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DOI： 10.1038/s41598-024-68672-5

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Frontiers in Psychiatry  

BACKGROUND: Hoarding disorder (HD) is characterized by cognitive control impairments and abnormal brain activity in the insula and anterior cingulate cortex (ACC) during disposal of personal items or certain executive function tasks. However, whether there are any changes in resting-state functional connectivity of the insula and ACC remains unclear. METHODS: A total of 55 subjects, including 24 patients with HD and 31 healthy controls (HCs), participated in the study. We acquired resting-state functional magnetic resonance imaging data and examined group differences in functional connectivity from the insula and ACC in whole-brain voxels. RESULTS: In patients with HD, functional connectivity was significantly lower between the right insula and right inferior frontal gyrus (IFG) and left superior temporal gyrus (STG) compared to HCs. There was no correlation between these connectivities and HD symptoms. CONCLUSIONS: Although the clinical implication is uncertain, our results suggest that patients with HD have resting-state functional alterations between the insula and IFG and STG, corresponding with the results of previous fMRI studies. These findings provide new insight into the neurobiological basis of HD.

DOI： 10.3389/fpsyt.2024.1399062

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DOI： 10.1039/d3sc06957e

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Language：English   Publisher：(一社)日本神経学会  

Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Abstract

Magnetic resonance imaging of spinal dural arteriovenous fistula (SDAVF) shows longitudinally extensive spinal cord lesions mimicking neoplastic or inflammatory myelopathy. On positron emission tomography/computed tomography (PET/CT), we report two patients who showed focal ¹⁸F‐fluorodeoxyglucose (FDG) uptake in longitudinally extensive spinal cord lesions. These lesions were indistinguishable from tumors or myelitis but were finally diagnosed as SDAVF. Although PET/CT availability may be limited, in cases of myelopathy with diagnostic challenges, it is important to recognize that focal FDG uptake can be observed in SDAVF.

DOI： 10.1111/ncn3.12794

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Blood blister-like aneurysms (BBAs) are rare and challenging intracranial aneurysms. They pose significant diagnostic and surgical risks due to their delicate walls. Accounting for a small percentage of intracranial aneurysms, BBAs are pathologically pseudoaneurysms, often resulting from arterial dissection, with a high tendency to rupture. This report underscores the critical nature of BBAs by reviewing a case in which subarachnoid hemorrhage caused by a BBA rupture was difficult to diagnose with conventional imaging. We highlight the efficacy of three-dimensional (3D) high-resolution vessel wall imaging (VWI) in discerning the subtle vascular abnormality of BBAs. The integration of the black-blood imaging technique within VWI provides superior contrast between the aneurysm and surrounding tissues, facilitating clearer visualization of the aneurysmal wall. The use of 3D T1-weighted imaging provides intricate details of the vessel wall including its contrast enhancement, which is crucial for a comprehensive assessment of a ruptured aneurysm. This case is consistent with the existing literature, supporting the role of VWI in the identification of ruptured BBAs, an area with limited but growing information on its diagnostic value. VWI is precise and accurate in the preoperative diagnosis of BBAs, emphasizing its potential to improve patient management and outcomes, especially in conditions with high risks of morbidity and mortality.

DOI： 10.7759/cureus.58376

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Scientific Reports  

Moyamoya disease (MMD) is characterized by progressive arterial occlusion, causing chronic hemodynamic impairment, which can reduce brain volume. A novel quantitative technique, synthetic magnetic resonance imaging (SyMRI), can evaluate brain volume. This study aimed to investigate whether brain volume measured with SyMRI correlated with cerebral blood flow (CBF) and brain function in adult MMD. In this retrospective study, 18 adult patients with MMD were included. CBF was measured using iodine-123-N-isopropyl-p-iodoamphetamine single photon emission computed tomography. Cerebrovascular reactivity (CVR) to acetazolamide challenge was also evaluated. Brain function was measured using the Wechsler Adult Intelligence Scales (WAIS)-III/IV and the WAIS-R tests. Gray matter (GM), white matter, and myelin-correlated volumes were evaluated in six areas. Resting CBF was positively correlated with GM fractions in the right anterior cerebral arterial and right middle cerebral arterial (MCA) territories. CVR was positively correlated with GM fraction in the right posterior cerebral arterial (PCA) territory. Full-Scale Intelligence Quotient and Verbal Comprehension Index scores were marginally positively correlated with GM fractions in the left PCA territory. Processing Speed Index score was marginally positively correlated with GM fraction in the right MCA territory. The SyMRI-measured territorial GM fraction correlated with CBF and brain function in patients with MMD.

