the COW were highly predictive for negative BTO (negative predictive value = 100&#37; for both). CONCLUSION: A BTO result may be predicted by angiographic findings including ACA/MCA visualization and COW anatomy.

DOI： 10.4329/wjr.v6.i8.619

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.neures.2010.12.008

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BackgroundAmide proton transfer (APT) imaging is a novel molecular MRI technique to detect endogenous mobile proteins and peptides through chemical exchange saturation transfer. We prospectively assessed the usefulness of APT imaging in predicting the histological grade of adult diffuse gliomas.MethodsThirty-six consecutive patients with histopathologically proven diffuse glioma (48.1 ± 14.7 y old, 16 males and 20 females) were included in the study. APT MRI was conducted on a 3T clinical scanner and was obtained with 2 s saturation at 25 saturation frequency offsets ω =-6 to +6 ppm (step 0.5 ppm). δB₀ maps were acquired separately for a point-by-point δB₀ correction. APT signal intensity (SI) was defined as magnetization transfer asymmetry at 3.5 ppm: magnetization transfer ratio (MTR)_asym = (S_{[-3.5 ppm]}-S _{[+3.5 ppm]})/S₀. Regions of interest were carefully placed by 2 neuroradiologists in solid parts within brain tumors. The APT SI was compared with World Health Organization grade, Ki-67 labeling index (LI), and cell density.ResultsThe mean APT SI values were 2.1 ± 0.4% in grade II gliomas (n = 8), 3.2 ± 0.9% in grade III gliomas (n = 10), and 4.1 ± 1.0% in grade IV gliomas (n = 18). Significant differences in APT intensity were observed between grades II and III (P <. 05) and grades III and IV (P <. 05), as well as between grades II and IV (P <. 001). There were positive correlations between APT SI and Ki-67 LI (P =. 01, R = 0.43) and between APT SI and cell density (P <. 05, R = 0.38). The gliomas with microscopic necrosis showed higher APT SI than those without necrosis (P <. 001).ConclusionsAPT imaging can predict the histopathological grades of adult diffuse gliomas.

DOI： 10.1093/neuonc/not158

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Glioblastoma multiforme (GBM), which account for more than 50&#37; of all gliomas, is among the deadliest of all human cancers. Given the dismal prognosis of GBM, it would be advantageous to identify early biomarkers of a response to therapy to avoid continuing ineffective treatments and to initiate other therapeutic strategies. The present in vivo longitudinal study in an orthotopic mouse model demonstrates quantitative assessment of early treatment response during short-term chemotherapy with temozolomide (TMZ) by amide proton transfer (APT) imaging. In a GBM line, only one course of TMZ (3 d exposure and 4 d rest) at a dose of 80 mg/kg resulted in substantial reduction in APT signal compared with untreated control animals, in which the APT signal continued to increase. Although there were no detectable differences in tumor volume, cell density, or apoptosis rate between groups, levels of Ki67 (index of cell proliferation) were substantially reduced in treated tumors. In another TMZ-resistant GBM line, the APT signal and levels of Ki67 increased despite the same course of TMZ treatment. As metabolite changes are known to occur early in the time course of chemotherapy and precede morphologic changes, these results suggest that the APT signal in glioma may be a useful functional biomarker of treatment response or degree of tumor progression. Thus, APT imaging may serve as a sensitive biomarker of early treatment response and could potentially replace invasive biopsies to provide a definitive diagnosis. This would have a major impact on the clinical management of patients with glioma.

DOI： 10.1073/pnas.1323855111

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVES: 3D turbo field echo with diffusion-sensitised driven-equilibrium preparation (DSDE-TFE) is a novel non-echo planar technique for diffusion-weighted (DW) imaging. The purpose of this study was to differentiate intraorbital lymphoma from immunoglobulin G4-related disease (IgG4-RD) using the apparent diffusion coefficient (ADC) derived from DSDE-TFE. METHODS: Fifteen patients with lymphomas and 8 with IgG4-RDs underwent imaging. ADC and signal intensities compared with normal grey matter on T1-weighted images, fat-suppressed T2-weighted images and fat-suppressed postcontrast T1-weighted images were measured. Statistical analyses were performed using the Mann-Whitney U test and receiver operating characteristic (ROC) analysis. RESULTS: Intraorbital lesions were clearly visualised on DSDE-TFE without obvious geometrical distortion. The ADC of lymphoma (1.25 ± 0.50 × 10(-3) mm(2)/s; mean ± standard deviation) was significantly lower than that of IgG4-RD (1.67 ± 0.84 × 10(-3) mm(2)/s; P < 0.05). Conventional sequences could not separate lymphoma from IgG4-RD (0.93 ± 0.18 vs. 0.94 ± 0.21 on T1-weighted images, 0.92 ± 0.17 vs. 0.95 ± 0.14 on T2-weighted images and 2.03 ± 0.35 vs. 2.30 ± 0.58 on postcontrast T1-weighted images, for lymphoma and IgG4-RD, respectively; P > 0.05). ROC analysis showed the best diagnostic performance with ADC. CONCLUSION: The apparent diffusion coefficient derived from diffusion-sensitised driven-equilibrium preparation techniques may help to differentiate lymphoma from immunoglobulin G4-related disease. KEY POINTS: • Distinguishing between orbital lymphoma and immunoglobulin G4-related disease can be difficult • Intraorbital lesions were clearly visualised on diffusion-sensitised driven-equilibrium preparation magnetic resonance techniques. • Variations in field homogeneity do not affect DSDE-TFE techniques all that much. • ADCs derived from DSDE-TFE may help differentiate lymphoma from IgG4-RD.

DOI： 10.1007/s00330-013-3058-9

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Amide proton transfer (APT) imaging is a novel molecular MRI technique to detect endogenous mobile proteins and peptides through chemical exchange saturation transfer. We prospectively assessed the usefulness of APT imaging in predicting the histological grade of adult diffuse gliomas. METHODS: Thirty-six consecutive patients with histopathologically proven diffuse glioma (48.1 ± 14.7 y old, 16 males and 20 females) were included in the study. APT MRI was conducted on a 3T clinical scanner and was obtained with 2 s saturation at 25 saturation frequency offsets ω = -6 to +6 ppm (step 0.5 ppm). δB0 maps were acquired separately for a point-by-point δB0 correction. APT signal intensity (SI) was defined as magnetization transfer asymmetry at 3.5 ppm: magnetization transfer ratio (MTR)asym = (S[-3.5 ppm] - S[+3.5 ppm])/S0. Regions of interest were carefully placed by 2 neuroradiologists in solid parts within brain tumors. The APT SI was compared with World Health Organization grade, Ki-67 labeling index (LI), and cell density. RESULTS: The mean APT SI values were 2.1 ± 0.4&#37; in grade II gliomas (n = 8), 3.2 ± 0.9&#37; in grade III gliomas (n = 10), and 4.1 ± 1.0&#37; in grade IV gliomas (n = 18). Significant differences in APT intensity were observed between grades II and III (P < .05) and grades III and IV (P < .05), as well as between grades II and IV (P < .001). There were positive correlations between APT SI and Ki-67 LI (P = .01, R = 0.43) and between APT SI and cell density (P < .05, R = 0.38). The gliomas with microscopic necrosis showed higher APT SI than those without necrosis (P < .001). CONCLUSIONS: APT imaging can predict the histopathological grades of adult diffuse gliomas.

DOI： 10.1093/neuonc/not158

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Glioblastoma multiforme (GBM), which account for more than 50% of all gliomas, is among the deadliest of all human cancers. Given the dismal prognosis of GBM, it would be advantageous to identify early biomarkers of a response to therapy to avoid continuing ineffective treatments and to initiate other therapeutic strategies. The present in vivo longitudinal study in an orthotopic mouse model demonstrates quantitative assessment of early treatment response during short-term chemotherapy with temozolomide (TMZ) by amide proton transfer (APT) imaging. In a GBM line, only one course of TMZ (3 d exposure and 4 d rest) at a dose of 80 mg/kg resulted in substantial reduction in APT signal compared with untreated control animals, in which the APT signal continued to increase. Although there were no detectable differences in tumor volume, cell density, or apoptosis rate between groups, levels of Ki67 (index of cell proliferation) were substantially reduced in treated tumors. In another TMZ-resistant GBM line, the APT signal and levels of Ki67 increased despite the same course of TMZ treatment. As metabolite changes are known to occur early in the time course of chemotherapy and precede morphologic changes, these results suggest that the APT signal in glioma may be a useful functional biomarker of treatment response or degree of tumor progression. Thus, APT imaging may serve as a sensitive biomarker of early treatment response and could potentially replace invasive biopsies to provide a definitive diagnosis. This would have a major impact on the clinical management of patients with glioma.

DOI： 10.1073/pnas.1323855111

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objectives: 3D turbo field echo with diffusion-sensitised driven-equilibrium preparation (DSDE-TFE) is a novel non-echo planar technique for diffusion-weighted (DW) imaging. The purpose of this study was to differentiate intraorbital lymphoma from immunoglobulin G4-related disease (IgG4-RD) using the apparent diffusion coefficient (ADC) derived from DSDE-TFE. Methods: Fifteen patients with lymphomas and 8 with IgG4-RDs underwent imaging. ADC and signal intensities compared with normal grey matter on T1-weighted images, fat-suppressed T2-weighted images and fat-suppressed postcontrast T1-weighted images were measured. Statistical analyses were performed using the Mann-Whitney U test and receiver operating characteristic (ROC) analysis. Results: Intraorbital lesions were clearly visualised on DSDE-TFE without obvious geometrical distortion. The ADC of lymphoma (1.25 ± 0.50 × 10^-3 mm²/s; mean ± standard deviation) was significantly lower than that of IgG4-RD (1.67 ± 0.84 × 10 ^-3 mm²/s; P < 0.05). Conventional sequences could not separate lymphoma from IgG4-RD (0.93 ± 0.18 vs. 0.94 ± 0.21 on T1-weighted images, 0.92 ± 0.17 vs. 0.95 ± 0.14 on T2-weighted images and 2.03 ± 0.35 vs. 2.30 ± 0.58 on postcontrast T1-weighted images, for lymphoma and IgG4-RD, respectively; P > 0.05). ROC analysis showed the best diagnostic performance with ADC. Conclusion: The apparent diffusion coefficient derived from diffusion-sensitised driven-equilibrium preparation techniques may help to differentiate lymphoma from immunoglobulin G4-related disease. Key Points: • Distinguishing between orbital lymphoma and immunoglobulin G4-related disease can be difficult • Intraorbital lesions were clearly visualised on diffusion-sensitised driven-equilibrium preparation magnetic resonance techniques. • Variations in field homogeneity do not affect DSDE-TFE techniques all that much. • ADCs derived from DSDE-TFE may help differentiate lymphoma from IgG4-RD.

DOI： 10.1007/s00330-013-3058-9

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To evaluate the diagnostic performance of a double-dose administration of gadolinium for brain metastases at 3 T in a systematic observer test. Materials and Methods: Postcontrast MR images of 39 patients (total 104 metastases) were obtained by 3D T1-weighted sequences with both standard and cumulative double dose contrast administration. An observer test involving 9 radiologists (5 board-certified radiologists and 4 residents) was performed, and their diagnostic performance with the two doses was compared by means of sensitivity, false-positives, reading time, and a figure-of-merit. Results: Compared to the standard dose, the double dose showed higher sensitivity (P < 0.0001), higher false-positive/case (P < 0.05), longer reading time (P < 0.05), and higher figure-of-merit (P < 0.0001). Particularly in small lesions (<5 mm), sensitivity with the double dose (61.5 %, P < 0.0001) was approximately twice as high as that with the standard dose (29.5 %). Artifacts and blood vessels were the most common imaging findings resulting in false-positives. Conclusions: The double dose improved detection for metastases smaller than 5 mm at 3 T and thus resulted in better diagnostic performance of radiologists. However, a higher dose might result in prolonged reading time and increased false-positives, presumably due to increased vessel signals and frequency of flow-related artifacts.

DOI： 10.1007/s11604-014-0342-9

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Percutaneous vertebroplasty (PVP) is a minimally invasive procedure that provides pain relief and stability for osteoporotic compression fractures. Balloon kyphoplasty (BKP) is a modification of PVP in which expandable balloons are used to restore height and to create a void in vertebra before cement injection. There are several studies regarding PVP/BKP vs. sham procedures and conservative treatment In this article we review recent studies and introduce some ongoing research.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Bone density measurements using high-resolution CT have been reported to be useful to diagnose fenestral otosclerosis. However, small region of interest (ROI) chosen by less-experienced radiologists may result in false-negative findings. Semi-automatic analysis such as CT histogram analysis may offer improved assessment. The aim of this study was to evaluate the utility of CT histogram analysis in diagnosing fenestral otosclerosis. Temporal bone CT of consecutive patients with otosclerosis and normal controls was retrospectively analyzed. The control group consisted of the normal-hearing contralateral ears of patients with otitis media, cholesteatoma, trauma, facial nerve palsy, or tinnitus. All CT images were obtained using a 64-detector-row CT scanner with 0.5-mm collimation. AROI encompassing 10 × 10 pixels was placed in the bony labyrinth located anterior to the oval window. The mean CT value, variance and entropy were compared between otosclerosis patients and normal controls using Student’s t test. The number of pixels below mean minus SD in the control (%Low_cont) and total subjects (%Low_total) were also compared. In addition, the area under the receiver operating characteristic curves (AUC) value for the discrimination between otosclerosis patients and normal controls was calculated. 51 temporal bones of 38 patients with otosclerosis and 30 temporal bones of 30 control subjects were included. The mean CT value was significantly lower in otosclerosis cases than in normal controls (p < 0.01). In addition, variance, entropy, %Low_cont and %Low_total were significantly higher in otosclerosis cases than in normal controls (p < 0.01, respectively). The AUC values for the mean CT value, %Low_cont and %Low_total were 0.751, 0.760 and 0.765, respectively. In conclusion, our results demonstrated that histogram analysis of CT image may be of clinical value in diagnosing otosclerosis.

DOI： 10.1007/s00405-014-2933-6

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND AND PURPOSE: 3D turbo field echo with diffusion-sensitized driven-equilibrium preparation is a non-echo-planar technique for DWI, which enables high-resolution DWI without field inhomogeneity-related image distortion. The purpose of this study was to evaluate the feasibility of diffusion-sensitized driven-equilibrium turbo field echo in evaluating diffusivity in the normal pituitary gland. MATERIALS AND METHODS: First, validation of diffusion-sensitized driven-equilibrium turbo field echo was attempted by comparing it with echo-planar DWI. Five healthy volunteers were imaged by using diffusion-sensitized driven-equilibrium turbo field echo and echoplanar DWI. The imaging voxel size was 1.5 x 1.5 x 1.5 mm³ for diffusion-sensitized driven-equilibrium turbo field echo and 1.5 x 1.9 x 3.0 mm³ for echo-planar DWI. ADCs measured by the 2 methods in 15 regions of interests (6 in gray matter and 9 in white matter) were compared by using the Pearson correlation coefficient. The ADC in the pituitary anterior lobe was then measured in 10 volunteers by using diffusion-sensitized driven-equilibrium turbo field echo, and the results were compared with those in the pons and vermis by using a paired t test. RESULTS: The ADCs from the 2 methods showed a strong correlation (r = 0.79; P < .0001), confirming the accuracy of the ADC measurement with the diffusion-sensitized driven-equilibrium sequence. The ADCs in the normal pituitary gland were 1.37 ± 0.13 x 10^-3 mm ²/s, which were significantly higher than those in the pons (1.01 ± 0.24 x 10^-3mm²/s) and the vermis (0.89 ± 0.25 x 10^-3 mm²/s, P < .01). CONCLUSIONS: We demonstrated that diffusion-sensitized driven-equilibrium turbo field echo is feasible in assessing ADC in the pituitary gland.

DOI： 10.3174/ajnr.A3620

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Background: Loeys-Dietz syndrome, also known as Marfan syndrome type II, is a rare connective tissue disorder caused by dominant mutations in transforming growth factor-beta receptors (TGFBR1 and 2). Case presentation. We report a 7-year-old Japanese boy with Loeys-Dietz syndrome who carried a novel, de novo missense mutation in TGFBR2 (c.1142g > c, R381P). He showed dysmorphic faces and skeletal malformations that were typical in previous cases with Loeys-Dietz syndrome. The cardiac studies disclosed the presence of markedly dilated aortic root and patent ductus aorteriosus. The cranial magnetic resonance imaging (MRI) and angiography (MRA) detected the tortuous appearances of the bilateral middle cerebral and carotid arteries. Conclusion: This study depicts the systemic vascular phenotypes of a child with Loeys-Dietz syndrome that were caused by a novel heterozygous mutation of TGFR2. A large cohort with serial imaging studies for vascular phenotypes will be useful for delineating the genotype-phenotype correlations of Loeys-Dietz syndrome.

DOI： 10.1186/1756-0500-6-456

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Loeys-Dietz syndrome, also known as Marfan syndrome type II, is a rare connective tissue disorder caused by dominant mutations in transforming growth factor-beta receptors (TGFBR1 and 2). CASE PRESENTATION: We report a 7-year-old Japanese boy with Loeys-Dietz syndrome who carried a novel, de novo missense mutation in TGFBR2 (c.1142g > c, R381P). He showed dysmorphic faces and skeletal malformations that were typical in previous cases with Loeys-Dietz syndrome. The cardiac studies disclosed the presence of markedly dilated aortic root and patent ductus aorteriosus. The cranial magnetic resonance imaging (MRI) and angiography (MRA) detected the tortuous appearances of the bilateral middle cerebral and carotid arteries. CONCLUSION: This study depicts the systemic vascular phenotypes of a child with Loeys-Dietz syndrome that were caused by a novel heterozygous mutation of TGFR2. A large cohort with serial imaging studies for vascular phenotypes will be useful for delineating the genotype-phenotype correlations of Loeys-Dietz syndrome.

DOI： 10.1186/1756-0500-6-456

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Amide proton transfer (APT) imaging is one of the chemical exchange saturation transfer (CEST) imaging methods which images the exchange between protons of free tissue water and the amide groups (-NH) of endogenous mobile proteins and peptides. Previous work suggested the ability of APT imaging for characterization of the tumoral grade in the brain tumor. In this study, we tested the feasibility of in-vivo APT imaging of lung tumor and investigated whether the method could differentiate the tumoral types on orthotopic tumor xenografts from two malignant lung cancer cell lines. The results revealed that APT imaging is feasible to quantify lung tumors in the moving lung. The measured APT effect was higher in the tumor which exhibited more active proliferation than the other. The present study demonstrates that APT imaging has the potential to provide a characterization test to differentiate types or grade of lung cancer noninvasively, which may eventually reduce the need invasive needle biopsy or resection for lung cancer.

DOI： 10.1371/journal.pone.0077019

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Objective To prospectively evaluate the usefulness of a newly developed high-resolution three-dimensional diffusion-weighted imaging method, turbo field-echo with diffusion-sensitized driven-equilibrium (TFE-DSDE) in diagnosing middle-ear cholesteatoma by comparing it to conventional single-shot echo-planar diffusion-weighted imaging (SS-EP DWI). Materials and methods Institutional review board approval and informed consent from all participants were obtained. We studied 30 patients with preoperatively suspected acquired cholesteatoma. Each patient underwent an MR examination including both SS-EP DWI and DSDE-TFE using a 3.0 T MR scanner. Images of the 30 patients (60 temporal bones including 30 with and 30 without cholesteatoma) were reviewed by two independent neuroradiologists. The confidence level for the presence of cholesteatoma was graded on a scale of 0-2 (0 = definite absence, 1 = equivocal, 2 = definite presence). Interobserver agreement as well as sensitivity, specificity, and accuracy for detection were assessed for the two reviewers. Results Excellent interobserver agreement was shown for TFE-DSDE (κ = 0.821) whereas fair agreement was obtained for SS-EP DWI (κ = 0.416). TFE-DSDE was associated with significantly higher sensitivity (83.3%) and accuracy (90.0%) compared to SS-EP DWI (sensitivity = 35.0%, accuracy = 66.7%; p < 0.05). No significant difference was found in specificity (96.7% for TFE-DSDE, 98.3% for SS-EP DWI) Conclusion With increased spatial resolution and reduced susceptibility artifacts, TFE-DSDE improves the accuracy in diagnosing acquired middle ear cholesteatomas compared to SS-EP DWI.