DOI： 10.1038/s41598-024-56210-2

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DOI： 10.1016/j.bios.2023.115862

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Neuroradiology  

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

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DOI： 10.1016/j.pediatrneurol.2023.12.011

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Publisher：学研メディカル秀潤社  

DOI： 10.15105/gz.0000005316

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Language：Japanese   Publisher：(公社)日本医学放射線学会  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Neuroradiology  

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%; p < 0.001) than on DSC (5/32, 15.6%). 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

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本稿では,ASLの原理と臨床応用について概説する.ASLは,動脈血を内因性トレーサーとして使用して脳灌流を画像化する非侵襲的手法であり,脳虚血,脳腫瘍,急性脳炎,脳症など様々な疾患の診断に有用である.また,脳血流量などの脳循環指標の定量化を行うことも可能である他,MRA技術として用いることもできる.

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本稿では,ASLの原理と臨床応用について概説する.ASLは,動脈血を内因性トレーサーとして使用して脳灌流を画像化する非侵襲的手法であり,脳虚血,脳腫瘍,急性脳炎,脳症など様々な疾患の診断に有用である.また,脳血流量などの脳循環指標の定量化を行うことも可能である他,MRA技術として用いることもできる.

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Other Link： https://search.jamas.or.jp/default/link?pub_year=2024&ichushi_jid=J00235&link_issn=&doc_id=20240301020020&doc_link_id=10.15105%2FGZ.0000005316&url=https%3A%2F%2Fdoi.org%2F10.15105%2FGZ.0000005316&type=%E5%8C%BB%E6%9B%B8.jp_%E3%82%AA%E3%83%BC%E3%83%AB%E3%82%A2%E3%82%AF%E3%82%BB%E3%82%B9&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00024_2.gif

Language：Japanese   Publisher：(公社)日本医学放射線学会  

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DOI： 10.1039/d3sc04953a

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DOI： 10.3233/SHTI230977

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Neuroradiology Journal  

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

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DOI： 10.1111/mec.17216

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Language：Japanese   Publisher：(株)日本臨床社  

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Language：Japanese   Publisher：(株)インナービジョン  

2021年に,WHO中枢神経系腫瘍分類第5版が出版された。最大の特徴として,組織学的所見と比べた分子遺伝学的情報の診断への寄与度が,2016年出版の改訂第4版以上に顕著となっており,腫瘍型分類にも反映されている。これは,主に分子遺伝学的所見による分類が,生命予後や治療反応性と相関することがエビデンスとして示されたことによる。画像診断学は病理組織所見との対比により発展してきたが,今回の腫瘍型分類改訂に伴い,従来の方法では術前の腫瘍型推定が困難な症例にも直面している。それでも,WHO中枢神経系腫瘍分類第5版では,発生部位,組織学的グレーディングおよび分子遺伝学的所見の組み合わせによる統合診断・層別化が重視されており,信号パターン以外にも,局在や広がりが非侵襲的に評価できる画像情報が術前診断に果たす役割は大きい。本稿では,腫瘍の縦緩和時間(T1値),横緩和時間(T2値),プロトン密度(PD)を同時取得する手法として,synthetic MRIの二次元Quantification of Relaxation Times and Proton Density by Multi-Echo acquisition of a saturation-recovery using Turbo spin-Echo Read-out(2D-QRAPMASTER)および3D-quantification using an interleaved Look-Locker acquisition sequence with a T2 preparation pulse(3D-QALAS)法について概説し,pseudo-3D DWI using echo planar imaging with compressed SENSE(EPICS-DWI)を用いたapparent diffusion coefficient(ADC)定量法,最後に,MR spectroscopy(MRS)を用いた分子遺伝学的所見検出の可能性について紹介する。(著者抄録)