DOI： 10.1016/j.ejrad.2013.04.018

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: To prospectively evaluate the usefulness of a newly developed high-resolution three-dimensional diffusion-weighted imaging method, turbo field-echo with diffusion-sensitized driven-equilibrium (TFE-DSDE) in diagnosing middle-ear cholesteatoma by comparing it to conventional single-shot echo-planar diffusion-weighted imaging (SS-EP DWI). MATERIALS AND METHODS: Institutional review board approval and informed consent from all participants were obtained. We studied 30 patients with preoperatively suspected acquired cholesteatoma. Each patient underwent an MR examination including both SS-EP DWI and DSDE-TFE using a 3.0 T MR scanner. Images of the 30 patients (60 temporal bones including 30 with and 30 without cholesteatoma) were reviewed by two independent neuroradiologists. The confidence level for the presence of cholesteatoma was graded on a scale of 0-2 (0=definite absence, 1=equivocal, 2=definite presence). Interobserver agreement as well as sensitivity, specificity, and accuracy for detection were assessed for the two reviewers. RESULTS: Excellent interobserver agreement was shown for TFE-DSDE (κ=0.821) whereas fair agreement was obtained for SS-EP DWI (κ=0.416). TFE-DSDE was associated with significantly higher sensitivity (83.3&#37;) and accuracy (90.0&#37;) compared to SS-EP DWI (sensitivity=35.0&#37;, accuracy=66.7&#37;; p<0.05). No significant difference was found in specificity (96.7&#37; for TFE-DSDE, 98.3&#37; for SS-EP DWI) CONCLUSION: With increased spatial resolution and reduced susceptibility artifacts, TFE-DSDE improves the accuracy in diagnosing acquired middle ear cholesteatomas compared to SS-EP DWI.

DOI： 10.1016/j.ejrad.2013.04.018

記述言語：英語   掲載種別：研究論文（学術雑誌）  

We are the first to report a case that showed spontaneous resolution of epidural hematoma which was related to a steroid-induced osteoporotic compression fracture. The patient had a painful fracture with an intravertebral cleft at L1 accompanying an epidural hematoma posteriorly. Immediate pain relief was achieved after percutaneous vertebroplasty. Complete resolution of hematoma was noted three months after procedure. We theorized that intravertebral stability after treatment might have played a role in this patient.

DOI： 10.4329/wjr.v5.i8.325

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Imaging all the people: Using ionizable diblock copolymers a series of nanoprobes encoded with different ¹⁹F reporters for specific pH transitions is prepared for use in MRI. The pH response of the nanoprobes is extremely sharp (ΔpH_ON/OFF≈0.25 pH), and results from the disassembly of polymer micelles (see scheme). A collection of three nanoprobes provides the proof of concept and allows for a qualitative measurement of environmental pH values.

DOI： 10.1002/anie.201301135

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1002/anie.201301135

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Parkinson's disease (PD) reportedly includes altered connectivity of neural loops involving the basal ganglia and cerebellum, although little is known regarding any changes in the connectivity of motor loops. The goal of this study was to further understand the connectivity within the basal ganglia-thalamo-motor (BGTM) and cerebro-cerebellar (CC) loops in PD. Twelve PD patients and 12 age-matched control subjects performed a protocol involving self-initiated (SI) and externally-triggered (ET) finger movements, while being scanned with functional magnetic resonance imaging. Compared with the control subjects, the PD subjects showed hypo-activation in the bilateral putamen, right supplementary motor area and hyper-activation in the right premotor cortex. In the sensorimotor cortex and cerebellar hemisphere, PD subjects tended to show hyper-activation in a main effects analysis, but hypo-activation in a linear effects analysis. Analysis using structural equation modeling (SEM) revealed significant positive interactions within the right BGTM loop during the SI task and within the right (right cerebral hemisphere-left cerebellum) CC loop during the ET task. SEM also revealed task-related quantitative changes between the thalamus and the motor cortices in the control subjects. We found that the PD patients showed reduced connectivity in the right BGTM loop and inter-hemispheric connections in SEM, which is the first demonstration of this phenomenon. Interestingly, PD patients exhibited preserved connectivity within the right CC loop during the ET task. These results suggest disruption of cortico-striatal processing and preservation of relatively intact neural circuits that do not involve the basal ganglia in PD.

DOI： 10.1016/j.brainres.2013.03.027

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Parkinson's disease (PD) reportedly includes altered connectivity of neural loops involving the basal ganglia and cerebellum, although little is known regarding any changes in the connectivity of motor loops. The goal of this study was to further understand the connectivity within the basal ganglia-thalamo-motor (BGTM) and cerebro-cerebellar (CC) loops in PD. Twelve PD patients and 12 age-matched control subjects performed a protocol involving self-initiated (SI) and externally-triggered (ET) finger movements, while being scanned with functional magnetic resonance imaging. Compared with the control subjects, the PD subjects showed hypo-activation in the bilateral putamen, right supplementary motor area and hyper-activation in the right premotor cortex. In the sensorimotor cortex and cerebellar hemisphere, PD subjects tended to show hyper-activation in a main effects analysis, but hypo-activation in a linear effects analysis. Analysis using structural equation modeling (SEM) revealed significant positive interactions within the right BGTM loop during the SI task and within the right (right cerebral hemisphere-left cerebellum) CC loop during the ET task. SEM also revealed task-related quantitative changes between the thalamus and the motor cortices in the control subjects. We found that the PD patients showed reduced connectivity in the right BGTM loop and inter-hemispheric connections in SEM, which is the first demonstration of this phenomenon. Interestingly, PD patients exhibited preserved connectivity within the right CC loop during the ET task. These results suggest disruption of cortico-striatal processing and preservation of relatively intact neural circuits that do not involve the basal ganglia in PD.

DOI： 10.1016/j.brainres.2013.03.027

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Background: Heterogeneity of arterial transit time due to cerebral artery steno-occlusive lesions hampers accurate regional cerebral blood flow measurement by arterial spin labeling (ASL). Purpose: To assess the feasibility of regional cerebral blood flow measurement by ASL with multiple-delay time sampling in patients with steno-occlusive diseases by comparing with positron emission tomography (PET), and to determine whether regional arterial transit time measured by this ASL technique is correlated with regional mean transit time, a PET index of perfusion pressure. Material and Methods: Sixteen patients with steno-occlusive diseases received both ASL and 15O-PET. The mean regional cerebral blood flow measured by ASL and PET, regional arterial transit time by ASL, and regional mean transit time by PET were obtained by a region-of-interest analysis. Correlation between regional cerebral blood flow by ASL and that by PET, and correlation between regional arterial transit time by ASL and regional mean transit time by PET were tested using Pearson's correlation coefficient for both absolute and relative values. A multivariate regression analysis was performed to test whether regional arterial transit time by ASL was a significant contributor in modeling regional mean transit time by PET after controlling the effect of regional cerebral blood flow by ASL. Results: A significant positive correlation was found between regional cerebral blood flow by ASL and that by PET for both absolute (r = 0.520, P < 0.0001) and relative (r = 0.691, P < 0.0001) values. A significant positive correlation was found between regional arterial transit time by ASL and regional mean transit time by PET both for absolute (r = 0.369, P = 0.0002) and relative (r = 0.443, P < 0.0001) values. The regression analysis revealed that regional arterial transit time by ASL was a significant contributor in modeling regional mean transit time by PET after controlling regional cerebral blood flow by ASL (P = 0.0011). Conclusion: The feasibility of regional cerebral blood flow measurement using ASL with multiple-delay time sampling was confirmed in patients with cerebral artery steno-occlusive diseases. Moreover, it was suggested that mapping of regional arterial transit time has the potential to detect hemodynamic impairment.

DOI： 10.1258/ar.2012.120450

記述言語：英語   掲載種別：研究論文（学術雑誌）  

INTRODUCTION: Our purpose was to evaluate the diagnostic performance of arterial spin labeling (ASL) perfusion imaging, diffusion-weighted imaging (DWI), and (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) in differentiating primary central nervous system lymphomas (PCNSLs) from glioblastoma multiformes (GBMs). METHODS: Fifty-six patients including 19 with PCNSL and 37 with GBM were retrospectively studied. From the ASL data, an absolute tumor blood flow (aTBF) and a relative tumor blood flow (rTBF) were obtained within the enhancing portion of each tumor. In addition, the minimum apparent diffusion coefficient (ADCmin) and the maximum standard uptake value (SUVmax) were obtained from DWI and FDG-PET data, respectively. Each of the four parameters was compared between PCNSLs and GBMs using Kruskal-Wallis test. The performance in discriminating between PCNSLs and GBMs was evaluated using the receiver-operating characteristics analysis. Area-under-the-curve (AUC) values were compared among the four parameters using a nonparametric method. RESULTS: The aTBF, rTBF, and ADCmin were significantly higher in GBMs (mean aTBF ± SD = 91.6 ± 56.0 mL/100 g/min, mean rTBF ± SD = 2.61 ± 1.61, mean ADCmin ± SD = 0.78 ± 0.19 × 10(-3) mm(2)/s) than in PCNSLs (mean aTBF ± SD = 37.3 ± 10.5 mL/100 g/min, mean rTBF ± SD = 1.24 ± 0.37, mean ADCmin ± SD = 0.61 ± 0.13 × 10(-3) mm(2)/s) (p < 0.005, respectively). In addition, SUVmax was significantly lower in GBMs (mean ± SD = 13.1 ± 6.34) than in PCNSLs (mean ± SD = 22.5 ± 7.83) (p < 0.005). The AUC for aTBF (0.888) was higher than those for rTBF (0.810), ADCmin (0.768), and SUVmax (0.848), although their difference was not statistically significant. CONCLUSION: ASL perfusion imaging is useful for differentiating PCNSLs from GBMs as well as DWI and FDG-PET.

DOI： 10.1007/s00234-012-1089-6

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Heterogeneity of arterial transit time due to cerebral artery steno-occlusive lesions hampers accurate regional cerebral blood flow measurement by arterial spin labeling (ASL). PURPOSE: To assess the feasibility of regional cerebral blood flow measurement by ASL with multiple-delay time sampling in patients with steno-occlusive diseases by comparing with positron emission tomography (PET), and to determine whether regional arterial transit time measured by this ASL technique is correlated with regional mean transit time, a PET index of perfusion pressure. MATERIAL AND METHODS: Sixteen patients with steno-occlusive diseases received both ASL and (15)O-PET. The mean regional cerebral blood flow measured by ASL and PET, regional arterial transit time by ASL, and regional mean transit time by PET were obtained by a region-of-interest analysis. Correlation between regional cerebral blood flow by ASL and that by PET, and correlation between regional arterial transit time by ASL and regional mean transit time by PET were tested using Pearson's correlation coefficient for both absolute and relative values. A multivariate regression analysis was performed to test whether regional arterial transit time by ASL was a significant contributor in modeling regional mean transit time by PET after controlling the effect of regional cerebral blood flow by ASL. RESULTS: A significant positive correlation was found between regional cerebral blood flow by ASL and that by PET for both absolute (r = 0.520, P < 0.0001) and relative (r = 0.691, P < 0.0001) values. A significant positive correlation was found between regional arterial transit time by ASL and regional mean transit time by PET both for absolute (r = 0.369, P = 0.0002) and relative (r = 0.443, P < 0.0001) values. The regression analysis revealed that regional arterial transit time by ASL was a significant contributor in modeling regional mean transit time by PET after controlling regional cerebral blood flow by ASL (P = 0.0011). CONCLUSION: The feasibility of regional cerebral blood flow measurement using ASL with multiple-delay time sampling was confirmed in patients with cerebral artery steno-occlusive diseases. Moreover, it was suggested that mapping of regional arterial transit time has the potential to detect hemodynamic impairment.

DOI： 10.1258/ar.2012.120450

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Introduction: Our purpose was to evaluate the diagnostic performance of arterial spin labeling (ASL) perfusion imaging, diffusion-weighted imaging (DWI), and ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) in differentiating primary central nervous system lymphomas (PCNSLs) from glioblastoma multiformes (GBMs). Methods: Fifty-six patients including 19 with PCNSL and 37 with GBM were retrospectively studied. From the ASL data, an absolute tumor blood flow (aTBF) and a relative tumor blood flow (rTBF) were obtained within the enhancing portion of each tumor. In addition, the minimum apparent diffusion coefficient (ADCmin) and the maximum standard uptake value (SUVmax) were obtained from DWI and FDG-PET data, respectively. Each of the four parameters was compared between PCNSLs and GBMs using Kruskal-Wallis test. The performance in discriminating between PCNSLs and GBMs was evaluated using the receiver-operating characteristics analysis. Area-under-the-curve (AUC) values were compared among the four parameters using a nonparametric method. Results: The aTBF, rTBF, and ADCmin were significantly higher in GBMs (mean aTBF ± SD = 91.6 ± 56.0 mL/100 g/min, mean rTBF ± SD = 2.61 ± 1.61, mean ADCmin ± SD = 0.78 ± 0.19 × 10^-3 mm²/s) than in PCNSLs (mean aTBF ± SD = 37.3 ± 10.5 mL/100 g/min, mean rTBF ± SD = 1.24 ± 0.37, mean ADCmin ± SD = 0.61 ± 0.13 × 10^-3 mm²/s) (p < 0.005, respectively). In addition, SUVmax was significantly lower in GBMs (mean ± SD = 13.1 ± 6.34) than in PCNSLs (mean ± SD = 22.5 ± 7.83) (p < 0.005). The AUC for aTBF (0.888) was higher than those for rTBF (0.810), ADCmin (0.768), and SUVmax (0.848), although their difference was not statistically significant. Conclusion: ASL perfusion imaging is useful for differentiating PCNSLs from GBMs as well as DWI and FDG-PET.

DOI： 10.1007/s00234-012-1089-6

記述言語：英語   掲載種別：研究論文（学術雑誌）  

It has been hypothesized that increased flux through the pentose phosphate pathway (PPP) is required to support the metabolic demands of rapid malignant cell growth. Using orthotopic mouse models of human glioblastoma (GBM) and renal cell carcinoma metastatic to brain, we estimated the activity of the PPP relative to glycolysis by infusing [1,2-¹³C₂]glucose. The [3-¹³C]lactate/[2,3-¹³C₂]lactate ratio was similar for both the GBM and brain metastasis and their respective surrounding brains (GBM, 0.197±0.011 and 0.195±0.033, respectively (p=1); metastasis: 0.126 and 0.119±0.033, respectively). This suggests that the rate of glycolysis is significantly greater than the PPP flux in these tumors, and that the PPP flux into the lactate pool is similar in both tumors. Remarkably, ¹³C-¹³C coupling was observed in molecules derived from Krebs cycle intermediates in both tumor types, denoting glucose oxidation. In the renal cell carcinoma, in contrast with GBM, ¹³C multiplets of γ-aminobutyric acid (GABA) differed from its precursor glutamate, suggesting that GABA did not derive from a common glutamate precursor pool. In addition, the orthotopic renal tumor, the patient's primary renal mass and brain metastasis were all strongly immunopositive for the 67-kDa isoform of glutamate decarboxylase, as were 84% of tumors on a renal cell carcinoma tissue microarray of the same histology, suggesting that GABA synthesis is cell autonomous in at least a subset of renal cell carcinomas. Taken together, these data demonstrate that ¹³C-labeled glucose can be used in orthotopic mouse models to study tumor metabolism in vivo and to ascertain new metabolic targets for cancer diagnosis and therapy.

DOI： 10.1002/nbm.2787

記述言語：英語   掲載種別：研究論文（学術雑誌）  

It has been hypothesized that increased flux through the pentose phosphate pathway (PPP) is required to support the metabolic demands of rapid malignant cell growth. Using orthotopic mouse models of human glioblastoma (GBM) and renal cell carcinoma metastatic to brain, we estimated the activity of the PPP relative to glycolysis by infusing [1,2-(13) C(2) ]glucose. The [3-(13) C]lactate/[2,3-(13) C(2) ]lactate ratio was similar for both the GBM and brain metastasis and their respective surrounding brains (GBM, 0.197 ± 0.011 and 0.195 ± 0.033, respectively (p = 1); metastasis: 0.126 and 0.119 ± 0.033, respectively). This suggests that the rate of glycolysis is significantly greater than the PPP flux in these tumors, and that the PPP flux into the lactate pool is similar in both tumors. Remarkably, (13) C-(13) C coupling was observed in molecules derived from Krebs cycle intermediates in both tumor types, denoting glucose oxidation. In the renal cell carcinoma, in contrast with GBM, (13) C multiplets of γ-aminobutyric acid (GABA) differed from its precursor glutamate, suggesting that GABA did not derive from a common glutamate precursor pool. In addition, the orthotopic renal tumor, the patient's primary renal mass and brain metastasis were all strongly immunopositive for the 67-kDa isoform of glutamate decarboxylase, as were 84&#37; of tumors on a renal cell carcinoma tissue microarray of the same histology, suggesting that GABA synthesis is cell autonomous in at least a subset of renal cell carcinomas. Taken together, these data demonstrate that (13) C-labeled glucose can be used in orthotopic mouse models to study tumor metabolism in vivo and to ascertain new metabolic targets for cancer diagnosis and therapy.

DOI： 10.1002/nbm.2787

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The exchange of water molecules between the inner sphere of a paramagnetic chemical exchange saturation transfer (PARACEST) contrast agent and bulk water can shorten the bulk water T₂ through the T₂-exchange (T_2ex) mechanism. The line-broadening T_2ex effect is proportional to the agent concentration, the chemical shift of the exchanging water molecule, and is highly dependent on the water molecule exchange rate. A significant T_2ex contribution to the bulk water linewidth can make the regions of agent uptake appear dark when imaging with conventional sequences like gradient-echo and fast spin-echo. The minimum echo times for these sequences (1-10 ms) are not fast enough to capture signal from the regions of shortened T₂. This makes "Off" (saturation at -ΔIω) minus "On" (saturation at +ΔIω) imaging of PARACEST agents difficult, because the regions of uptake are dark in both images. It is shown here that the loss of bulk water signal due to T _2ex can be reclaimed using the ultrashort echo times (<10 μs) achieved with the sweep imaging with Fourier transform pulse sequence. Modification of the sweep imaging with Fourier transform sequence for PARACEST imaging is first discussed, followed by parameter optimization using in vitro experiments. In vivo PARACEST studies comparing fast spin-echo to sweep imaging with Fourier transform were performed using EuDOTA-(gly) 4- uptake in healthy mouse kidneys. The results show that the negative contrast caused by T _2ex can be overcome using the ultrashort echo time achieved with sweep imaging with Fourier transform, thereby enabling fast and sensitive in vivo PARACEST imaging.

DOI： 10.1002/mrm.23302

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The exchange of water molecules between the inner sphere of a paramagnetic chemical exchange saturation transfer (PARACEST) contrast agent and bulk water can shorten the bulk water T(2) through the T(2) -exchange (T(2ex) ) mechanism. The line-broadening T(2ex) effect is proportional to the agent concentration, the chemical shift of the exchanging water molecule, and is highly dependent on the water molecule exchange rate. A significant T(2ex) contribution to the bulk water linewidth can make the regions of agent uptake appear dark when imaging with conventional sequences like gradient-echo and fast spin-echo. The minimum echo times for these sequences (1-10 ms) are not fast enough to capture signal from the regions of shortened T(2) . This makes "Off" (saturation at -Δω) minus "On" (saturation at +Δω) imaging of PARACEST agents difficult, because the regions of uptake are dark in both images. It is shown here that the loss of bulk water signal due to T(2ex) can be reclaimed using the ultrashort echo times (<10 μs) achieved with the sweep imaging with Fourier transform pulse sequence. Modification of the sweep imaging with Fourier transform sequence for PARACEST imaging is first discussed, followed by parameter optimization using in vitro experiments. In vivo PARACEST studies comparing fast spin-echo to sweep imaging with Fourier transform were performed using EuDOTA-(gly) 4- uptake in healthy mouse kidneys. The results show that the negative contrast caused by T(2ex) can be overcome using the ultrashort echo time achieved with sweep imaging with Fourier transform, thereby enabling fast and sensitive in vivo PARACEST imaging.

DOI： 10.1002/mrm.23302

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Introduction Hemangioblastoma and metastatic tumors are the major differential diagnoses for the posterior fossa tumors in adults. Our purpose was to evaluate the efficacy of ASL in differentiating hemangioblastomas from metastatic brain tumors. Methods A total of 19 patients including 5 with a hemangioblastomas and 14 with metastatic tumors (7 from lung cancer, 4 frombreast cancer, 1 fromRCC, 1 from gastric cancer, and 1 from unknown origin) were enrolled in this study. ASL was performed using a pulsed ASL method at a 3-T unit. aTBF was measured as a mean absolute blood flow value within a region of interest drawn in the tumor. In addition, rTBF was obtained by normalizing the aTBF by a blood flow measured in the normal-appearing cortical gray matter. The aTBF and rTBF values were compared between hemangioblastomas and metastatic tumors using Student's t test. Results Both the aTBF and rTBF values were significantly higher in hemangioblastomas (mean aTBF±SD=437± 274 mL/100 g/min, mean rTBF±SD=7.96±3.12) in comparison with metastatic brain tumors (mean aTBF±SD= 125±134 mL/100 g/min, mean rTBF±SD=2.98±3.91; P<0.05, respectively). However, a metastasis from RCC showed very high aTBF (559 mL/100 g/min) and rTBF (16.2). Conclusion Our results demonstrated that ASL provides useful information to differentiate between hemangioblastomas and metastatic brain tumors. Metastasis from RCC may mimic hemangioblastoma on ASL blood flow measurement.

DOI： 10.1007/s00234-011-0977-5

記述言語：英語   掲載種別：研究論文（学術雑誌）  

INTRODUCTION: Hemangioblastoma and metastatic tumors are the major differential diagnoses for the posterior fossa tumors in adults. Our purpose was to evaluate the efficacy of ASL in differentiating hemangioblastomas from metastatic brain tumors. METHODS: A total of 19 patients including 5 with a hemangioblastomas and 14 with metastatic tumors (7 from lung cancer, 4 from breast cancer, 1 from RCC, 1 from gastric cancer, and 1 from unknown origin) were enrolled in this study. ASL was performed using a pulsed ASL method at a 3-T unit. aTBF was measured as a mean absolute blood flow value within a region of interest drawn in the tumor. In addition, rTBF was obtained by normalizing the aTBF by a blood flow measured in the normal-appearing cortical gray matter. The aTBF and rTBF values were compared between hemangioblastomas and metastatic tumors using Student's t test. RESULTS: Both the aTBF and rTBF values were significantly higher in hemangioblastomas (mean aTBF ± SD = 437 ± 274 mL/100 g/min, mean rTBF ± SD = 7.96 ± 3.12) in comparison with metastatic brain tumors (mean aTBF ± SD = 125 ± 134 mL/100 g/min, mean rTBF ± SD = 2.98 ± 3.91; p < 0.05, respectively). However, a metastasis from RCC showed very high aTBF (559 mL/100 g/min) and rTBF (16.2). CONCLUSION: Our results demonstrated that ASL provides useful information to differentiate between hemangioblastomas and metastatic brain tumors. Metastasis from RCC may mimic hemangioblastoma on ASL blood flow measurement.

DOI： 10.1007/s00234-011-0977-5

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The purpose of this study was to determine the optimal computational options in voxel-based morphometry (VBM) for discrimination between Alzheimer's disease (AD) patients and healthy control (HC) subjects. Structural magnetic resonance images of 24 AD patients and 26 HC subjects were analyzed using VBM to determine brain regions with significant gray matter (GM) loss due to AD. The VBM analyses were performed with 4 different computational options: gray matter concentration (GMC) analysis with and without global normalization, and gray matter volume (GMV) analysis, with and without global normalization. Statistical maps calculated with the 4 computational options were obtained at 3 different P-value thresholds (P < 0.001, P < 0.0005, and P < 0.0001, uncorrected for multiple comparisons), yielding a total of 12 sets of maps, from which regions-of-interest (ROI) were generated for subsequent analyses of performance in terms of discrimination between AD patients and HC subjects as based on the mean value of either the GMC or GMV within the ROI for each of the 12 maps. Discrimination performance was evaluated by means of comparing the area-under-the-curve derived from the receiver-operating characteristic analysis as well as on the accuracy of the discrimination. Discrimination based on GMC analysis resulted in better performance than that based on GMV analysis. The best discrimination performance was achieved with GMC analysis either with or without proportional global normalization. The findings suggested that GMC-based VBM is better suited than GMV-based VBM for discrimination between AD patients and HC subjects.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: The purpose of this study was to determine the optimal computational options in voxel-based morphometry (VBM) for discrimination between Alzheimer's disease (AD) patients and healthy control (HC) subjects. MATERIALS AND METHODS: Structural magnetic resonance images of 24 AD patients and 26 HC subjects were analyzed using VBM to determine brain regions with significant gray matter (GM) loss due to AD. The VBM analyses were performed with 4 different computational options: gray matter concentration (GMC) analysis with and without global normalization, and gray matter volume (GMV) analysis, with and without global normalization. Statistical maps calculated with the 4 computational options were obtained at 3 different P-value thresholds (P < 0.001, P < 0.0005, and P < 0.0001, uncorrected for multiple comparisons), yielding a total of 12 sets of maps, from which regions-of-interest (ROI) were generated for subsequent analyses of performance in terms of discrimination between AD patients and HC subjects as based on the mean value of either the GMC or GMV within the ROI for each of the 12 maps. Discrimination performance was evaluated by means of comparing the area-under-the-curve derived from the receiver-operating characteristic analysis as well as on the accuracy of the discrimination. RESULTS: Discrimination based on GMC analysis resulted in better performance than that based on GMV analysis. The best discrimination performance was achieved with GMC analysis either with or without proportional global normalization. CONCLUSION: The findings suggested that GMC-based VBM is better suited than GMV-based VBM for discrimination between AD patients and HC subjects.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose We investigated the time interval from labeling to peak (TLP) of perfusion-signal intensity (SIs) in normal brain using a multiphase arterial spin-labeling (ASL) magnetic resonance imaging (MRI) technique as a fundamental study to assess the temporal characteristics of perfusion SIs. Materials and methods Twenty temporal phases of a pulsed ASL-MRI [QUASAR, quantitative signal targeting by alternating radiofrequency pulses (STAR) labeling of arterial regions] in single-slice imaging were performed in 9 volunteers. Perfusion SIs were measured and TLPs were calculated in 14 regions of interest (ROIs), 7 in each hemisphere: thalamus, lentiform nucleus, medial frontal cortex in the anterior cerebral artery (ACA) territory, temporal cortex in the middle cerebral artery (MCA) territory, medial occipital cortex in the posterior cerebral artery (PCA) territory, anterior watershed region (AWR) and posterior watershed region (PWR). Results Mean TLP varied with ROI (region and mean ± standard deviation in seconds): thalamus, 1.60 ± 0.11; lentiform nucleus, 1.52 ± 0.11; ACA territory, 1.53 ± 0.16; MCA territory, 1.59 ± 0.18; PCA territory, 1.68 ± 0.20; AWR, 1.79 ± 0.14; PWR, 2.00 ± 0.20. TLP in the PWR was significantly longer than those in all other regions except the AWR, and TLP in the AWR was significantly longer than those in the lentiform nucleus and the ACA territory. Conclusion Our results revealed regional differences in the temporal characteristics of perfusion SIs on ASL-MRI.

DOI： 10.1007/s11604-011-0025-8

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: We investigated the time interval from labeling to peak (TLP) of perfusion-signal intensity (SIs) in normal brain using a multiphase arterial spin-labeling (ASL) magnetic resonance imaging (MRI) technique as a fundamental study to assess the temporal characteristics of perfusion SIs. MATERIALS AND METHODS: Twenty temporal phases of a pulsed ASL-MRI [QUASAR, quantitative signal targeting by alternating radiofrequency pulses (STAR) labeling of arterial regions] in single-slice imaging were performed in 9 volunteers. Perfusion SIs were measured and TLPs were calculated in 14 regions of interest (ROIs), 7 in each hemisphere: thalamus, lentiform nucleus, medial frontal cortex in the anterior cerebral artery (ACA) territory, temporal cortex in the middle cerebral artery (MCA) territory, medial occipital cortex in the posterior cerebral artery (PCA) territory, anterior watershed region (AWR) and posterior watershed region (PWR). RESULTS: Mean TLP varied with ROI (region and mean ± standard deviation in seconds): thalamus, 1.60 ± 0.11; lentiform nucleus, 1.52 ± 0.11; ACA territory, 1.53 ± 0.16; MCA territory, 1.59 ± 0.18; PCA territory, 1.68 ± 0.20; AWR, 1.79 ± 0.14; PWR, 2.00 ± 0.20. TLP in the PWR was significantly longer than those in all other regions except the AWR, and TLP in the AWR was significantly longer than those in the lentiform nucleus and the ACA territory. CONCLUSION: Our results revealed regional differences in the temporal characteristics of perfusion SIs on ASL-MRI.

DOI： 10.1007/s11604-011-0025-8

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To test the feasibility of ultra-short echo time (UTE) MRI for assessment of regional pulmonary ventilation/perfusion in a standard 3 Tesla clinical MRI system. Materials and Methods: MRI of the lungs was conducted with an optimized three-dimensional UTE sequence in normal rats and in a rat model of pulmonary embolism (PE) induced by a blood clot. Changes in signal intensities (SIs) due to inhalation of molecular oxygen or intravenous (i.v.) injection of Gd, which represents the distribution of ventilation and perfusion, respectively, were assessed in the lung parenchyma. Results: The UTE MRI with a TE of 100 μs could detect and map the changes in SI of the lung parenchyma due to the inhalation of 100% oxygen or i.v. injection of Gd in normal rats. Reduced T1 resulting from oxygen inhalation was also quantified. These changes were not observed on the images that were obtained simultaneously with a conventional range of TE (2.3 ms). Furthermore, the method could delineate the embolized lesions where the lung ventilation and perfusion were mismatched in a rat model with PE. Conclusion: These results show the feasibility and diagnostic potential of UTE MRI for the assessment of pulmonary ventilation and perfusion which is essential for the evaluation of a variety of lung diseases.

DOI： 10.1002/jmri.22645

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To test the feasibility of ultra-short echo time (UTE) MRI for assessment of regional pulmonary ventilation/perfusion in a standard 3 Tesla clinical MRI system. MATERIALS AND METHODS: MRI of the lungs was conducted with an optimized three-dimensional UTE sequence in normal rats and in a rat model of pulmonary embolism (PE) induced by a blood clot. Changes in signal intensities (SIs) due to inhalation of molecular oxygen or intravenous (i.v.) injection of Gd, which represents the distribution of ventilation and perfusion, respectively, were assessed in the lung parenchyma. RESULTS: The UTE MRI with a TE of 100 μs could detect and map the changes in SI of the lung parenchyma due to the inhalation of 100&#37; oxygen or i.v. injection of Gd in normal rats. Reduced T1 resulting from oxygen inhalation was also quantified. These changes were not observed on the images that were obtained simultaneously with a conventional range of TE (2.3 ms). Furthermore, the method could delineate the embolized lesions where the lung ventilation and perfusion were mismatched in a rat model with PE. CONCLUSION: These results show the feasibility and diagnostic potential of UTE MRI for the assessment of pulmonary ventilation and perfusion which is essential for the evaluation of a variety of lung diseases.

DOI： 10.1002/jmri.22645

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The medial longitudinal fasciculus (MLF) is a white matter pathway in the brainstem that plays a key role in coordinating eye movements. Injury to the MLF leads to abnormalities in eye movements that can be measured with high precision by oculography, making it an ideal eloquent pathway to study imaging/function correlates. Tractography is an emerging method for identifying white matter pathways and offers the tantalizing promise of noninvasive, quantitative characterization of tissue integrity underlying functional deficits. However, the small caliber of the MLF and partial volume averaging with signal from nearby cerebrospinal fluid pose severe technical challenges to tractography-based delineation of the MLF. We discuss progress toward the goal of imaging the MLF and potential benefits of achieving this goal. Initial work suggests that ultra-high field (7 tesla) may complement tractography for characterizing the MLF.

DOI： 10.1111/j.1749-6632.2011.06156.x

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Nanoparticulate imaging probes have become an increasingly important arsenal in the visualization of molecular markers for early diagnosis and post-therapy assessment of diseases. Surface functionalization of these nanoparticles has led to the development of a variety of targeted nanoprobes for various imaging modalities (e.g. PET, MRI, optical). Despite these advances, detailed understanding of the nanoparticle targeting kinetics, particularly at the early time points immediately after injection, is still lacking. In this study, we report the combination of a T(2)*-weighted time-resolved-MRI (TR-MRI) method with ultra-sensitive superparamagnetic polymeric micelle (SPPM) nanoprobes to quantify the targeting kinetics of cyclic (RGDfK) (cRGD)-encoded SPPM to angiogenic endothelium in subcutaneous human tumor xenograft models in mice. TR-MRI analyses of the α(v)β(3)-targeted and non-targeted SPPMs allowed for the subtraction of blood volume and extravascular signal components from the cRGD-SPPM data, resulting in a specific measurement of the accumulation kinetics of nanoprobes in lung, breast and brain cancer preclinical models. In all three models, α(v)β(3)-specific accumulation of SPPM nanoprobes was observed in the first 5 mins after intravenous injection (first order rate constants were in the range of 0.22-0.24 min(-1)). Similar α(v)β(3)-targeting kinetics was observed for cRGD-SPPM nanoprobes in different tumor xenograft models, consistent with the targeting of mouse angiogenic endothelium despite tumor inoculation from different human cancer cell lines. Results from this study offer new opportunities in the quantitative characterization of the targeting kinetics of cancer-specific nanoparticles to their intended biological targets in an intact animal, which provides fundamental insights on molecular recognition processes in vivo for further development of these nanoprobes.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Fibrosis is a pathological process characterized by infiltration and proliferation of mesenchymal cells in interstitial space. A substantial portion of these cells is derived from residing non-epithelial and/or epithelial cells that have acquired the ability to migrate and proliferate. The mesenchymal transition is also observed in cancer cells to confer the ability to metastasize. Here, we show that renal fibrosis induced by unilateral ureteral obstruction and metastasis of human cancer xenografts are suppressed by administration of secreted Klotho protein to mice. Klotho is a single-pass transmembrane protein expressed in renal tubular epithelial cells. The extracellular domain of Klotho is secreted by ectodomain shedding. Secreted Klotho protein directly binds to the type-II TGF-β receptor and inhibits TGF-β1 binding to cell surface receptors, thereby inhibiting TGF-β1 signaling. Klotho suppresses TGF-β1-induced epithelial-to-mesenchymal transition (EMT) responses in cultured cells, including decreased epithelial marker expression, increased mesenchymal marker expression, and/or increased cell migration. In addition to TGF-β1 signaling, secreted Klotho has been shown to inhibit Wnt and IGF-1 signaling that can promote EMT. These results have raised the possibility that secreted Klotho may function as an endogenous anti-EMT factor by inhibiting multiple growth factor signaling pathways simultaneously.

DOI： 10.1074/jbc.M110.174037

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Off-resonance saturation (ORS) is a new magnetic resonance imaging (MRI) method that has shown greatly improved contrast sensitivity for the detection of cancer-specific biomarkers by superparamagnetic nanoprobes in vivo. However, quantitative understanding of the ORS contrast mechanism and its dependence on the structural parameters of superparamagnetic nanoprobes are still lacking. Here we propose a quantitative model of ORS contrast and its experimental validation by superparamagnetic polymeric micelles (SPPM) with precisely controlled structural properties. Size selected, monodisperse Fe₃O₄ nanoparticles (6.1 ± 0.2 nm) were used to form a series of SPPM nanoprobes with specifically controlled corona thickness using 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxypoly(ethylene glycol) (DSPE-PEG) with different PEG molecular weights. Transmission electron microscopy and dynamic light scattering showed that SPPM were uniform in size. The average hydrodynamic diameters of SPPM with PEG lengths of 0.55, 1, 2, and 5 kD were 16.6 ± 2.8, 18.4 ± 2.9, 24.1 ± 3.4, and 28.9 ± 3.4 nm, respectively. MRI experiments at 7 T determined that r₂ values of SPPM with 0.55, 1, 2, and 5 kD PEG as corona were 201 ± 3, 136 ± 8, 107 ± 5, and 108 ± 8 FemM⁻¹s⁻¹, respectively. ORS intensity from Z-spectra of SPPM showed a significant correlation with the inverse of T₂ relaxation rates (1/T₂, s⁻¹) of the SPPM nanoprobes regardless of the PEG corona thickness. These data provide the fundamental understanding of the structure-property relationships between the SPPM nanostructures and ORS sensitivity, which offers useful mechanistic insights for the future improvement of SPPM nanoprobes in cancer molecular imaging applications.

DOI： 10.1016/j.jmr.2010.12.013

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Fibrosis is a pathological process characterized by infiltration and proliferation of mesenchymal cells in interstitial space. A substantial portion of these cells is derived from residing non-epithelial and/or epithelial cells that have acquired the ability to migrate and proliferate. The mesenchymal transition is also observed in cancer cells to confer the ability to metastasize. Here, we show that renal fibrosis induced by unilateral ureteral obstruction and metastasis of human cancer xenografts are suppressed by administration of secreted Klotho protein to mice. Klotho is a single-pass transmembrane protein expressed in renal tubular epithelial cells. The extracellular domain of Klotho is secreted by ectodomain shedding. Secreted Klotho protein directly binds to the type-II TGF-β receptor and inhibits TGF-β1 binding to cell surface receptors, thereby inhibiting TGF-β1 signaling. Klotho suppresses TGF-β1-induced epithelial-to-mesenchymal transition (EMT) responses in cultured cells, including decreased epithelial marker expression, increased mesenchymal marker expression, and/or increased cell migration. In addition to TGF-β1 signaling, secreted Klotho has been shown to inhibit Wnt and IGF-1 signaling that can promote EMT. These results have raised the possibility that secreted Klotho may function as an endogenous anti-EMT factor by inhibiting multiple growth factor signaling pathways simultaneously.

DOI： 10.1074/jbc.M110.174037

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Off-resonance saturation (ORS) is a new magnetic resonance imaging (MRI) method that has shown greatly improved contrast sensitivity for the detection of cancer-specific biomarkers by superparamagnetic nanoprobes in vivo. However, quantitative understanding of the ORS contrast mechanism and its dependence on the structural parameters of superparamagnetic nanoprobes are still lacking. Here we propose a quantitative model of ORS contrast and its experimental validation by superparamagnetic polymeric micelles (SPPM) with precisely controlled structural properties. Size selected, monodisperse Fe ₃O₄ nanoparticles (6.1 ± 0.2 nm) were used to form a series of SPPM nanoprobes with specifically controlled corona thickness using 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxypoly(ethylene glycol) (DSPE-PEG) with different PEG molecular weights. Transmission electron microscopy and dynamic light scattering showed that SPPM were uniform in size. The average hydrodynamic diameters of SPPM with PEG lengths of 0.55, 1, 2, and 5 kD were 16.6 ± 2.8, 18.4 ± 2.9, 24.1 ± 3.4, and 28.9 ± 3.4 nm, respectively. MRI experiments at 7T determined that r ₂ values of SPPM with 0.55, 1, 2, and 5 kD PEG as corona were 201 ± 3, 136 ± 8, 107 ± 5, and 108 ± 8 Fe mM ^-1 s^-1, respectively. ORS intensity from Z-spectra of SPPM showed a significant correlation with the inverse of T₂ relaxation rates (1/T₂, s^-1) of the SPPM nanoprobes regardless of the PEG corona thickness. These data provide the fundamental understanding of the structure-property relationships between the SPPM nanostructures and ORS sensitivity, which offers useful mechanistic insights for the future improvement of SPPM nanoprobes in cancer molecular imaging applications.

DOI： 10.1016/j.jmr.2010.12.013

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The medial longitudinal fasciculus (MLF) is a white matter pathway in the brainstem that plays a key role in coordinating eye movements. Injury to the MLF leads to abnormalities in eye movements that can be measured with high precision by oculography, making it an ideal eloquent pathway to study imaging/function correlates. Tractography is an emerging method for identifying white matter pathways and offers the tantalizing promise of noninvasive, quantitative characterization of tissue integrity underlying functional deficits. However, the small caliber of the MLF and partial volume averaging with signal from nearby cerebrospinal fluid pose severe technical challenges to tractography-based delineation of the MLF. We discuss progress toward the goal of imaging the MLF and potential benefits of achieving this goal. Initial work suggests that ultra-high field (7 tesla) may complement tractography for characterizing the MLF.