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：European Journal of Radiology Open  

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

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DOI： 10.1038/s42004-023-01054-6

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Journal of Magnetic Resonance Imaging  

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

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Language：English   Publisher：Neuroradiology  

The original article contains an error during online publication. There was an error in the previous version of Table 2. Specifically, the values of rrTBF for IDHm-noncodel and IDHm-codel were identical at 1.24 ± 1.23 [0.76–1.71]. The authors have provided a corrected version below. (Table presented.) Differences between IDHw, IDHm-noncodel and IDHm-codel in the ASL parameters IDHw (n = 21) IDHm-noncodel (n = 28) IDHm-codel (n = 22) P-value ASL Cortical high-flow sign 2/21(9.5%) 2/28(7.1%) 12/22(54.5%) <0.0001* rrTBF 1.31 ± 0.56 [1.05–1.56] 1.24 ± 1.23 [0.76–1.71] 1.31 ± 0.60 [1.05–1.58] 0.9473 *p < 0.05

DOI： 10.1007/s00234-023-03228-4

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Language：English   Publisher：Journal of Physiological Anthropology  

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

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Neuroradiology  

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

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Language：English   Publisher：(一社)日本生理人類学会  

失感情症と脳機能の関係について安静時に取得した動脈スピンラベリング(ASL)データの解析による検討を行った。健常成人42人(男性14人、女性28人、平均31.2±9.5歳)を対象として、ASLと20-item Toronto Alexithymia Scale(TAS-20)アンケート調査を用いて脳の構造及び機能イメージング研究を行った。ASLデータから、デフォルトモードネットワーク、salience network及びセントラルエグゼクティブネットワークにおける関心領域に対する脳血流及び機能的結合の値を算出した。機能的結合分析により、右島皮質及び左前帯状皮質の機能的結合と、TAS-20のトータルスコア、感情を特定することの困難さ、感情を語ることの困難さのサブスコアに負の相関がみられた。これらのスコアが高いほどこれらの領域間の機能的結合は弱くなった。この相関は偏相関分析を用いて不安及び抑鬱を調整した後でも有意であった。

Publisher：学研メディカル秀潤社  

DOI： 10.15105/gz.0000004785

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Publisher：学研メディカル秀潤社  

DOI： 10.15105/gz.0000004788

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Neuroradiology  

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

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Language：English   Publisher：(一社)日本脳神経外科学会  

膠芽腫患者を対象とした後ろ向き研究を実施し、FLAIR病変切除率を評価することで、supramaximal resection(SMR)の臨床効果について検討した。2006年12月～2018年8月に神経膠腫と診断された成人患者のうち、肉眼的全切除(GTR)が施行された成人33例(年齢中央値64歳、男性19例)を対象とした。評価項目は腫瘍切除率(手術前後のFLAIRおよびガドリニウム強調T1強調画像の腫瘍体積を3D画像体積分析装置により測定)、SMR率(0%から10%刻み)などとした。腫瘍を皮質灰白質との接触により、皮質群23例(SMR 8例、GTR 15例)、深在性群10例(SMR 4例、全切除6例)に分けて検討した。その結果、SMR閾値が30%以上の場合に全生存期間の改善が観察された。皮質群ではGTRと比較してSMRで全生存期間が延長する傾向が認められた(69.6ヵ月対22.1ヵ月)。一方、深在群ではGTRと比較してSMRで全生存期間が有意に短縮していた(10.2ヵ月対27.9ヵ月、p=0.0221)。以上から、FLAIR病変のsupramaximal resectionは神経膠腫患者の生存期間を延長可能であることが示された。

Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Japan Neurosurgical Society  

<p>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% increments from 0% and compared their overall survival (OS) change. An improvement in OS was observed when the threshold value of SMR was 30% 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% or more volume reduction is achieved in FLAIR lesions, although the impact of SMR for deep-seated GBM must be validated in larger cohorts.</p>