DOI： 10.1111/j.1749-6632.2011.06156.x

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Previous functional neuroimaging studies found that the amygdala and other limbic regions may play a substantial role in social anxiety disorder (SAD). However, more widely distributed large-scale brain systems may be involved in cognitive processing in SAD patients when confronted with social situations. We employed functional MRI (fMRI) to investigate local brain activation of patients with SAD (n=6) and healthy controls (HC, n=9) during cognitive work. During fMRI scanning, subjects performed a social situation task using a block design paradigm in which the task and control trials were performed by turn. The patients with SAD showed higher anxiety levels during scanning in all social situations. The HC group showed greater common activation in the posterior cingulate cortex (PCC), cuneus, occipital gyrus, and cerebellum. Although the patients with SAD showed activation patterns similar to that of the HC group, they showed comparatively significant decreased activation in the left cerebellum, left precuneus, and bilateral PCC. The present study demonstrates that SAD may involve dysfunction of a broad neuronal network including the limbic system, parieto-posterior cortex and cerebellum. The findings contribute to previous findings that revealed abnormal activities of emotion-related regions including the amygdala and insular cortex during facial perception in SAD.

DOI： 10.1016/j.neures.2010.09.008

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: the purpose of this study was to examine interhemispheric asymmetry in volume of the caudate nucleus and its age dependency. METHODS: high-resolution T1-weighted brain magnetic resonance (MR) images were obtained for each subject using a 3-dimensional fast field-echo pulse sequence. The volumes of the bilateral caudate nuclei on MR images were measured using an automated method. Right-to-left comparison was made using paired t-test. Age-related change of right-to-left volume ratio (R/L ratio) was examined using Pearson's correlation coefficient. RESULTS: fifty healthy right-handed Japanese male subjects (age 12 to 67 years, mean 39.6 years) were involved in this study. The volume of right caudate nucleus was larger than the left in 48 of 50 subjects (P < .001). R/L ratio increased with age (r= .420, P < .01). CONCLUSIONS: our results confirmed the rightward volumetric asymmetry of caudate nucleus in right-handed individuals, and revealed that this asymmetry becomes notable with age.

DOI： 10.1111/j.1552-6569.2009.00403.x

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: The purpose of this study was to examine interhemispheric asymmetry in volume of the caudate nucleus and its age dependency. Methods: High-resolution T1-weighted brain magnetic resonance (MR) images were obtained for each subject using a 3-dimensional fast field-echo pulse sequence. The volumes of the bilateral caudate nuclei on MR images were measured using an automated method. Right-to-left comparison was made using paired t-test. Age-related change of right-to-left volume ratio (R/L ratio) was examined using Pearson's correlation coefficient. Results: Fifty healthy right-handed Japanese male subjects (age 12 to 67 years, mean 39.6 years) were involved in this study. The volume of right caudate nucleus was larger than the left in 48 of 50 subjects (P < .001). R/L ratio increased with age (r=420, P < 01). Conclusions: Our results confirmed the rightward volumetric asymmetry of caudate nucleus in right-handed individuals, and revealed that this asymmetry becomes notable with age.

DOI： 10.1111/j.1552-6569.2009.00403.x

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Previous functional neuroimaging studies found that the amygdala and other limbic regions may play a substantial role in social anxiety disorder (SAD). However, more widely distributed large-scale brain systems may be involved in cognitive processing in SAD patients when confronted with social situations. We employed functional MRI (fMRI) to investigate local brain activation of patients with SAD (n=6) and healthy controls (HC, n=9) during cognitive work. During fMRI scanning, subjects performed a social situation task using a block design paradigm in which the task and control trials were performed by turn. The patients with SAD showed higher anxiety levels during scanning in all social situations. The HC group showed greater common activation in the posterior cingulate cortex (PCC), cuneus, occipital gyrus, and cerebellum. Although the patients with SAD showed activation patterns similar to that of the HC group, they showed comparatively significant decreased activation in the left cerebellum, left precuneus, and bilateral PCC. The present study demonstrates that SAD may involve dysfunction of a broad neuronal network including the limbic system, parieto-posterior cortex and cerebellum. The findings contribute to previous findings that revealed abnormal activities of emotion-related regions including the amygdala and insular cortex during facial perception in SAD.

DOI： 10.1016/j.neures.2010.09.008

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Nonuniform disruption of lung architecture is usually assessed by CT, which carries potential radiation risk. Here we report our use of a three-dimensional ultrashort echo time MR method to image the lungs of normal mice at different positive end-expiratory pressures in a 3-T clinical MR system. The ultrashort echo time sequence in conjunction with a projection acquisition of the free induction decay could reduce the echo time to 100 μsec and provide a more inherent MR signal intensity from the lung parenchyma, which is usually invisible due to its short T₂ in conventional MRI methods. The signal intensity and T*₂ was reduced as the positive end-expiratory pressure became higher. Further, these parameters were highly correlated to the changes in lung volume (% lung expansion). The results indicated that the MR signal acquired at ultrashort echo time in the lung parenchyma represents interstitial tissue density including blood. The capability of acquiring sufficient MR signal would have implications for the direct assessment of parenchymal architecture in the lung. Therefore, ultrashort echo time imaging may have the potential to assist detection of early and localized pathological destruction of lung tissue architecture observed in various pulmonary disorders such as emphysema without incurring the risks of radiation exposure.

DOI： 10.1002/mrm.22521

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Nonuniform disruption of lung architecture is usually assessed by CT, which carries potential radiation risk. Here we report our use of a three-dimensional ultrashort echo time MR method to image the lungs of normal mice at different positive end-expiratory pressures in a 3-T clinical MR system. The ultrashort echo time sequence in conjunction with a projection acquisition of the free induction decay could reduce the echo time to 100 μsec and provide a more inherent MR signal intensity from the lung parenchyma, which is usually invisible due to its short T*(2) in conventional MRI methods. The signal intensity and T*(2) was reduced as the positive end-expiratory pressure became higher. Further, these parameters were highly correlated to the changes in lung volume (&#37; lung expansion). The results indicated that the MR signal acquired at ultrashort echo time in the lung parenchyma represents interstitial tissue density including blood. The capability of acquiring sufficient MR signal would have implications for the direct assessment of parenchymal architecture in the lung. Therefore, ultrashort echo time imaging may have the potential to assist detection of early and localized pathological destruction of lung tissue architecture observed in various pulmonary disorders such as emphysema without incurring the risks of radiation exposure.

DOI： 10.1002/mrm.22521

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Previous studies have demonstrated both functional and structural abnormalities in the frontal-striatal-thalamic circuits in obsessive-compulsive disorder (OCD). The purpose of this study was to assess volume abnormalities not only of gray matter (GM), but also of white matter (WM) in patients with OCD using voxel-based morphometry (VBM). Subjects consisted of 23 patients with OCD and 26 normal control subjects. All patients were drug-free for at least 2 weeks before the study. Three-dimensional T1-weighed MR images were obtained in all subjects. Optimized voxel-based morphometry was performed to detect structural difference between the two groups. The patients with OCD demonstrated a significant reduction of GM volume in the bilateral medial prefrontal cortex, right premotor area, right orbitofrontal cortex (OFC), right dorsolateral prefrontal cortex, and bilateral temporal and occipital regions. The OCD patients also showed a significant WM volume increase in the right anterior limb of the internal capsule, right orbitofrontal region, and a significant WM volume reduction in the left anterior cingulate gyrus. Our findings are consistent with previous studies implicating dysfunction of the frontal cortex including the OFC. The results suggested that WM volume abnormalities in the orbitofrontal region, anterior limb of the internal capsule, and anterior cingulate gyrus would imply abnormalities in the pathways of frontal-striatal circuits.

DOI： 10.1016/j.pscychresns.2010.06.011

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Previous studies have demonstrated both functional and structural abnormalities in the frontal-striatal-thalamic circuits in obsessive-compulsive disorder (OCD). The purpose of this study was to assess volume abnormalities not only of gray matter (GM), but also of white matter (WM) in patients with OCD using voxel-based morphometry (VBM). Subjects consisted of 23 patients with OCD and 26 normal control subjects. All patients were drug-free for at least 2 weeks before the study. Three-dimensional T1-weighed MR images were obtained in all subjects. Optimized voxel-based morphometry was performed to detect structural difference between the two groups. The patients with OCD demonstrated a significant reduction of GM volume in the bilateral medial prefrontal cortex, right premotor area, right orbitofrontal cortex (OFC), right dorsolateral prefrontal cortex, and bilateral temporal and occipital regions. The OCD patients also showed a significant WM volume increase in the right anterior limb of the internal capsule, right orbitofrontal region, and a significant WM volume reduction in the left anterior cingulate gyrus. Our findings are consistent with previous studies implicating dysfunction of the frontal cortex including the OFC. The results suggested that WM volume abnormalities in the orbitofrontal region, anterior limb of the internal capsule, and anterior cingulate gyrus would imply abnormalities in the pathways of frontal-striatal circuits.

DOI： 10.1016/j.pscychresns.2010.06.011

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Medulloblastoma is an aggressive childhood cerebellar tumor. We recently reported a mouse model with conditional deletion of Patched1 gene that recapitulates many characteristics of the human medulloblastoma. Qualitative symptoms observed in the mouse model include irregular stride length, impaired cranial nerve function and decreased motor coordination and performance. In our current study, several quantitative behavioral assays including a mouse rotarod, a forced air challenge, a screen inversion test, a horizontal wire test, and stride length analysis were evaluated to determine the most sensitive and cost-effective functional assay for impaired neuromotor behavior associated with disease progression. Magnetic resonance imaging (MRI) was used to confirm and monitor tumor growth and as an anatomical biomarker for therapeutic response. Wild type mice or medulloblastoma-prone, conditional Patched1 knockout mice were observed by behavioral assays and MRI from postnatal weeks 3-6. Bortezomib treatment was administered during this period and therapeutic response was assessed using cerebellar volumes at the end of treatment. Of the behavioral tests assessed in this study, stride length analysis was best able to detect differences between tumor-prone mice and wild type mice as early as postnatal day 37 (P=0.003). Significant differences between stride lengths of bortezomib treated and control tumor-bearing mice could be detected as early as postnatal day 42 (P=0.020). Cerebellar volumes measured by MRI at the end of treatment validated the therapeutic effects seen by behavioral tests (P=0.03). These findings suggest that stride length analysis may serve as one of the more sensitive and cost-effective method for assessing new therapeutic compounds in this and other preclinical model of brain tumors.

DOI： 10.1007/s11248-010-9361-1

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The objective of this study was to develop and evaluate an α_vβ₃-specific nanoprobe consisting of fluorescent superparamagnetic polymeric micelles (FSPPM) for in vivo imaging of tumor angiogenesis. Spherical micelles were produced using poly(ethylene glycol)-b-poly(D,L-lactide) co-polymers conjugated with tetramethylrhodamine, a fluorescent dye, and loaded with superparamagnetic iron oxide nanoparticles. The resulting micelle diameter was 50-70 nm by dynamic light scattering and transmission electron microscopy measurements. Micelles were encoded with an α_vβ₃-specific peptide, cyclic RGDfK, and optimized for maximum fluorescence and targeting in α_vβ ₃-overexpressing cells in vitro. In mice, cRGD-FSPPM-treated animals showed α_vβ₃-specific FSPPM accumulation in human lung cancer subcutaneous tumor xenografts. Together with the histological validation, the three-dimensional gradient echo magnetic resonance imaging (MRI) data provide high spatial resolution mapping and quantification of angiogenic vasculature in an animal tumor model using targeted, ultrasensitive MRI nanoprobes.

DOI： 10.1258/ebm.2010.010096

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To investigate the utility of ultra-short echo time (UTE) sequence as pulmonary MRI to detect non-uniform disruption of lung architecture that is typical of emphysema. MATERIALS AND METHODS: MRI of the lungs was conducted with a three-dimensional UTE sequence in transgenic mice with severe emphysema and their wild-type littermates in a 3 Tesla clinical MR system. Measurements of the signal intensity (SI) and transverse relaxation time (T2*) of the lung parenchyma were performed with various echo times (TEs) ranging from 100 micros to 2 ms. RESULTS: Much higher SI of the lung parenchyma was observed at an UTE of 100 micros compared with longer TEs. The emphysematous lungs had reduced SIs and T2* than the controls, in particular at end-expiratory phase. The results suggested that both SI and T2* in lung parenchyma measured with the method represent fractional volume of lung tissue. CONCLUSION: The UTE imaging provided MR signal from the lung parenchyma. Moreover, the UTE sequence was sensitive to emphysematous changes and may provide a direct assessment of lung parenchyma. UTE imaging has the potential to assist detection of localized pathological destruction of lung tissue architecture in emphysema.

DOI： 10.1002/jmri.22267

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The objective of this study was to develop and evaluate an alpha(v)beta(3)-specific nanoprobe consisting of fluorescent superparamagnetic polymeric micelles (FSPPM) for in vivo imaging of tumor angiogenesis. Spherical micelles were produced using poly(ethylene glycol)-b-poly(d,l-lactide) co-polymers conjugated with tetramethylrhodamine, a fluorescent dye, and loaded with superparamagnetic iron oxide nanoparticles. The resulting micelle diameter was 50-70 nm by dynamic light scattering and transmission electron microscopy measurements. Micelles were encoded with an alpha(v)beta(3)-specific peptide, cyclic RGDfK, and optimized for maximum fluorescence and targeting in alpha(v)beta(3)-overexpressing cells in vitro. In mice, cRGD-FSPPM-treated animals showed alpha(v)beta(3)-specific FSPPM accumulation in human lung cancer subcutaneous tumor xenografts. Together with the histological validation, the three-dimensional gradient echo magnetic resonance imaging (MRI) data provide high spatial resolution mapping and quantification of angiogenic vasculature in an animal tumor model using targeted, ultrasensitive MRI nanoprobes.

DOI： 10.1258/ebm.2010.010096

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To investigate the utility of ultra-short echo time (UTE) sequence as pulmonary MRI to detect non-uniform disruption of lung architecture that is typical of emphysema. Materials and Methods: MRI of the lungs was conducted with a three-dimensional UTE sequence in transgenic mice with severe emphysema and their wild-type litter-mates in a 3 Tesla clinical MR system. Measurements of the signal intensity (SI) and transverse relaxation time (T2*) of the lung parenchyma were performed with various echo times (TEs) ranging from 100 μs to 2 ms. Results: Much higher SI of the lung parenchyma was observed at an UTE of 100 μs compared with longer TEs. The emphysematous lungs had reduced SIs and T2* than the controls, in particular at end-expiratory phase. The results suggested that both SI and T2* in lung parenchyma measured with the method represent fractional volume of lung tissue. Conclusion: The UTE imaging provided MR signal from the lung parenchyma. Moreover, the UTE sequence was sensitive to emphysematous changes and may provide a direct assessment of lung parenchyma. UTE imaging has the potential to assist detection of localized pathological destruction of lung tissue architecture in emphysema.

DOI： 10.1002/jmri.22267

記述言語：英語   掲載種別：研究論文（学術雑誌）  

We report a rare case of giant cell glioblastoma that was difficult to distinguish from cerebral metastasis. The MRI finding was a ring-enhancing well-circumscribed solitary brain tumor that was very similar to cerebral metastasis. Even when MRI results were considered together with the findings by magnet resonance spectroscopy and perfusion-weighted MRI, it was hard to distinguish between giant cell glioblastoma and cerebral metastasis before surgery. When we find a solitary ring-enhancing intracranial mass with little tendency of invasion, we need to consider the possibility of giant cell GBM as a differential diagnosis.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

We report a rare case of giant cell glioblastoma that was difficult to distinguish from cerebral metastasis. The MRI finding was a ring-enhancing well-circumscribed solitary brain tumor that was very similar to cerebral metastasis. Even when MRI results were considered together with the findings by magnet resonance spectroscopy and perfusion-weighted MRI, it was hard to distinguish between giant cell glioblastoma and cerebral metastasis before surgery. When we find a solitary ring-enhancing intracranial mass with little tendency of invasion, we need to consider the possibility of giant cell GBM as a differential diagnosis.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To test, in a murine model of unilateral ureteral obstruction (UUO), whether the magnetic resonance (MR) imaging-derived apparent diffusion coefficient (ADC) changes during the progression of renal fibrosis and correlates with the histopathologic changes observed in renal fibrogenesis. Materials and Methods: This study was approved by the institutional animal care and use committee. A UUO was created in each of 14 mice. In five mice, longitudinal diffusion-weighted (DW) imaging was performed before the UUO (day 0) and on days 3 and 7 after the UUO and was followed by histopathologic analysis. The nine remaining mice were examined with cross-sectional studies on days 0 ( n = 4) and 3 ( n = 5). ADCs were measured with a spin-echo echo-planar sequence at five b values ranging from 350 to 1200 sec/mm². Differences in ADC among the time points and between the sides were assessed by using Tukey-Kramer and Student t tests, respectively. ADC was correlated with cell density and α-smooth muscle actin (α-SMA, a marker of myofibroblasts) expression at linear regression analysis. Results: Histopathologic examination revealed typical renal fibrosis on the side with UUO. The ADC decreased over time on the UUO side, from (1.02 ± 0.06 [standard deviation]) x 10^-3 mm²/sec on day 0 to (0.70 ± 0.08) x 10^-3 mm²/sec on day 3 (P < .001) and (0.57 ± 0.10) x 10^-3 mm²/sec on day 7 (P < .001). The percentage change in ADC was greater on the UUO side than on the contralateral side on days 3 (29% ± 9, P = .05) and 7 (44% ± 11, P < .01). ADC correlated with both increased cell density and increased α-SMA expression (P < .001 for both correlations). Conclusion: An ADC decrease in renal fibrosis is associated with an increased number of cells, including fibroblasts. ADC has the potential to serve as a sensitive noninvasive biomarker of renal fibrosis.

DOI： 10.1148/radiol.10091735

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To test, in a murine model of unilateral ureteral obstruction (UUO), whether the magnetic resonance (MR) imaging-derived apparent diffusion coefficient (ADC) changes during the progression of renal fibrosis and correlates with the histopathologic changes observed in renal fibrogenesis. MATERIALS AND METHODS: This study was approved by the institutional animal care and use committee. A UUO was created in each of 14 mice. In five mice, longitudinal diffusion-weighted (DW) imaging was performed before the UUO (day 0) and on days 3 and 7 after the UUO and was followed by histopathologic analysis. The nine remaining mice were examined with cross-sectional studies on days 0 (n = 4) and 3 (n = 5). ADCs were measured with a spin-echo echo-planar sequence at five b values ranging from 350 to 1200 sec/mm(2). Differences in ADC among the time points and between the sides were assessed by using Tukey-Kramer and Student t tests, respectively. ADC was correlated with cell density and alpha-smooth muscle actin (alpha-SMA, a marker of myofibroblasts) expression at linear regression analysis. RESULTS: Histopathologic examination revealed typical renal fibrosis on the side with UUO. The ADC decreased over time on the UUO side, from (1.02 +/- 0.06 [standard deviation]) x 10(-3) mm(2)/sec on day 0 to (0.70 +/- 0.08) x 10(-3) mm(2)/sec on day 3 (P < .001) and (0.57 +/- 0.10) x 10(-3) mm(2)/sec on day 7 (P < .001). The percentage change in ADC was greater on the UUO side than on the contralateral side on days 3 (29&#37; +/- 9, P = .05) and 7 (44&#37; +/- 11, P < .01). ADC correlated with both increased cell density and increased alpha-SMA expression (P < .001 for both correlations). CONCLUSION: An ADC decrease in renal fibrosis is associated with an increased number of cells, including fibroblasts. ADC has the potential to serve as a sensitive noninvasive biomarker of renal fibrosis.