DOI： 10.2176/jns-nmc.2022-0351

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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

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DOI： 10.1038/s43856-023-00314-9

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DOI： 10.3389/fpubh.2023.1224093

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DOI： 10.1039/d3sc00724c

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DOI： 10.1021/acs.analchem.3c00163

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DOI： 10.1186/s12916-023-02862-2

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Language：Japanese   Publisher：(公社)日本医学放射線学会  

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Language：Japanese   Publisher：(公社)日本医学放射線学会  

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Language：Japanese   Publisher：(公社)日本医学放射線学会  

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Language：Japanese   Publisher：(公社)日本医学放射線学会  

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DOI： 10.2320/matertrans.M-M2023810

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Publisher：学研メディカル秀潤社  

DOI： 10.15105/gz.0000004316

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)   Publisher：European Journal of Radiology  

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

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DOI： 10.2196/41586

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Neuroradiology  

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%, ATT = 1812 ± 353 ms) than in areas where it was preserved (CVR > 18.4%, ATT = 1301 ± 437 ms, P < 0.001). The ROC analysis showed a moderate accuracy (AUC = 0.807, sensitivity = 87.7%, specificity = 70.4%) 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

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DOI： 10.1371/journal.pone.0274610

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Language：Japanese   Publisher：(公社)日本医学放射線学会  

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DOI： 10.1111/jop.13336

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Language：Japanese   Publisher：断層映像研究会  

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Language：Japanese   Publisher：(株)インナービジョン  

arterial spin labeling(以下、ASL)は動脈血中のプロトンのスピンをラベルし、それを内因性トレーサーとして画像化に利用する非侵襲的手法である。近年、臨床現場では、pseudo-continuous ASL(以下、pCASL)の導入により、ASLを用いた脳灌流画像の使用が普及しつつある。臨床で用いられるASLは、通常1つのlabel duration(以下、LD)と1つのpost-labeling delay(以下、PLD)の組み合わせによる1時相での撮像であるが、ラベルされた血液がラベル面から脳組織に到達するまでの時間(arterial transit time:ATT)が長く、ラベルされた血液が到達していない場合には、正しく脳血流量(cerebral blood flow:CBF)を評価することができない。最近では、多時相撮像を行うことでATTの影響を考慮したCBFの定量化が行われるようになってきている。また、ASLは脳灌流画像のみでなく、MR angiography(以下、MRA)にも応用することができる。臨床で用いられるtime of flight(以下、TOF)-MRAは撮像スラブへのinflow効果に依存しているため、上方向以外の血流、乱流、遅い血流などの描出は不良であることや、時間情報を持っていないという欠点がある。ASLによる4D-MRAは、TOF-MRAの弱点を克服しつつ時間情報を有する画像法である。さらに、血管選択的画像も取得することができ、選択的digital subtraction angiography(以下、DSA)の代替となるような画像も得られる。本稿では、多時相ASL灌流画像とASLを用いた4D-MRAの開発の最近の動向と、それらの臨床的有用性を概説する。(著者抄録)

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DOI： 10.3233/SHTI220700

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Language：English  

DOI： 10.3233/SHTI220053

PubMed

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Scientific Reports  

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%, 100%, 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% 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

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DOI： 10.1002/epi4.12616

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：European Radiology  

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%, which was higher than that of the observer test (mean ± standard deviation; 88.7 ± 3.7%). 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

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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

Language：Japanese   Publisher：(株)日本臨床社  

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DOI： 10.1111/1346-8138.16293

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DOI： 10.1002/smll.202106401

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Language：Japanese   Publisher：(公社)日本医学放射線学会  

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Language：Japanese   Publisher：(株)日本臨床社  

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Language：Japanese   Publisher：(公社)日本医学放射線学会  

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DOI： 10.1371/journal.pone.0266141

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DOI： 10.1016/j.cmpbup.2022.100061

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Language：English  

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

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s00330-020-07389-1

Language：English   Publishing type：Research paper (scientific journal)  