DOI： 10.1148/radiol.10091735

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE. It is important to differentiate human herpesvirus 6 (HHV-6)-associated encephalopathy from herpes simplex encephalitis (HSE). Although these conditions are similar with regard to involvement of the mesial temporal lobe, HSE is sensitive to acyclovir but HHV-6 encephalopathy is not. We compared the imaging findings of the two conditions. MATERIALS AND METHODS. We encountered eight cases of HHV-6 encephalopathy and nine cases of HSE. We divided an observation time into early, middle, and late periods defined as 0-2, 3-30, and more than 30 days from the onset of neurologic symptoms. Differences between HHV-6 encephalopathy and HSE on CT scans in the early period and in distribution and temporal changes in the affected regions on MR images in the three periods were analyzed. RESULTS. At MRI in the early and middle periods, all eight patients with HHV-6 encephalopathy had exclusive involvement of the mesial temporal lobes, and all nine patients with HSE had involvement of both the mesial temporal lobes and the extratemporal regions (p < 0.01). Among patients who underwent head MRI, six of six with HHV-6 encephalopathy but none of six with HSE had resolution of high signal intensity on T2-weighted and FLAIR images (p < 0.01). Among patients who underwent head CT in the early period, none of the four with HHV-6 encephalopathy and six of the seven with HSE had abnormal findings, including parenchymal swelling, decreased attenuation of affected regions, and abnormal gyral enhancement (p < 0.05). CONCLUSION. Serial MRI showed transient abnormal signal intensity in the mesial temporal lobes in patients with HHV-6 encephalopathy but persistent abnormal signal intensity in both the mesial temporal lobes and the extratemporal regions in patients with HSE. CT in the early period showed no abnormality in patients with HHV-6 encephalopathy but definite abnormal findings in patients with HSE. These differences may be useful in the differential diagnosis of the two conditions.

DOI： 10.2214/AJR.09.2548

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Recent neuroimaging studies suggest that the pathophysiology of obsessive-compulsive disorder (OCD) may involve more widely distributed large-scale brain systems, including the parietal, occipital, and cerebellar areas, rather than the conventional orbitofronto-striatal model. We hypothesized that not only orbitofrontal cortex and caudate nucleus activities but also posterior brain regions might be associated with subsequent treatment response to serotonin reuptake inhibitors in OCD. The participants were 17 patients with OCD. Each patient was required to undergo fluvoxamine pharmacotherapy for 12 weeks. Before treatment, fMRI images of the subjects were obtained in the context of a symptom-provocation paradigm. The percentage changes in total Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) scores, from pre- to post-treatment, served as the index of treatment response. Statistical Parametric Mapping was used to identify brain loci where pre-treatment brain activation significantly correlated with the subsequent treatment response. Fifteen of 17 patients completed the 12-week treatment. During the symptom provocation task, patients showed brain activation in the left superior temporal gyrus (STG), left precuneus, left frontal cortices, right cerebellum, and right frontal cortices. We found that pre-treatment activation in the right cerebellum (Z-score=5.10, x,y,z=22,-84,-18) and the left STG (Z-score=4.95, x,y,z=-62,-22,0) was positively correlated with the improvement in the Y-BOCS score. Our results suggest that pre-treatment activation in the right cerebellum and in the left STG predict subsequent reduction in OCD symptom severity. There is every possibility that fMRI can be used as a tool to predict treatment response.

DOI： 10.1016/j.jpsychires.2009.08.007

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: It is important to differentiate human herpesvirus 6 (HHV-6)-associated encephalopathy from herpes simplex encephalitis (HSE). Although these conditions are similar with regard to involvement of the mesial temporal lobe, HSE is sensitive to acyclovir but HHV-6 encephalopathy is not. We compared the imaging findings of the two conditions. MATERIALS AND METHODS: We encountered eight cases of HHV-6 encephalopathy and nine cases of HSE. We divided an observation time into early, middle, and late periods defined as 0-2, 3-30, and more than 30 days from the onset of neurologic symptoms. Differences between HHV-6 encephalopathy and HSE on CT scans in the early period and in distribution and temporal changes in the affected regions on MR images in the three periods were analyzed. RESULTS: At MRI in the early and middle periods, all eight patients with HHV-6 encephalopathy had exclusive involvement of the mesial temporal lobes, and all nine patients with HSE had involvement of both the mesial temporal lobes and the extratemporal regions (p < 0.01). Among patients who underwent head MRI, six of six with HHV-6 encephalopathy but none of six with HSE had resolution of high signal intensity on T2-weighted and FLAIR images (p < 0.01). Among patients who underwent head CT in the early period, none of the four with HHV-6 encephalopathy and six of the seven with HSE had abnormal findings, including parenchymal swelling, decreased attenuation of affected regions, and abnormal gyral enhancement (p < 0.05). CONCLUSION: Serial MRI showed transient abnormal signal intensity in the mesial temporal lobes in patients with HHV-6 encephalopathy but persistent abnormal signal intensity in both the mesial temporal lobes and the extratemporal regions in patients with HSE. CT in the early period showed no abnormality in patients with HHV-6 encephalopathy but definite abnormal findings in patients with HSE. These differences may be useful in the differential diagnosis of the two conditions.

DOI： 10.2214/AJR.09.2548

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Recent neuroimaging studies suggest that the pathophysiology of obsessive-compulsive disorder (OCD) may involve more widely distributed large-scale brain systems, including the parietal, occipital, and cerebellar areas, rather than the conventional orbitofronto-striatal model. We hypothesized that not only orbitofrontal cortex and caudate nucleus activities but also posterior brain regions might be associated with subsequent treatment response to serotonin reuptake inhibitors in OCD. The participants were 17 patients with OCD. Each patient was required to undergo fluvoxamine pharmacotherapy for 12 weeks. Before treatment, fMRI images of the subjects were obtained in the context of a symptom-provocation paradigm. The percentage changes in total Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) scores, from pre- to post-treatment, served as the index of treatment response. Statistical Parametric Mapping was used to identify brain loci where pre-treatment brain activation significantly correlated with the subsequent treatment response. Fifteen of 17 patients completed the 12-week treatment. During the symptom provocation task, patients showed brain activation in the left superior temporal gyrus (STG), left precuneus, left frontal cortices, right cerebellum, and right frontal cortices. We found that pre-treatment activation in the right cerebellum (Z-score = 5.10, x, y, z = 22, - 84, - 18) and the left STG (Z-score = 4.95, x, y, z = - 62, - 22, 0) was positively correlated with the improvement in the Y-BOCS score. Our results suggest that pre-treatment activation in the right cerebellum and in the left STG predict subsequent reduction in OCD symptom severity. There is every possibility that fMRI can be used as a tool to predict treatment response.

DOI： 10.1016/j.jpsychires.2009.08.007

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Medulloblastoma is an aggressive childhood cerebellar tumor. We recently reported a mouse model with conditional deletion of Patched1 gene that recapitulates many characteristics of the human medulloblastoma. Qualitative symptoms observed in the mouse model include irregular stride length, impaired cranial nerve function and decreased motor coordination and performance. In our current study, several quantitative behavioral assays including a mouse rotarod, a forced air challenge, a screen inversion test, a horizontal wire test, and stride length analysis were evaluated to determine the most sensitive and cost-effective functional assay for impaired neuromotor behavior associated with disease progression. Magnetic resonance imaging (MRI) was used to confirm and monitor tumor growth and as an anatomical biomarker for therapeutic response. Wild type mice or medulloblastoma-prone, conditional Patched1 knockout mice were observed by behavioral assays and MRI from postnatal weeks 3-6. Bortezomib treatment was administered during this period and therapeutic response was assessed using cerebellar volumes at the end of treatment. Of the behavioral tests assessed in this study, stride length analysis was best able to detect differences between tumor-prone mice and wild type mice as early as postnatal day 37 (P = 0.003). Significant differences between stride lengths of bortezomib treated and control tumor-bearing mice could be detected as early as postnatal day 42 (P = 0.020). Cerebellar volumes measured by MRI at the end of treatment validated the therapeutic effects seen by behavioral tests (P = 0.03). These findings suggest that stride length analysis may serve as one of the more sensitive and cost-effective method for assessing new therapeutic compounds in this and other preclinical model of brain tumors.

DOI： 10.1007/s11248-010-9361-1

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Our purpose was to reveal potential regional variations in water molecular diffusivity within each cerebral hemisphere and across the right and left hemispheres. Diffusion-weighted images of 44 healthy right-handed adult male subjects were obtained using a diffusion tensor imaging sequence. Mean diffusivity (MD) values in subcortical white matter (WM) within 39 regions in each hemisphere were measured using an automated method. Intrahemispheric comparisons of MDs in subcortical WM were performed among six brain regions (frontal, parietal, occipital and temporal lobes and pre- and postcentral gyri). Interhemispheric comparisons of MDs were performed between the right and left counterparts of the 39 regions. In both hemispheres, diffusivity in the precentral gyrus was lower than those in other regions, while diffusivity in the parietal lobe was higher than others. MD asymmetry in which the left was lower than the right was found in the parietal lobe, middle occipital gyrus, and medial and orbital aspects of the frontal lobe. The converse asymmetry was revealed in the frontal operculum, supplementary motor cortex, temporal lobe, limbic cortices, precuneus and cuneus. Our results revealed significant intra- and interhemispheric regional variations in MD in subcortical WM, which may be related to different densities of axons and myelin sheaths.

DOI： 10.1007/s00330-009-1534-z

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Our purpose was to reveal potential regional variations in water molecular diffusivity within each cerebral hemisphere and across the right and left hemispheres. Diffusion-weighted images of 44 healthy right-handed adult male subjects were obtained using a diffusion tensor imaging sequence. Mean diffusivity (MD) values in subcortical white matter (WM) within 39 regions in each hemisphere were measured using an automated method. Intrahemispheric comparisons of MDs in subcortical WM were performed among six brain regions (frontal, parietal, occipital and temporal lobes and pre- and postcentral gyri). Interhemispheric comparisons of MDs were performed between the right and left counterparts of the 39 regions. In both hemispheres, diffusivity in the precentral gyrus was lower than those in other regions, while diffusivity in the parietal lobe was higher than others. MD asymmetry in which the left was lower than the right was found in the parietal lobe, middle occipital gyrus, and medial and orbital aspects of the frontal lobe. The converse asymmetry was revealed in the frontal operculum, supplementary motor cortex, temporal lobe, limbic cortices, precuneus and cuneus. Our results revealed significant intra- and interhemispheric regional variations in MD in subcortical WM, which may be related to different densities of axons and myelin sheaths.

DOI： 10.1007/s00330-009-1534-z

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The purpose of this study was to determine whether arterial spin labelling (ASL) at 3-T MR imaging can be used to discriminate individuals with Alzheimer's disease (AD) from cognitively normal subjects. Twenty AD patients and 23 cognitively normal control subjects were studied using ASL on a 3-T MR imager. Absolute regional cerebral blood flow (rCBF) maps were calculated. In addition, normalized rCBF maps were obtained using CBF in the sensorimotor cortex for normalization. A voxel-wise comparison of these rCBF maps between the AD and control groups was performed using the two-sample t test. Individuals with AD were discriminated from control subjects based on mean rCBF values within a region-of-interest defined by the t test, and the discriminating performance was evaluated by the receiver operating characteristic (ROC) analysis. Comparisons of both absolute and normalized rCBF maps revealed areas of significant hypoperfusion caused by the effects of AD in the bilateral precunei and posterior cingulate gyri. ROC analyses resulted in area under the curve (AUC) values of 0.861 to 0.877 for absolute and 0.910 to 0.932 for normalized rCBF. Our results suggest that ASL at 3-T MR imaging can be used to help discriminate individuals with AD from normal subjects.

DOI： 10.1007/s00330-009-1511-6

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The purpose of this study was to determine whether arterial spin labelling (ASL) at 3-T MR imaging can be used to discriminate individuals with Alzheimer's disease (AD) from cognitively normal subjects. Twenty AD patients and 23 cognitively normal control subjects were studied using ASL on a 3-T MR imager. Absolute regional cerebral blood flow (rCBF) maps were calculated. In addition, normalized rCBF maps were obtained using CBF in the sensorimotor cortex for normalization. A voxel-wise comparison of these rCBF maps between the AD and control groups was performed using the two-sample t test. Individuals with AD were discriminated from control subjects based on mean rCBF values within a region-of-interest defined by the t test, and the discriminating performance was evaluated by the receiver operating characteristic (ROC) analysis. Comparisons of both absolute and normalized rCBF maps revealed areas of significant hypoperfusion caused by the effects of AD in the bilateral precunei and posterior cingulate gyri. ROC analyses resulted in area under the curve (AUC) values of 0.861 to 0.877 for absolute and 0.910 to 0.932 for normalized rCBF. Our results suggest that ASL at 3-T MR imaging can be used to help discriminate individuals with AD from normal subjects.

DOI： 10.1007/s00330-009-1511-6

記述言語：英語   掲載種別：研究論文（学術雑誌）  

An off-resonance saturation (ORS) method was used for magnetic resonance imaging of superparamagnetic polymeric micelles (SPPM). SPPM was produced by encapsulating a cluster of magnetite nanoparticles (9.9+/-0.4 nm in diameter) in poly(ethylene glycol)-b-poly(D,L-lactide) (PEG-PLA) copolymer micelles (micelle diameter: 60+/-9 nm). In ORS MRI, a selective radiofrequency (RF) pulse was applied at an off-resonance position (0-50 ppm) from the bulk water signal, and the SPPM particles were visualized by the contrast on a division image constructed from two images acquired with and without pre-saturation. Here, the effects of saturation offset frequencies, saturation durations, and RF powers on ORS contrasts were investigated as these parameters are critical for optimization of ORS MRI for in vivo imaging applications. The ability to turn "ON" and "OFF" ORS contrast of SPPM solutions permits for an accurate image subtraction and a contrast enhancement to visualize SPPM probes for in vivo imaging of cancer.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Continuous maturation of cerebral white matter (WM) in the postadolescent period is not fully understood. To elucidate the time course and location of possible postadolescent maturational changes in cerebral WM, we studied 60 healthy male subjects who were in their second to seventh decade using diffusion-weighted imaging. Mean diffusivity (MD) in subcortical WM was measured in 78 cortical regions in each subject's brain using an automated method. Regression analysis was used to model the agerelated change in MD by either a linear or a quadratic function in each region. Age-related changes in subcortical MD were best modeled by either a linear function or a quadratic function in 27 regions including language-related regions, visual or multimodal areas in the bilateral occipital and temporal lobes, limbic areas including the bilateral parahippocampal gyri, and the bilateral postcentral and left precentral gyri. In these regions, the MD rapidly decreased until middle age and thereafter reached a plateau. Our results revealed microstructural changes in local subcortical WM and suggests a continuing maturational process in postoadolescent periods.

DOI： 10.1002/hbm.20738

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Continuous maturation of cerebral white matter (WM) in the postadolescent period is not fully understood. To elucidate the time course and location of possible postadolescent maturational changes in cerebral WM, we studied 60 healthy male subjects who were in their second to seventh decade using diffusion-weighted imaging. Mean diffusivity (MD) in subcortical WM was measured in 78 cortical regions in each subject's brain using an automated method. Regression analysis was used to model the age-related change in MD by either a linear or a quadratic function in each region. Age-related changes in subcortical MD were best modeled by either a linear function or a quadratic function in 27 regions including language-related regions, visual or multimodal areas in the bilateral occipital and temporal lobes, limbic areas including the bilateral parahippocampal gyri, and the bilateral postcentral and left precentral gyri. In these regions, the MD rapidly decreased until middle age and thereafter reached a plateau. Our results revealed microstructural changes in local subcortical WM and suggests a continuing maturational process in postoadolescent periods.

DOI： 10.1002/hbm.20738

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Background: The inconsistency of previous reports examining cognitive function in obsessive-compulsive disorder (OCD) suggests its heterogeneity. In this study, we examined the effect of illness duration on cognitive function in OCD. Methods: We examined the cognitive function of 32 OCD patients and 16 healthy volunteers by neuropsychological tests and functional magnetic resonance imaging while they performed the Stroop and N-back tasks to assess attention and nonverbal memory. The patients were divided into two groups by illness duration: a short-term group (n=17, 5.5±3.1 years) and a long-term group (n=15, 20.3±6.1 years). Statistical analysis was performed to determine the differences between these two groups and the normal control group (n=16). Results: The long-term group showed attention deficit and nonverbal memory dysfunction on the neuropsychological tests. In contrast, on functional magnetic resonance imaging, the short-term group showed weaker activation of the right caudate during the Stroop task and stronger activation of the right dorso-lateral prefrontal cortex during the N-back task than the long-term and normal control groups. Conclusions: The results suggested that abnormal brain activation occurs in the early phase of OCD and that the long-term persistence of OCD might involve a decline in cognitive function.

DOI： 10.1002/da.20484

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Modulation of water exchange in lanthanide(III)-DOTA type complexes has drawn considerable attention over the past two decades, particularly because of their application as contrast agents for magnetic resonance imaging. LnDOTA-tetraamide complexes display unusually slow water exchange kinetics and this chemical property offers an opportunity to use these complexes as a new type of contrast agent based upon the chemical exchange saturation transfer (CEST) mechanism. Six new DOTA-tetraamide ligands having side-chain amide arms with varying hydrophobicity and polarity were prepared and the water exchange characteristic of complexes formed with europium(III) complexes were investigated. The results show that introduction of steric bulk into the amide side-chain arms of the europium(III) complexes not only favors formation of the mono-capped twisted square antiprism coordination isomers, the isomer that is generally less favourable for CEST, but also accelerates water exchange in the mono-capped square antiprism isomers. However, converting single methyl groups on these bulky arms to carboxyl or carboxyl ethyl esters results in a rather dramatic decrease in water exchange rates, about 50-fold. Thus, steric bulk, polarity and hydrophobicity of the amide side-chains each contribute to organization of water molecules in the second hydration sphere of the europium(III) ion and this in turn controls water exchange in these complexes.

DOI： 10.1002/cmmi.279

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Previous neuropsychological studies indicate that OCD subtypes such as checking rituals might be associated with a working memory deficit. On the other hand, functional neuroimaging studies found functional abnormalities of the frontal cortex and subcortical structures in OCD. Combined with functional imaging method, we applied neuropsychological batteries to demonstrate a working memory deficit in OCD by comparison with normal controls. In addition, working memory and brain activation were further examined with symptom-based analysis. Forty patients with OCD and 25 normal controls were examined using neuropsychological tests including the WAIS-R, WCST, WMS-R, and R-OCFT and functional MRI (fMRI) during the N-back task including 0- and 2-back task. On fMRI, the brain regions activated during the performance and the differences in the activation between patients and controls were identified. Additional analyses of severity and subtypes were conducted by using Y-BOCS severity score, symptom-checklist and Leckman's four-factor model, respectively. On the neuropsychological tests, the OCD patients had significantly lower scores on the delayed recall section of the WMS-R and the immediate recall section of the R-OCFT compared to the controls. On fMRI, the patients showed greater activation in the right dorsolateral prefrontal cortex (DLPFC), left superior temporal gyrus (STG), left insula, and cuneus during two-back task compared to the controls. Right orbitofrontal cortex activity showed a significant positive correlation with Y-BOCS scores in OCD. Furthermore, patients with obsessions/checking rituals (n = 10) showed severer memory deficits and decreased activity in the postcentral gyrus than patients with cleanliness/washing rituals (n = 14). In conclusion, we found neuropsychological dysfunction and brain abnormalities in OCD. Furthermore, our results suggested that symptom severity and symptom subtype such as obsessions/checking might affect neuropsychological dysfunction and related brain activities.

DOI： 10.1016/j.jpsychires.2008.10.013

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Previous neuropsychological studies indicate that OCD subtypes such as checking rituals might be associated with a working memory deficit. On the other hand, functional neuroimaging studies found functional abnormalities of the frontal cortex and subcortical structures in OCD. Combined with functional imaging method, we applied neuropsychological batteries to demonstrate a working memory deficit in OCD by comparison with normal controls. In addition, working memory and brain activation were further examined with symptom-based analysis. Forty patients with OCD and 25 normal controls were examined using neuropsychological tests including the WAIS-R, WCST, WMS-R, and R-OCFT and functional MRI (fMRI) during the N-back task including 0- and 2-back task. On fMRI, the brain regions activated during the performance and the differences in the activation between patients and controls were identified. Additional analyses of severity and subtypes were conducted by using Y-BOCS severity score, symptom-checklist and Leckman's four-factor model, respectively. On the neuropsychological tests, the OCD patients had significantly lower scores on the delayed recall section of the WMS-R and the immediate recall section of the R-OCFT compared to the controls. On fMRI, the patients showed greater activation in the right dorsolateral prefrontal cortex (DLPFC), left superior temporal gyrus (STG), left insula, and cuneus during two-back task compared to the controls. Right orbitofrontal cortex activity showed a significant positive correlation with Y-BOCS scores in OCD. Furthermore, patients with obsessions/checking rituals (n=10) showed severer memory deficits and decreased activity in the postcentral gyrus than patients with cleanliness/washing rituals (n=14). In conclusion, we found neuropsychological dysfunction and brain abnormalities in OCD. Furthermore, our results suggested that symptom severity and symptom subtype such as obsessions/checking might affect neuropsychological dysfunction and related brain activities.

DOI： 10.1016/j.jpsychires.2008.10.013

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Background and Purpose: There are few comparative studies regarding morphologic changes after kyphoplasty and vertebroplasty. The purpose of this study was to compare restoration of vertebral body height and wedge angle and cement leakage with kyphoplasty and vertebroplasty in osteoporotic compression fractures. MATERIALS AND METHODS: Forty patients (57 vertebrae) were treated with kyphoplasty, and 66 patients (124 vertebrae) were treated with vertebroplasty. Cement leakage into the disk space and paravertebral soft tissues or veins was analyzed on immediate postoperative CT scans. The height and wedge angle were measured before and after treatment and analyzed with the Mann-Whitney U test and χ ² test. Results: Kyphoplasty and vertebroplasty both improved vertebral body height and the wedge angles (P < .05). However, these differences were not statistically significant when the 2 techniques were compared (P > .05). There were 18% of the kyphoplasty group and 49% of the vertebroplasty group that showed cement leakage into the paravertebral soft tissues or veins (P < .01). Cement leakage into the disk space occurred in 12% of the kyphoplasty group and in 25% of the vertebroplasty group (P < .01). However, no complications related to cement leakage were noted. Conclusions: Both kyphoplasty and vertebroplasty achieved the same degree of height restoration and improvement of the wedge angle. Kyphoplasty resulted in less cement leakage into the disk space and paravertebral soft tissues or veins than vertebroplasty.

DOI： 10.3174/ajnr.A1442

記述言語：英語   掲載種別：研究論文（その他学術会議資料等）  

An off-resonance saturation (ORS) method was used for magnetic resonance imaging of superparamagnetic polymeric micelles (SPPM). SPPM was produced by encapsulating a cluster of magnetite nanoparticles (9.9±0.4 nm in diameter) in poly(ethylene glycol)-b-poly(D,L-lactide) (PEGPLA) copolymer micelles (micelle diameter: 60±9 nm). In ORS MRI, a selective radiofrequency (RF) pulse was applied at an off-resonance position (0-50 ppm) from the bulk water signal, and the SPPM particles were visualized by the contrast on a division image constructed from two images acquired with and without pre-saturation. Here, the effects of saturation offset frequencies, saturation durations, and RF powers on ORS contrasts were investigated as these parameters are critical for optimization of ORS MRI for in vivo imaging applications. The ability to turn "ON" and "OFF" ORS contrast of SPPM solutions permits for an accurate image subtraction and a contrast enhancement to visualize SPPM probes for in vivo imaging of cancer.

DOI： 10.1109/IEMBS.2009.5334550

記述言語：英語   掲載種別：研究論文（学術雑誌）  

A 44-year-old man with a history of a foreign body in his right eye visited our hospital. On computed tomography a well-enhanced mass with low attenuation septal walls and a capsule was detected in the right orbit. On magnetic resonance imaging the mass showed inhomogenous high intensity on T2-weighted images and low intensity on diffusion-weighted images. The mass was histopathologically diagnosed as a lobular capillary hemangioma. This is the first report about image findings of lobular capillary hemangioma in the orbit.

DOI： 10.1007/s11604-008-0280-5

記述言語：英語   掲載種別：研究論文（学術雑誌）  

A 44-year-old man with a history of a foreign body in his right eye visited our hospital. On computed tomography a well-enhanced mass with low attenuation septal walls and a capsule was detected in the right orbit. On magnetic resonance imaging the mass showed inhomogenous high intensity on T2-weighted images and low intensity on diffusion-weighted images. The mass was histopathologically diagnosed as a lobular capillary hemangioma. This is the first report about image findings of lobular capillary hemangioma in the orbit.

DOI： 10.1007/s11604-008-0280-5

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Subsequent fracture after percutaneous vertebroplasty (PVP) has been reported. We experienced a case with immediate subsequent fractures proven by MR images. A 65-year-old female who had suffered from rheumatoid arthritis and had been treated with steroids for over 20 years had multiple compression fractures with severe kyphosis in the upper thoracic spine. The bone mineral density was extremely low (T-score = -6.1). Because of the presence of intraosseous clefts at T7 and T8, the patient received initial PVP for these fractures. Although the patient reported partial pain relief the day after the procedure, she complained of new back pain on the second day after the procedure. MR images obtained four days after the initial treatment revealed new compression fractures at T5 and T9. The patient received a second PVP without complications. The patient gained pain relief without medication and without the recurrence of fractures on MR imaging taken nine months after the second PVP. Steroid-induced severe osteoporosis, kyphosis and intraosseous clefts may be causal for these fractures. Repeat treatment can provide pain relief.

DOI： 10.1016/j.ejrex.2008.06.012

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: The usefulness of cone-beam C-arm CT for percutaneous vertebroplasty has not been fully evaluated. The purpose of this study was to assess the feasibility of cone-beam CT for evaluation before and after vertebroplasty. SUBJECTS AND METHODS: This prospective study included 22 consecutive patients (15 women and seven men) with osteoporotic compression fractures (51 vertebrae). Cone-beam CT and 64-MDCT were performed before and after percutaneous vertebroplasty. Multiplanar reformations of the axial, sagittal, and coronal planes were obtained. We evaluated the presence of cortical defects, vacuum phenomena in adjacent disks, and cement leakage, and we calculated the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of cone-beam CT compared with MDCT. RESULTS: All 75 cortical defects in 51 vertebrae seen on MDCT were also observed on cone-beam CT (100&#37; sensitivity and specificity). Vacuum phenomena were detected in 33 of 86 (38.4&#37;) adjacent disk spaces on MDCT and in 29 on cone-beam CT (84.8&#37; sensitivity, 98.1&#37; specificity, and 93.0&#37; accuracy). Cement leakage was noted at 17 disk spaces, 15 paravertebral soft tissues, and 12 veins on MDCT. All cement leakages were correctly identified on cone-beam CT. CONCLUSION: Cone-beam CT is able to correctly evaluate for vertebral fractures and vacuum phenomena in adjacent disks before vertebroplasty and for cement leakage after vertebroplasty.

DOI： 10.2214/AJR.08.1086

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE. The usefulness of cone-beam C-arm CT for percutaneous vertebroplasty has not been fully evaluated. The purpose of this study was to assess the feasibility of cone-beam CT for evaluation before and after vertebroplasty. SUBJECTS AND METHODS. This prospective study included 22 consecutive patients (15 women and seven men) with osteoporotic compression fractures (51 vertebrae). Cone-beam CT and 64-MDCT were performed before and after percutaneous vertebroplasty. Multiplanar reformations of the axial, sagittal, and coronal planes were obtained. We evaluated the presence of cortical defects, vacuum phenomena in adjacent disks, and cement leakage, and we calculated the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of cone-beam CT compared with MDCT. RESULTS. All 75 cortical defects in 51 vertebrae seen on MDCT were also observed on cone-beam CT (100% sensitivity and specificity). Vacuum phenomena were detected in 33 of 86 (38.4%) adjacent disk spaces on MDCT and in 29 on cone-beam CT (84.8% sensitivity, 98.1% specificity, and 93.0% accuracy). Cement leakage was noted at 17 disk spaces, 15 paravertebral soft tissues, and 12 veins on MDCT. All cement leakages were correctly identified on cone-beam CT. CONCLUSION. Cone-beam CT is able to correctly evaluate for vertebral fractures and vacuum phenomena in adjacent disks before vertebroplasty and for cement leakage after vertebroplasty.

DOI： 10.2214/AJR.08.1086

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Dysfunction of the frontal-subcortical circuits has been the most common finding in the pathophysiology of obsessive-compulsive disorder (OCD), and recent neuropsychological studies have shown cognitive impairments in OCD. To clarify the pathophysiology of OCD without the confounding effects of medication, we investigated the alterations of brain function in OCD patients and changes after clinical improvement due solely to behavior therapy. The participants were 11 outpatients with OCD and 19 normal controls. The patients received 12 weeks of behavior therapy. We investigated the differences in the behavioral performance and functional magnetic resonance imaging results during the Stroop test in the patients and normal controls, and their changes after treatment in the patients. The patients showed less activation in the anterior cingulate gyrus and cerebellum than control subjects. Following significant improvement in OC symptoms, the cerebellum and parietal lobe showed increased activation, and the orbitofrontal cortex, middle frontal gyrus, and temporal regions showed decreased activation during the Stroop task, and performance of the task itself improved. Our findings suggest that dysfunction of the posterior brain regions, especially the cerebellum, is involved in the pathogenesis of OCD, and that normalization in function can occur with improvement of OC symptoms.

DOI： 10.1016/j.pscychresns.2007.11.001

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: Glossopharyngeal neuralgia is rare but causes severe pain. We retrospectively evaluated preoperative MR images of patients with glossopharyngeal neuralgia caused by neurovascular compression. CONCLUSION: MRI may be beneficial in patients with glossopharyngeal neuralgia and an offending compressing artery. If the offending vessel was the posterior inferior cerebellar artery (PICA), a loop formation at the supraolivary fossette was always seen, whereas if it was the anterior inferior cerebellar artery (AICA), glossopharyngeal neuralgia was difficult to diagnose before surgery.

DOI： 10.2214/AJR.07.3025

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Dysfunction of the frontal-subcortical circuits has been the most common finding in the pathophysiology of obsessive-compulsive disorder (OCD), and recent neuropsychological studies have shown cognitive impairments in OCD. To clarify the pathophysiology of OCD without the confounding effects of medication, we investigated the alterations of brain function in OCD patients and changes after clinical improvement due solely to behavior therapy. The participants were 11 outpatients with OCD and 19 normal controls. The patients received 12 weeks of behavior therapy. We investigated the differences in the behavioral performance and functional magnetic resonance imaging results during the Stroop test in the patients and normal controls, and their changes after treatment in the patients. The patients showed less activation in the anterior cingulate gyrus and cerebellum than control subjects. Following significant improvement in OC symptoms, the cerebellum and parietal lobe showed increased activation, and the orbitofrontal cortex, middle frontal gyrus, and temporal regions showed decreased activation during the Stroop task, and performance of the task itself improved. Our findings suggest that dysfunction of the posterior brain regions, especially the cerebellum, is involved in the pathogenesis of OCD, and that normalization in function can occur with improvement of OC symptoms.

DOI： 10.1016/j.pscychresns.2007.11.001

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE. Glossopharyngeal neuralgia is rare but causes severe pain. We retrospectively evaluated preoperative MR images of patients with glossopharyngeal neuralgia caused by neurovascular compression. CONCLUSION. MRI may be beneficial in patients with glossopharyngeal neuralgia and an offending compressing artery. If the offending vessel was the posterior inferior cerebellar artery (PICA), a loop formation at the supraolivary fossette was always seen, whereas if it was the anterior inferior cerebellar artery (AICA), glossopharyngeal neuralgia was difficult to diagnose before surgery.

DOI： 10.2214/AJR.07.3025

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND AND PURPOSE: Previous studies have suggested that use of an artificial neural network (ANN) system is beneficial for radiological diagnosis. Our purposes in this study were to construct an ANN for the differential diagnosis of intra-axial cerebral tumors on MR images and to evaluate the effect of ANN outputs on radiologists' diagnostic performance. MATERIALS AND METHODS: We collected MR images of 126 patients with intra-axial cerebral tumors (58 high-grade gliomas, 37 low-grade gliomas, 19 metastatic tumors, and 12 malignant lymphomas). We constructed a single 3-layer feed-forward ANN with a Levenberg-Marquardt algorithm. The ANN was designed to differentiate among 4 categories of tumors (high-grade gliomas, low-grade gliomas, metastases, and malignant lymphomas) with use of 2 clinical parameters and 13 radiologic findings in MR images. Subjective ratings for the 13 radiologic findings were provided independently by 2 attending radiologists. All 126 cases were used for training and testing of the ANN based on a leave-one-out-by-case method. In the observer test, MR images were viewed by 9 radiologists, first without and then with ANN outputs. Each radiologist's performance was evaluated through a receiver operating characteristic (ROC) analysis on a continuous rating scale. RESULTS: The averaged area under the ROC curve for ANN alone was 0.949. The diagnostic performance of the 9 radiologists increased from 0.899 to 0.946 (P < .001) when they used ANN outputs. CONCLUSIONS: The ANN can provide useful output as a second opinion to improve radiologists' diagnostic performance in the differential diagnosis of intra-axial cerebral tumors seen on MR imaging.

DOI： 10.3174/ajnr.A1037

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To confirm the cortical thickness difference across the central sulcus (CS) visualized in the presence of vasogenic edema on MRI. Materials and methods: T2-weighted images of 70 cerebral hemispheres showing vasogenic edema infiltrating into subcortical white matter around the CS were studied retrospectively. Two neuroradiologists measured the cortical thickness of the anterior and posterior banks of the CS, precentral sulci (PrCS), and postcentral sulci (PoCS). Additionally, we compared the cortical thickness of the anterior and posterior banks of each sulcus visually using a grading scale. Results: On T2-weighted images, the cerebral cortex was highlighted by a high signal-intensity vasogenic edema in the adjacent white matter, and its thickness was readily measurable. The unique cortical thickness difference between the anterior and posterior banks of the CS were confirmed with measurements of 2.67 and 1.48 mm (p < 0.0001). The cortical measurements across other cerebral sulci were 2.04 and 1.95 mm (NS) for the PrCS, and 1.67 and 1.77 mm (NS) for the PoCS. The cortical thickness ratios were 1.86 for the CS, 1.05 for the PrCS, and 0.96 for the PoCS. On visual evaluation, the anterior bank of the CS was thicker than the posterior bank in 93% (65/70). For the PrCS and PoCS, the thickness of the anterior and posterior banks appeared to be equal in over 70% of the patients. Conclusion: A prominent cortical thickness difference across the CS in the presence of vasogenic edema was confirmed. This finding is considered to facilitate the identification of the CS in patients with brain tumors.

DOI： 10.1016/j.ejrad.2007.06.012

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To confirm the cortical thickness difference across the central sulcus (CS) visualized in the presence of vasogenic edema on MRI. MATERIALS AND METHODS: T2-weighted images of 70 cerebral hemispheres showing vasogenic edema infiltrating into subcortical white matter around the CS were studied retrospectively. Two neuroradiologists measured the cortical thickness of the anterior and posterior banks of the CS, precentral sulci (PrCS), and postcentral sulci (PoCS). Additionally, we compared the cortical thickness of the anterior and posterior banks of each sulcus visually using a grading scale. RESULTS: On T2-weighted images, the cerebral cortex was highlighted by a high signal-intensity vasogenic edema in the adjacent white matter, and its thickness was readily measurable. The unique cortical thickness difference between the anterior and posterior banks of the CS were confirmed with measurements of 2.67 and 1.48 mm (p<0.0001). The cortical measurements across other cerebral sulci were 2.04 and 1.95 mm (NS) for the PrCS, and 1.67 and 1.77 mm (NS) for the PoCS. The cortical thickness ratios were 1.86 for the CS, 1.05 for the PrCS, and 0.96 for the PoCS. On visual evaluation, the anterior bank of the CS was thicker than the posterior bank in 93&#37; (65/70). For the PrCS and PoCS, the thickness of the anterior and posterior banks appeared to be equal in over 70&#37; of the patients. CONCLUSION: A prominent cortical thickness difference across the CS in the presence of vasogenic edema was confirmed. This finding is considered to facilitate the identification of the CS in patients with brain tumors.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND AND PURPOSE: We investigated the relationship between tumor blood-flow measurement based on perfusion imaging by arterial spin-labeling (ASL-PI) and histopathologic findings in brain tumors. MATERIALS AND METHODS: We used ASL-PI to examine 35 patients with brain tumors, including 11 gliomas, 9 meningiomas, 9 schwannomas, 1 diffuse large B-cell lymphoma, 4 hemangioblastomas, and 1 metastatic brain tumor. As an index of tumor perfusion, the relative signal intensity (SI) of each tumor (%Signal intensity) was determined as a percentage of the maximal SI within the tumor per averaged SI within normal cerebral gray matter on ASL-PI. Relative vascular attenuation (%Vessel) was determined as the total microvessel area per the entire tissue area on CD-34-immunostained histopathologic specimens. MIB1 indices of gliomas were also calculated. The differences in %Signal intensity among different histopathologic types and between high- and low-grade gliomas were compared. In addition, the correlations between %Signal intensity and %Vessel or MIB1 index were evaluated in gliomas. RESULTS: Statistically significant differences in %Signal intensity were observed between hemangioblastomas versus gliomas (P < .005), meningiomas (P < .05), and schwannomas (P < .005). Among gliomas, %Signal intensity was significantly higher for high-grade than for low-grade tumors (P < .05). Correlation analyses revealed significant positive correlations between %Signal intensity and %Vessel in 35 patients, including all 6 histopathologic types (rs = 0.782, P < .00005) and in gliomas (rs = 0.773, P < .05). In addition, in gliomas, %Signal intensity and MIB1 index were significantly positively correlated (rs = 0.700, P < .05). CONCLUSION: ASL-PI may predict histopathologic vascular densities of brain tumors and may be useful in distinguishing between high- and low-grade gliomas and in differentiating hemangioblastomas from other brain tumors.

DOI： 10.3174/ajnr.A0903

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Rationale and Objectives: A method of estimating and mapping the cortical damage resulting from neurodegenerative diseases based on diffusion-weighted imaging was recently proposed. We improved on this method to visualize the cortical damage in Alzheimer's disease (AD) in the lateral and medial aspects of the cerebral hemispheres and to provide anatomic references. Materials and Methods: Damage in the cerebral cortex was estimated based on diffusivity in the subcortical white matter according to a previously published method. A map of subcortical mean diffusivity (MD) was superimposed on the corresponding anatomic image so that the spatial extent of the abnormality could be anatomically localized. The right and left hemispheres were separated to evaluate the medial and lateral aspects of each hemisphere. This method was applied to 10 healthy subjects and 11 AD patients. MDs within 20 cortical regions were visually evaluated and statistically compared between AD and healthy subjects at a significance level of P < .01. Results: In addition to the involvement of the lateral aspects of the bilateral parietal and temporal lobes and clear sparing of the bilateral pericentral regions that were previously reported, significant MD elevation was observed in the medial aspects of the right frontal, bilateral parietal, and right temporal lobes. The extent of MD abnormalities was easily identified by the background anatomic image. Conclusions: Results suggested that AD damage in the lateral and medial cerebral cortex can be visualized with an anatomic reference using our method.

DOI： 10.1016/j.acra.2007.10.008

記述言語：英語   掲載種別：研究論文（学術雑誌）  

RATIONALE AND OBJECTIVES: Conventional tractography based on the "streamline" method only partially visualizes the pyramidal tract because of fiber crossing with other white matter tracts. Recently a new tractography method based on directional diffusion function (DDF) has been proposed. This method was reported to visualize the pyramidal tract to a larger extent than conventional techniques do. To validate the DDF-based tractography method, we studied the somatotopic organization of the pyramidal tract in the posterior limb of the internal capsule (PLIC). MATERIALS AND METHODS: Pyramidal tracts in the intact hemispheres of 14 brain tumor patients were drawn using the directional diffusion function-based tractography method. Each pyramidal tract was divided into four fiber bundles according to the cephalocaudal positions of their termination in the precentral gyrus. The cephalocaudal positions in the precentral gyrus of the four fiber bundles were correlated with their positional relationships in the PLIC along the mediolateral and anteroposterior axes. RESULTS: Fiber bundles terminating more caudally in the precentral gyrus were located significantly more anteriorly in the PLIC (r = 0.59, Spearman's correlation coefficient, P < .0001). On the other hand, no significant correlation was shown between the cephalocaudal positions in the precentral gyrus of the four fiber bundles and their relative positions in the PLIC along the mediolateral axis. CONCLUSIONS: Estimated organization of the fiber bundles of the pyramidal tract in the PLIC was consistent with anatomically known somatotopic organization, which supported the validity of the DDF-based tractography method.

DOI： 10.1016/j.acra.2007.09.009

記述言語：英語   掲載種別：研究論文（学術雑誌）  

RATIONALE AND OBJECTIVES: A method of estimating and mapping the cortical damage resulting from neurodegenerative diseases based on diffusion-weighted imaging was recently proposed. We improved on this method to visualize the cortical damage in Alzheimer's disease (AD) in the lateral and medial aspects of the cerebral hemispheres and to provide anatomic references. MATERIALS AND METHODS: Damage in the cerebral cortex was estimated based on diffusivity in the subcortical white matter according to a previously published method. A map of subcortical mean diffusivity (MD) was superimposed on the corresponding anatomic image so that the spatial extent of the abnormality could be anatomically localized. The right and left hemispheres were separated to evaluate the medial and lateral aspects of each hemisphere. This method was applied to 10 healthy subjects and 11 AD patients. MDs within 20 cortical regions were visually evaluated and statistically compared between AD and healthy subjects at a significance level of P < .01. RESULTS: In addition to the involvement of the lateral aspects of the bilateral parietal and temporal lobes and clear sparing of the bilateral pericentral regions that were previously reported, significant MD elevation was observed in the medial aspects of the right frontal, bilateral parietal, and right temporal lobes. The extent of MD abnormalities was easily identified by the background anatomic image. CONCLUSIONS: Results suggested that AD damage in the lateral and medial cerebral cortex can be visualized with an anatomic reference using our method.

DOI： 10.1016/j.acra.2007.10.008

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Rationale and Objectives: Conventional tractography based on the "streamline" method only partially visualizes the pyramidal tract because of fiber crossing with other white matter tracts. Recently a new tractography method based on directional diffusion function (DDF) has been proposed. This method was reported to visualize the pyramidal tract to a larger extent than conventional techniques do. To validate the DDF-based tractography method, we studied the somatotopic organization of the pyramidal tract in the posterior limb of the internal capsule (PLIC). Materials and Methods: Pyramidal tracts in the intact hemispheres of 14 brain tumor patients were drawn using the directional diffusion function-based tractography method. Each pyramidal tract was divided into four fiber bundles according to the cephalocaudal positions of their termination in the precentral gyrus. The cephalocaudal positions in the precentral gyrus of the four fiber bundles were correlated with their positional relationships in the PLIC along the mediolateral and anteroposterior axes. Results: Fiber bundles terminating more caudally in the precentral gyrus were located significantly more anteriorly in the PLIC (r = 0.59, Spearman's correlation coefficient, P < .0001). On the other hand, no significant correlation was shown between the cephalocaudal positions in the precentral gyrus of the four fiber bundles and their relative positions in the PLIC along the mediolateral axis. Conclusions: Estimated organization of the fiber bundles of the pyramidal tract in the PLIC was consistent with anatomically known somatotopic organization, which supported the validity of the DDF-based tractography method.

DOI： 10.1016/j.acra.2007.09.009

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: Pulsed arterial spin labeling (PASL) is a magnetic resonance (MR) method for measuring cerebral blood flow. Although several validation studies for PASL in animals and humans have been reported, no reports have detailed the fundamental study of PASL using a flow phantom. We compared the true and theoretical flow rates in a flow phantom to confirm the analytical validity of quantitative perfusion imaging with Q2TIPS sequence. Methods: We built a flow phantom consisting of a 40-mm diameter plastic syringe filled with plastic beads and small plastic tubes 4 mm in diameter. Gd-DTPA-doped 8L water solution (0.1 mM) was circulated between the syringe and a tank through a plastic tube by a constant flow pump while the flow rate was adjusted between 0 and 2.61 cm/s. Q2TIPS sequence parameters were TI₁ = 50 ms and TI₂ = 1400 ms. Five imaging slices of 50 subtraction images were acquired sequentially in a distal-to-proximal direction using a single-shot echo planar imaging (EPI) technique. The theoretical flow rate calculated based upon the previously reported kinetic model for Q2TIPS was compared with the true flow rate. Results: A good linear relationship was observed between the theoretical, F', and true flow rates, F, in a flow rate range of 1.43 to 1.95 cm/s (F = 1.024-F- 1.915, R2 = 0.902). The ratio of theoretical to true flow rate was 92 (+/-) 4%. Conclusion: Flow rate was quantified with reasonable accuracy when the entire amount of labeled bolus within the phantom could be recovered. Our experiment confirmed the analytical validity of Q2TIPS and suggested that blood flow measurement may be feasible using the Q2TIPS pulse sequence and kinetic model of the PASL equation.

DOI： 10.2463/mrms.6.91

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Intraarterial therapy (IAT) for acute cerebral infarction has been proven to be profitable. However, the criteria for the indications, the choice of the thrombolytic agents, and the use of adjunctive agents are controversial. We retrospectively analyzed the prognostic factors of IAT. MATERIALS AND METHODS: From 1994 to 2003, 28 patients underwent IAT due to middle cerebral artery occlusion (17 women and 11 men; median age, 69 years old). We evaluated the following prognostic parameters: institution of treatment, degree of paralysis at visit, size of high-intensity area on diffusion-weighted images, dose of intraarterial urokinase administration, elapsed time from symptom onset to completion of IAT, presence of penetration of embolus by microcatheter and microguidewire, recanalization after IAT, intracranial hemorrhage (ICH) within 24 hours after IAT, and intravenous heparin administration after IAT. The outcome was evaluated at discharge and was classified into the following categories according to the modified Rankin Scale: independence (0 to 2), dependence (3 to 5), and death (6). RESULTS: Seven patients were judged to be independent, 16 patients were judged to be dependent, and five patients died. Patients with recanalization after IAT had a better outcome than those without (p < 0.05); patients with intracranial hemorrhage had a worse outcome than those without (p < 0.05); and patients with intravenous heparin administration after IAT had a better outcome in activities of daily living than those without (p < 0.05). CONCLUSION: In addition to ICH and recanalization, our results suggested that intravenous heparin administration after IAT had a favorable effect on patient outcome.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Intraarterial therapy (IAT) for acute cerebral infarction has been proven to be profitable. However, the criteria for the indications, the choice of the thrombolytic agents, and the use of adjunctive agents are controversial. We retrospectively analyzed the prognostic factors of IAT. MATERIALS AND METHODS: From 1994 to 2003, 28 patients underwent IAT due to middle cerebral artery occlusion (17 women and 11 men; median age, 69 years old). We evaluated the following prognostic parameters: institution of treatment, degree of paralysis at visit, size of high-intensity area on diffusion-weighted images, dose of intraarterial urokinase administration, elapsed time from symptom onset to completion of IAT, presence of penetration of embolus by microcatheter and microguidewire, recanalization after IAT, intracranial hemorrhage (ICH) within 24 hours after IAT, and intravenous heparin administration after IAT. The outcome was evaluated at discharge and was classified into the following categories according to the modified Rankin Scale: independence (0 to 2), dependence (3 to 5), and death (6). RESULTS: Seven patients were judged to be independent, 16 patients were judged to be dependent, and five patients died. Patients with recanalization after IAT had a better outcome than those without (p < 0.05); patients with intracranial hemorrhage had a worse outcome than those without (p < 0.05); and patients with intravenous heparin administration after IAT had a better outcome in activities of daily living than those without (p < 0.05). CONCLUSION: In addition to ICH and recanalization, our results suggested that intravenous heparin administration after IAT had a favorable effect on patient outcome.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Aging may alter the motor functions of the basal ganglia and cerebellum; however, no previous neuroimaging study has investigated the effect of aging on the functional connectivity of the motor loops involving these structures. Recently, using fMRI with a parametric approach and structural equation modeling (SEM), we demonstrated a significant functional interaction within the basal ganglia-thalamo-motor (BGTM) loop during self-initiated (SI) finger movement in young normal subjects, whereas cerebro-cerebellar (CC) loop was mainly involved during externally triggered (ET) movement. We applied this method to 12 normal aged subjects (53-72 years old) in order to study the effect of age on BGTM and CC loops. Compared with the functional connectivity seen in young subjects, SEM showed decreased connectivity in BGTM loops during SI task, decreased interaction in the CC loop during ET task, and increased connectivity within motor cortices and between hemispheres during both types of tasks. These results suggest an age-related decline of cortico-subcortical connectivity with increased interactions between motor cortices. Aging effects on SI and ET movements are probably caused by functional alterations within BGTM and CC loops.

DOI： 10.1016/j.neuroimage.2007.04.027

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Aging may alter the motor functions of the basal ganglia and cerebellum; however, no previous neuroimaging study has investigated the effect of aging on the functional connectivity of the motor loops involving these structures. Recently, using fMRI with a parametric approach and structural equation modeling (SEM), we demonstrated a significant functional interaction within the basal ganglia-thalamo-motor (BGTM) loop during self-initiated (SI) finger movement in young normal subjects, whereas cerebro-cerebellar (CC) loop was mainly involved during externally triggered (ET) movement. We applied this method to 12 normal aged subjects (53-72 years old) in order to study the effect of age on BGTM and CC loops. Compared with the functional connectivity seen in young subjects, SEM showed decreased connectivity in BGTM loops during SI task, decreased interaction in the CC loop during ET task, and increased connectivity within motor cortices and between hemispheres during both types of tasks. These results suggest an age-related decline of cortico-subcortical connectivity with increased interactions between motor cortices. Aging effects on SI and ET movements are probably caused by functional alterations within BGTM and CC loops.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

We present a case report in which a 4-year-old girl was involved in a fall that resulted in an injury of the right orbita. The girl kept a chopstick in her right hand that got into the right orbita due to this accident. Only a fraction remained in the orbita; the residual chopstick got lost. Hence, the substance of the chopstick was unknown. Computed tomography (CT) revealed a foreign body in the right orbita, but ophthalmologists had initially no indication of intervention. Further course according to the follow-up CT showed an increase of Hounsfield units (HU). These findings led to the assumption that the foreign body was made of wood. Through this, the ophthalmologists performed an evacuation. Motivated by these clinical results, we created an experimental setup that could demonstrate changes of HU in different coated chopsticks. It is concluded that wooden foreign bodies can display a variety of CT appearances depending on materials, types, coating, and time-course.

DOI： 10.1007/s10140-007-0597-x

記述言語：英語   掲載種別：研究論文（学術雑誌）  

We present a case report in which a 4-year-old girl was involved in a fall that resulted in an injury of the right orbita. The girl kept a chopstick in her right hand that got into the right orbita due to this accident. Only a fraction remained in the orbita; the residual chopstick got lost. Hence, the substance of the chopstick was unknown. Computed tomography (CT) revealed a foreign body in the right orbita, but ophthalmologists had initially no indication of intervention. Further course according to the follow-up CT showed an increase of Hounsfield units (HU). These findings led to the assumption that the foreign body was made of wood. Through this, the ophthalmologists performed an evacuation. Motivated by these clinical results, we created an experimental setup that could demonstrate changes of HU in different coated chopsticks. It is concluded that wooden foreign bodies can display a variety of CT appearances depending on materials, types, coating, and time-course.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Rationale and Objectives: White matter (WM) abnormality in Alzheimer's disease (AD) has been less well characterized than cortical damage. We studied the spatial distribution of the subcortical WM abnormality using diffusion-weighted magnetic resonance imaging (DWI). Materials and Methods: Twenty-one AD patients and seven healthy, elderly subjects were included. DWIs were obtained using a cerebrospinal fluid (CSF)-nulled pulse sequence to reduce the partial volume contamination of CSF signal. Diffusivity in the subcortical WM voxels was mapped onto the cortical surface using original software so that the spatial distribution of subcortical WM damage, which was visualized as an area of increased diffusivity, could be viewed in a three-dimensional map. The damages in the lateral surface of the bilateral cerebral hemispheres were visually evaluated, and severities of the damages in five brain regions were compared with each other. In addition, the severity of the damage in each region was correlated with patient's mini-mental state examination (MMSE) score. Results: In both hemispheres, clear sparing of the pericentral regions and predominant involvement of the parietal and temporal regions were revealed with statistical significance (P < .05, respectively). Marginal correlation (P < .05 uncorrected for multiple comparisons) was observed between the damage severity in the bilateral frontal and right temporal regions and patient's MMSE score. Conclusion: We demonstrated a subcortical WM abnormality over the parietal and temporal regions with clear sparing of the pericentral region using our mapping method, which supported the hypothesis that the subcortical WM abnormality in AD originates in Wallerian degeneration.

DOI： 10.1016/j.acra.2006.09.042

記述言語：英語   掲載種別：研究論文（学術雑誌）  

RATIONALE AND OBJECTIVES: White matter (WM) abnormality in Alzheimer's disease (AD) has been less well characterized than cortical damage. We studied the spatial distribution of the subcortical WM abnormality using diffusion-weighted magnetic resonance imaging (DWI). MATERIALS AND METHODS: Twenty-one AD patients and seven healthy, elderly subjects were included. DWIs were obtained using a cerebrospinal fluid (CSF)-nulled pulse sequence to reduce the partial volume contamination of CSF signal. Diffusivity in the subcortical WM voxels was mapped onto the cortical surface using original software so that the spatial distribution of subcortical WM damage, which was visualized as an area of increased diffusivity, could be viewed in a three-dimensional map. The damages in the lateral surface of the bilateral cerebral hemispheres were visually evaluated, and severities of the damages in five brain regions were compared with each other. In addition, the severity of the damage in each region was correlated with patient's mini-mental state examination (MMSE) score. RESULTS: In both hemispheres, clear sparing of the pericentral regions and predominant involvement of the parietal and temporal regions were revealed with statistical significance (P < .05, respectively). Marginal correlation (P < .05 uncorrected for multiple comparisons) was observed between the damage severity in the bilateral frontal and right temporal regions and patient's MMSE score. CONCLUSION: We demonstrated a subcortical WM abnormality over the parietal and temporal regions with clear sparing of the pericentral region using our mapping method, which supported the hypothesis that the subcortical WM abnormality in AD originates in Wallerian degeneration.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Rationale and Objective: Brain tissue damage in frontotemporal dementia (FTD) has never been systematically studied using diffusion-weighted imaging (DWI). We studied FTD patients using DWI to determine whether microstructural changes in white matter can be detected in vivo. Materials and Methods: Thirteen FTD patients and 15 aged healthy subjects were studied. Mean diffusivity (MD) abnormalities in 28 white matter regions were visually evaluated. In addition, MD values in 10 white matter regions relative to that in the ipsilateral postcentral gyrus were measured. The results were compared between healthy subjects and FTD patients. Results: The visual rating resulted in a significant MD elevation in FTD patients in the bilateral high superior frontal gyri, right orbitofrontal gyrus, bilateral anterior temporal lobes, and left middle temporal lobe (P < .01, respectively). Relative MD comparison revealed a significant MD elevation in FTD patients in the bilateral high superior frontal gyri, bilateral orbitofrontal gyri, and bilateral anterior temporal lobes (P < .05 after Bonferroni correction, respectively). Conclusion: Our results demonstrated white matter MD abnormalities in FTD patients. It was suggested that the observed white matter MD abnormalities are secondary to damage in the overlying cortex.

DOI： 10.1016/j.acra.2006.08.009

記述言語：英語   掲載種別：研究論文（学術雑誌）  

RATIONALE AND OBJECTIVE: Brain tissue damage in frontotemporal dementia (FTD) has never been systematically studied using diffusion-weighted imaging (DWI). We studied FTD patients using DWI to determine whether microstructural changes in white matter can be detected in vivo. MATERIALS AND METHODS: Thirteen FTD patients and 15 aged healthy subjects were studied. Mean diffusivity (MD) abnormalities in 28 white matter regions were visually evaluated. In addition, MD values in 10 white matter regions relative to that in the ipsilateral postcentral gyrus were measured. The results were compared between healthy subjects and FTD patients. RESULTS: The visual rating resulted in a significant MD elevation in FTD patients in the bilateral high superior frontal gyri, right orbitofrontal gyrus, bilateral anterior temporal lobes, and left middle temporal lobe (P < .01, respectively). Relative MD comparison revealed a significant MD elevation in FTD patients in the bilateral high superior frontal gyri, bilateral orbitofrontal gyri, and bilateral anterior temporal lobes (P < .05 after Bonferroni correction, respectively). CONCLUSION: Our results demonstrated white matter MD abnormalities in FTD patients. It was suggested that the observed white matter MD abnormalities are secondary to damage in the overlying cortex.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND AND PURPOSE: Human herpesvirus-6 (HHV-6)-associated encephalopathy tends to develop in immunocompromised patients. Neurologic symptoms, such as disorientation, short-term memory loss, convulsion, coma, and hypopnea could occur, but they may be nonspecific. We retrospectively reviewed MR images of 6 adults with HHV-6-associated encephalopathy to study characteristic imaging findings that could be useful in making the diagnosis. MATERIALS AND METHODS: Between 2003 and 2005, we encountered 6 cases of HHV-6-associated encephalopathy (3 men and 3 women; age range, 36-55 years) in 3 hospitals. The diagnosis was made clinically according to the neurologic symptoms accompanied by high-level copies of HHV-6 DNA in CSF or peripheral blood by quantitative polymerase chain reaction without the detection of any other infectious pathogen. RESULTS: All 6 patients had abnormal hippocampus/amygdala findings on presentation, and no other regions were involved. In the early period (0-2 days from onset), abnormal high signal intensity on fluid-attenuated inversion recovery (FLAIR) imaging (2 of 3, 67%) and on diffusion-weighted images accompanied by apparent diffusion coefficient (ADC) reduction (2 of 2, 100%) were observed. In the middle period (3-30 days), abnormal low signal intensity on T1-weighted images (5 of 6, 83%) and abnormal high signal intensity on T2-weighted images (4 of 6, 67%) and FLAIR (5 of 6, 83%) were confirmed. In the late period (> 30 days), we saw the resolution of signal intensity abnormalities and the appearance of atrophic change (4 of 4, 100%) of the affected regions. CONCLUSION: HHV-6-associated encephalopathy in adults tends to affect the mesial temporal lobe. MR imaging is useful for detecting HHV-6 encephalopathy and distinguishing it from the other diseases of the central nervous system in immunocompromised patients.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The basal ganglia and cerebellar loops are known to participate differently in self-initiated (SI) and externally triggered (ET) movements. However, no previous neuroimaging studies have illustrated functional organization of these loops in vivo. Here, we aimed to functionally visualize these loops during motor execution using functional magnetic resonance imaging (fMRI) with structural equation modeling (SEM). Twelve normal subjects (24-29 years old) were scanned while performing five different frequencies of sequential left finger movements using either SI or ET movements. Random effect analysis combined with a parametric approach revealed a significant positive linear dependence of cerebral activation upon movement rate in the right Put, GPi, VL, SMC and SMA during SI tasks. During ET tasks, significant positive linear relationships were found in the right SMC, VPL, left CB and DN, whereas tendency for linear relationships was seen in the right PMv. SEM further showed significant interactions within the right basal ganglia-thalamo-motor loop during SI tasks. In contrast, there were significant interactions within the entire right cerebral hemisphere-left cerebellar loop involving CB, DN, VPL, PMv and SMC during ET tasks. Therefore, our modeling approach enabled identification of different contributions of the motor loops of basal ganglia and cerebellum to SI and ET tasks during motor execution.

DOI： 10.1016/j.neuroimage.2005.12.032

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The basal ganglia and cerebellar loops are known to participate differently in self-initiated (SI) and externally triggered (ET) movements. However, no previous neuroimaging studies have illustrated functional organization of these loops in vivo. Here, we aimed to functionally visualize these loops during motor execution using functional magnetic resonance imaging (fMRI) with structural equation modeling (SEM). Twelve normal subjects (24-29 years old) were scanned while performing five different frequencies of sequential left finger movements using either SI or ET movements. Random effect analysis combined with a parametric approach revealed a significant positive linear dependence of cerebral activation upon movement rate in the right Put, GPi, VL, SMC and SMA during SI tasks. During ET tasks, significant positive linear relationships were found in the right SMC, VPL, left CB and DN, whereas tendency for linear relationships was seen in the right PMv. SEM further showed significant interactions within the right basal ganglia-thalamo-motor loop during SI tasks. In contrast, there were significant interactions within the entire right cerebral hemisphere-left cerebellar loop involving CB, DN, VPL, PMv and SMC during ET tasks. Therefore, our modeling approach enabled identification of different contributions of the motor loops of basal ganglia and cerebellum to SI and ET tasks during motor execution.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND AND PURPOSE: In Moyamoya disease, the relationship between cerebral hemodynamics and angiographic findings has not been fully evaluated. The purpose of this study is to evaluate hemodynamics in Moyamoya disease with perfusion-weighted MR imaging (PWI) and cerebral angiography. METHODS: Twenty patients with Moyamoya disease were the subjects. Mean transit time (MTT) derived from PWI was calculated in the medial frontal lobes, the posterior frontal lobes, the occipital lobes, and the basal ganglia. From the angiographies, we classified the degrees of internal carotid artery (ICA) and posterior cerebral artery (PCA) stenoses as well as the degrees of Moyamoya vessels and leptomeningeal anastomosis (LMA). MTT in each region was compared with the angiographic findings. RESULTS: MTT positively correlated with the degree of ICA stenosis in the medial frontal (P < .01), posterior frontal (P < .001), and occipital (P < .001) lobes, as well as in the basal ganglia (P < .001). MTT correlated with the degree of PCA stenosis in the medial frontal (P < .001), posterior frontal (P < .001), and occipital (P < .001) lobes, as well as in the basal ganglia (P < .001 ). MTT correlated with the degree of Moyamoya vessels in the medial frontal (P < .05) and posterior frontal (P < .01) lobes. A multivariate analysis revealed that ICA and PCA stenoses and Moyamoya vessels were independent factors that prolonged MTT. CONCLUSION: Both ICA and PCA stenoses may influence overall cerebral perfusion in Moyamoya disease. The development of Moyamoya vessels may indicate hemodynamic impairment.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: To reduce saline and heparin in continuous catheter perfusion in intraoperative cerebral angiography, a method using a syringe pump was tried. Materials and Methods: Ten patients with brain arteriovenous malformation (AVM) underwent intraoperative cerebral angiography. Seven internal carotid arteries (ICAs) and six vertebral arteries (VAs) were catheterized in these patients. Continuous catheter perfusion was performed at a low rate of 3 mL/hr with saline containing 8,000 units of heparin per liter using a syringe pump. Results: Mean duration of catheter perfusion was 8.3±4.0 hrs (range, 3.0 to 15.7 hrs). Mean volume of saline was 25.0±11.9 mL (range, 9 to 47 mL) per catheter. Mean dosage of heparin was 200.0±94.9 units (range, 72 to 376 units) per catheter. No complications due to intraoperative angiography were observed in this trial. Conclusion: Reduction of the saline volume and heparin dosage was possible in intraoperative cerebral angiography by the continuous perfusion of a small amount of high-concentration heparinized saline using a syringe pump.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: To reduce saline and heparin in continuous catheter perfusion in intraoperative cerebral angiography, a method using a syringe pump was tried. MATERIALS AND METHODS: Ten patients with brain arteriovenous malformation (AVM) underwent intraoperative cerebral angiography. Seven internal carotid arteries (ICAs) and six vertebral arteries (VAs) were catheterized in these patients. Continuous catheter perfusion was performed at a low rate of 3 mL/hr with saline containing 8,000 units of heparin per liter using a syringepump. RESULTS: Mean duration of catheter perfusion was 8.3 +/- 4.0 hrs (range, 3.0 to 15.7 hrs). Mean volume of saline was 25.0 +/- 11.9 mL (range, 9 to 47 mL) per catheter. Mean dosage of heparin was 200.0 +/- 94.9 units (range, 72 to 376 units) per catheter. No complications due to intraoperative angiography were observed in this trial. CONCLUSION: Reduction of the saline volume and heparin dosage was possible in intraoperative cerebral angiography by the continuous perfusion of a small amount of high-concentration heparinized saline using a syringe pump.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Previous studies have shown that diffusion-weighted imaging (DWI) is useful for detecting microstructural degradation of neuronal tissue in neurodegenerative diseases. Mapping of cortical degeneration by DWI is potentially useful, but is extremely difficult, mainly because of the partial volume effect resulting from the surrounding cerebrospinal fluid (CSF). In this study a novel method to map and display the cortical damage in neurodegenerative diseases using DWI is proposed. Instead of measuring the cortical diffusivity, the diffusivity of white matter directly beneath the cortex, where neuronal fibers enter or exit the overlying cortex, was measured and mapped onto the cortical surface. The map was viewed in a form of three-dimensional (3D) rendering. Patients with Alzheimer's disease (AD) showed cortical damage in the temporal and parietal cortices, and a patient with frontotemporal dementia showed damage in the frontal lobe, consistent with the typical topographical distribution of histopathological cortical damage in each of these diseases. The results suggest that subcortical diffusivity closely reflects cortical damage, and that the current mapping technique is a promising tool for evaluating neurodegenerative diseases.

DOI： 10.1002/mrm.20558

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Previous studies have shown that diffusion-weighted imaging (DWI) is useful for detecting microstructural degradation of neuronal tissue in neurodegenerative diseases. Mapping of cortical degeneration by DWI is potentially useful, but is extremely difficult, mainly because of the partial volume effect resulting from the surrounding cerebrospinal fluid (CSF). In this study a novel method to map and display the cortical damage in neurodegenerative diseases using DWI is proposed. Instead of measuring the cortical diffusivity, the diffusivity of white matter directly beneath the cortex, where neuronal fibers enter or exit the overlying cortex, was measured and mapped onto the cortical surface. The map was viewed in a form of three-dimensional (3D) rendering. Patients with Alzheimer's disease (AD) showed cortical damage in the temporal and parietal cortices, and a patient with frontotemporal dementia showed damage in the frontal lobe, consistent with the typical topographical distribution of histopathological cortical damage in each of these diseases. The results suggest that subcortical diffusivity closely reflects cortical damage, and that the current mapping technique is a promising tool for evaluating neurodegenerative diseases.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Background: Functional neuroimaging studies have implicated hyperactivity of the frontal cortex in obsessive-compulsive disorder (OCD); however, relationships between abnormal brain activity, clinical improvement, and neuropsychological function have not been clarified in OCD. To clarify the pathophysiology of this disorder, regional changes in brain function were examined during administration of cognitive and symptom provocation tasks in patients with OCD before and after treatment. Methods: Ten outpatients with OCD participated in the study. Functional magnetic resonance imaging (fMRI) was performed before and after treatment. Stroop and symptom provocation tasks were administered during fMRI. Each patient was randomly allocated to receive either pharmacotherapy with fluvoxamine 200 mg/day (n = 4) or behavior therapy (n = 6) for 12 weeks. Results: After 12-week treatment, mean (± SD) total score on the Yale-Brown Obsessive-Compulsive Scale decreased from 29.00 ± 3.59 to 14.60 ± 9.22, representing symptomatic improvement from moderate to mild. After symptom improvement, symptom provocation-related activation in the orbitofrontal, dorsolateral-prefrontal, and anterior cingulate cortices decreased. Conversely, Stroop task-related activation in the parietal cortex and cerebellum increased. Conclusions: After improvement of OCD with either fluvoxamine or behavioral therapy, hyperactivation of the frontal lobe related to a symptom-provocative state decreases, and posterior brain activity related to action-monitoring function increases.

DOI： 10.1016/j.biopsych.2004.12.039

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Percutaneous vertebroplasty is a radiologically guided therapeutic procedure that consists of percutaneous injection of polymethylmetacrylate (PMMA) into pathologic vertebral bodies. It is a minimally invasive procedure that is effective in the treatment of pain resulting from bone metastasis. This procedure has the advantage of providing rapid pain relief and spinal stabilization. A patient with severe, aggressive pain from metastatic lumbar spinal tumor of thyroid follicular carcinoma is presented herein. Despite treatment with analgesic agents, external beam radiation therapy, radioiodine therapy, and posterior fusion surgery, the pain reemerged and progressed. After percutaneous vertebroplasty, definite pain relief was achieved. Vertebroplasty would be useful as an additional or alternative pain relief method in patients with metastatic vertebral tumors.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Functional neuroimaging studies have implicated hyperactivity of the frontal cortex in obsessive-compulsive disorder (OCD); however, relationships between abnormal brain activity, clinical improvement, and neuropsychological function have not been clarified in OCD. To clarify the pathophysiology of this disorder, regional changes in brain function were examined during administration of cognitive and symptom provocation tasks in patients with OCD before and after treatment. METHODS: Ten outpatients with OCD participated in the study. Functional magnetic resonance imaging (fMRI) was performed before and after treatment. Stroop and symptom provocation tasks were administered during fMRI. Each patient was randomly allocated to receive either pharmacotherapy with fluvoxamine 200 mg/day (n = 4) or behavior therapy (n = 6) for 12 weeks. RESULTS: After 12-week treatment, mean (+/- SD) total score on the Yale-Brown Obsessive-Compulsive Scale decreased from 29.00 +/- 3.59 to 14.60 +/- 9.22, representing symptomatic improvement from moderate to mild. After symptom improvement, symptom provocation-related activation in the orbitofrontal, dorsolateral-prefrontal, and anterior cingulate cortices decreased. Conversely, Stroop task-related activation in the parietal cortex and cerebellum increased. CONCLUSIONS: After improvement of OCD with either fluvoxamine or behavioral therapy, hyperactivation of the frontal lobe related to a symptom-provocative state decreases, and posterior brain activity related to action-monitoring function increases.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Rationale and Objective. Structure of the brain is generally thought to remain stationary over the course of young adulthood. However, there is some evidence that microstructural changes of the brain do occur during this period. Magnetic resonance diffusion tensor imaging (DTI) provides quantitative measures of structural changes in the brain. We used DTI to detect possible age-related structural changes in the brains of young adults. Materials and Methods. Twenty-five healthy adults in their 20s and 30s were studied using DTI. Maps of mean diffusivity and fractional anisotropy (FA) were created for subsequent histogram and region-of-interest analyses, and the results were correlated with the respective ages of the subjects. Results. The histogram analysis revealed a significant increase in the mean FA value (r = 0.407, P <. 05) and a significant decrease in FA peak height (r = -0.578, P <. 002) with increasing age. No age-related changes were observed in indices derived from mean diffusivity maps. Region-of-interest analysis showed no focal white matter regions with significant FA change. Conclusion. Quantitative DTI revealed age-related structural changes in the brains of young adults. Changes on FA histograms observed in this study were considered to be related to changes in the relative volumes of gray and white matter and may represent maturational changes.

DOI： 10.1016/j.acra.2004.12.015

記述言語：英語   掲載種別：研究論文（学術雑誌）  

RATIONALE AND OBJECTIVE: Structure of the brain is generally thought to remain stationary over the course of young adulthood. However, there is some evidence that microstructural changes of the brain do occur during this period. Magnetic resonance diffusion tensor imaging (DTI) provides quantitative measures of structural changes in the brain. We used DTI to detect possible age-related structural changes in the brains of young adults. MATERIALS AND METHODS: Twenty-five healthy adults in their 20s and 30s were studied using DTI. Maps of mean diffusivity and fractional anisotropy (FA) were created for subsequent histogram and region-of-interest analyses, and the results were correlated with the respective ages of the subjects. RESULTS: The histogram analysis revealed a significant increase in the mean FA value (r = 0.407, P < .05) and a significant decrease in FA peak height (r = -0.578, P < .002) with increasing age. No age-related changes were observed in indices derived from mean diffusivity maps. Region-of-interest analysis showed no focal white matter regions with significant FA change. CONCLUSION: Quantitative DTI revealed age-related structural changes in the brains of young adults. Changes on FA histograms observed in this study were considered to be related to changes in the relative volumes of gray and white matter and may represent maturational changes.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Percutaneous vertebroplasty is a radiologically guided therapeutic procedure that consists of percutaneous injection of polymethylmetacrylate (PMMA) into pathologic vertebral bodies. It is a minimally invasive procedure that is effective in the treatment of pain resulting from bone metastasis. This procedure has the advantage of providing rapid pain relief and spinal stabilization. A patient with severe, aggressive pain from metastatic lumbar spinal tumor of thyroid follicular carcinoma is presented herein. Despite treatment with analgesic agents, external beam radiation therapy, radioiodine therapy, and posterior fusion surgery, the pain reemerged and progressed. After percutaneous vertebroplasty, definite pain relief was achieved. Vertebroplasty would be useful as an additional or alternative pain relief method in patients with metastatic vertebral tumors.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE. The purpose of this study was to determine the capability of dynamic contrast MRI to differentiate hemangioma from schwannoma of the orbit. MATERIALS AND METHODS. Sixteen patients (three males and 13 females; mean age, 39 ± 17.3 [SD] years; age range, 10-71 years) with unilateral orbital tumors, including eight cavernous hemangiomas and eight schwannomas, were examined. In addition to conventional MRI, we performed a dynamic contrast study (fast spin-echo sequence, 20-sec interval) after bolus administration of the contrast material (gadopentetate dimeglumine, 0.1 mmol/kg). We evaluated the features of the contrast enhancement spread pattern and the tumors' time-intensity curves. RESULTS. In the early phase, all the hemangiomas started the enhancement from one point or portion, although all the schwannomas started the enhancement from a wide area. The difference in the contrast-enhancement spread pattern features between the two types of tumors was statistically significant (p < 0.0001). The gradient of the time-intensity curve did not show a significant difference. CONCLUSION. Hemangioma and schwannoma of the orbit can be differentiated by the contrast-enhancement spread pattern on dynamic MRI.

DOI： 10.2214/ajr.183.6.01831799

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: The purpose of this study was to determine the capability of dynamic contrast MRI to differentiate hemangioma from schwannoma of the orbit. MATERIALS AND METHODS: Sixteen patients (three males and 13 females; mean age, 39 +/- 17.3 [SD] years; age range, 10-71 years) with unilateral orbital tumors, including eight cavernous hemangiomas and eight schwannomas, were examined. In addition to conventional MRI, we performed a dynamic contrast study (fast spin-echo sequence, 20-sec interval) after bolus administration of the contrast material (gadopentetate dimeglumine, 0.1 mmol/kg). We evaluated the features of the contrast enhancement spread pattern and the tumors' time-intensity curves. RESULTS: In the early phase, all the hemangiomas started the enhancement from one point or portion, although all the schwannomas started the enhancement from a wide area. The difference in the contrast-enhancement spread pattern features between the two types of tumors was statistically significant (p < 0.0001). The gradient of the time-intensity curve did not show a significant difference. CONCLUSION: Hemangioma and schwannoma of the orbit can be differentiated by the contrast-enhancement spread pattern on dynamic MRI.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE. The extracranial involvement of moyamoya disease has been reported in several studies. The main purpose of this study was to determine the prevalence of stenoocclusive lesions in the renal and major abdominal arteries in moyamoya disease. MATERIALS AND METHODS. Abdominal angiography was performed in 73 patients with idiopathic moyamoya disease. The findings of abdominal angiography were retrospectively reviewed for the presence and appearance of stenosis in the renal and other major abdominal arteries. RESULTS. Four (5%) of 73 patients presented with unilateral renal artery stenosis. Three patients had moderate stenosis, and one patient had mild stenosis. In the three patients with moderate stenosis, the renal artery stenosis was located in the proximal region of the main branch. Two patients (3%) with moderate stenosis of the unilateral renal artery had renovascular hypertension. No statistically significant differences were observed in age, sex, and the cerebral angiographic stage between patients with and without renal artery stenosis. No stenosis was found in the abdominal aorta or celiac, superior mesenteric, common hepatic, splenic, and proximal common iliac arteries. No occlusions were found in any abdominal arteries. CONCLUSION. The prevalence of renal artery stenosis in patients with moyamoya disease was 5% (4/73). Involvement of the proximal region of the renal artery was dominant. No stenosis was found in other abdominal arteries.

DOI： 10.2214/ajr.183.1.1830119

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: The extracranial involvement of moyamoya disease has been reported in several studies. The main purpose of this study was to determine the prevalence of stenoocclusive lesions in the renal and major abdominal arteries in moyamoya disease. MATERIALS AND METHODS: Abdominal angiography was performed in 73 patients with idiopathic moyamoya disease. The findings of abdominal angiography were retrospectively reviewed for the presence and appearance of stenosis in the renal and other major abdominal arteries. RESULTS: Four (5&#37;) of 73 patients presented with unilateral renal artery stenosis. Three patients had moderate stenosis, and one patient had mild stenosis. In the three patients with moderate stenosis, the renal artery stenosis was located in the proximal region of the main branch. Two patients (3&#37;) with moderate stenosis of the unilateral renal artery had renovascular hypertension. No statistically significant differences were observed in age, sex, and the cerebral angiographic stage between patients with and without renal artery stenosis. No stenosis was found in the abdominal aorta or celiac, superior mesenteric, common hepatic, splenic, and proximal common iliac arteries. No occlusions were found in any abdominal arteries. CONCLUSION: The prevalence of renal artery stenosis in patients with moyamoya disease was 5&#37; (4/73). Involvement of the proximal region of the renal artery was dominant. No stenosis was found in other abdominal arteries.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Formation of peripancreatic pseudoaneurysm is a well-known complication of the chronic pancreatitis. Wall of pseudoaneurysm is very fragile and prone to rupture, which can be fatal. Recently, transcatheter embolization of pseudoaneurysm has been used as the first line treatment with successful results. In most cases, embolization is performed early in the course, and temporal evolution is rarely documented. We report a case of pseudoaneurysm originating from the dorsal pancreatic artery, which developed secondary to chronic pancreatitis. The pseudoaneurysm rapidly enlarged in 8 days to 4cm. We successfully embolized the peudoaneurysm using micro-coil system.

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The effects of polaprezinc (an insoluble zinc complex of L-carnosine) on taste abnormalities were investigated in 22 patients receiving radiation therapy to head and neck malignancies. The total doses to the tongue were 25.5-46.0 Gy (mean, 37.9 Gy). All patients received 75 mg of polaprezinc two times a day with an interval of 0-1,561 days (mean, 305.3 days) after the completion of radiation therapy. The duration of the drug administration was 25-353 days (mean, 96.9 days). Twenty patients (90.9%) were aware of an improvement of a partial or complete loss of taste. Polaprezinc is effective in improving loss of taste after radiation therapy.

開催年月日： 2021年6月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福岡市   国名：日本国  

開催年月日： 2021年6月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：Web   国名：日本国  

開催年月日： 2021年3月

記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2020年6月 - 2020年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：Web   国名：日本国  

開催年月日： 2019年9月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：熊本市   国名：日本国  

開催年月日： 2018年11月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Beijing   国名：中華人民共和国  

開催年月日： 2018年8月 - 2018年9月

記述言語：日本語  

国名：日本国  

開催年月日： 2018年6月 - 2019年9月

記述言語：日本語  

開催地：金沢   国名：日本国  

開催年月日： 2018年3月

記述言語：日本語  

国名：大韓民国  

開催年月日： 2017年10月 - 2019年6月

記述言語：日本語  

開催地：Seoul   国名：大韓民国  

開催年月日： 2016年5月

記述言語：日本語   会議種別：口頭発表（招待・特別）  

国名：シンガポール共和国  

開催年月日： 2015年9月

記述言語：日本語   会議種別：口頭発表（招待・特別）  

国名：日本国  

開催地：Viena   国名：オーストリア共和国  

開催地：Tronto   国名：カナダ  

開催地：Honolulu   国名：アメリカ合衆国  

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開催地：横浜  

開催地：Melbuorne   国名：オーストラリア連邦  

会議種別：口頭発表（一般）  

開催地：Melbuorne   国名：オーストラリア連邦  

開催地：京都  

開催地：京都  

会議種別：口頭発表（一般）  

開催地：Paris   国名：フランス共和国  

開催地：Paris   国名：フランス共和国  

開催地：Chicago   国名：アメリカ合衆国  

開催地：Chicago   国名：アメリカ合衆国  

開催地：Saltlake City   国名：アメリカ合衆国  

開催地：Chicago   国名：アメリカ合衆国  

開催地：Milano   国名：イタリア共和国  

開催地：Milano   国名：イタリア共和国  

開催地：京都  

開催地：Chicago   国名：アメリカ合衆国  

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開催地：Tronto   国名：カナダ  

開催地：Tronto   国名：カナダ  

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開催地：東京  

開催地：Chicago   国名：アメリカ合衆国  

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開催地：Honolulu   国名：アメリカ合衆国  

開催地：Singapore  

開催地：Singapore   国名：シンガポール共和国  

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開催地：Chicago   国名：アメリカ合衆国  

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開催地：Honolulu   国名：アメリカ合衆国  

開催地：Honolulu   国名：アメリカ合衆国  

記述言語：英語  

開催地：宇都宮市   国名：日本国  

記述言語：日本語   掲載種別：記事・総説・解説・論説等（学術雑誌）  

記述言語：日本語   掲載種別：記事・総説・解説・論説等（学術雑誌）  

記述言語：日本語   掲載種別：記事・総説・解説・論説等（学術雑誌）  

記述言語：日本語   掲載種別：記事・総説・解説・論説等（学術雑誌）  

記述言語：日本語   掲載種別：記事・総説・解説・論説等（学術雑誌）