Objective To clarify the relationship between amide proton transfer-weighted (APTW) signal, which reflects intracellular pH, and clinico-radiological findings in patients with hyperacute to subacute cerebral infarction. Materials and methods Twenty-nine patients (median age, 70 years [IQR, 54 to 74]; 15 men) were retrospectively examined. The 10th, 25th, 50th, 75th, and 90th percentiles of APTW signal (APT10, APT25, APT50, APT75 and APT90, respectively) were measured within the infarction region-of-interest (ROI), and compared between poor prognosis and good prognosis groups (modified Rankin Scale [mRS] score ≥2 and mRS score <2, respectively). Correlations between APTW signal and time after onset, lesion size, National Institutes of Health Stroke Scale (NIHSS) score, mRS score, and mean apparent diffusion coefficient (ADC) were evaluated. Results The poor prognosis group had lower APT50, APT75 and APT90 than the good prognosis group (-0.66 [-1.19 to -0.27] vs. -0.09 [-0.62 to -0.21]; -0.27 [-0.63 to -0.01] vs. 0.31 [-0.15 to 1.06]; 0.06 [-0.21 to 0.34] vs. 0.93 [0.36 to 1.50] %; p <0.05, respectively). APT50 was positively correlated with time after onset (r = 0.37, p = 0.0471) and negatively with lesion size (r = -0.39, p = 0.0388). APT75 and APT90 were negatively correlated with NIHSS (r = -0.41 and -0.43; p <0.05, respectively). APT50, APT75 and APT90 were negatively correlated with mRS (r = -0.37, -0.52 and -0.57; p <0.05, respectively). APT10 and APT25 were positively correlated with mean ADC (r = 0.37 and 0.38; p <0.05, respectively). Conclusion We demonstrated correlations between APTW signals of infarctions and clinico-radiological findings in patients with hyperacute to subacute infarctions. The poor prognosis group had a lower APTW signal than the good prognosis group. APTW signal was reduced in large infarctions, infarctions with low ADC, and in patients with high NIHSS and mRS scores.

DOI： 10.1371/journal.pone.0237358

Language：English   Publishing type：Research paper (scientific journal)  

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%: 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

Language：English   Publishing type：Research paper (scientific journal)  

Objective: To identify abnormalities of regional cerebral blood flow (rCBF) in individuals with obsessive- compulsive disorder (OCD) by conducting a voxel-based analysis of pseudo-continuous arterial spin labeling (pCASL) perfusion images. Materials and methods: This prospective study included 23 OCD patients (nine males, 14 females; age 21-62 years; mean ± SD 37.2 ± 10.7 years) diagnosed based on DSM-IV-TR criteria and 64 healthy controls (27 males, 37 females; age 20-64 years; mean ± SD 38.3 ± 12.8 years). Subjects were recruited from October 2011 to August 2017. Imaging was performed on a 3T scanner. Quantitative rCBF maps generated from pCASL images were co-registered and resliced with the three-dimensional T1-weighted images, and then spatially normalized to a brain template and smoothed. We used statistical nonparametric mapping to assess the differences in rCBF and gray matter volume between the OCD and control groups. The significance level was set at the p-value <0.05 with family-wise error rate correction for multiple comparisons. Results: Compared to the control group, there were significant rCBF reductions in the right putamen, right frontal operculum, left midcingulate cortex, and right temporal pole in the OCD group. There were no significant between-group differences in the gray matter volume. Conclusion: The pCASL imaging noninvasively detected physiologically disrupted areas without structural abnormalities in OCD patients. The rCBF reductions observed in these regions in OCD patients could be associated with the pathophysiology of OCD.

DOI： 10.1371/journal.pone.0236512

Language：English   Publishing type：Research paper (scientific journal)  

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%, observer 1) and 42/45 (93.3%, 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% and 100% on 4D-PACK, and 100% and 100% on 4D-S-PACK, respectively. For venous drainage, the sensitivity and specificity was 100% on both methods for observer 1. The sensitivity and specificity for observer 2 was 94.4% and 83.3% on 4D-PACK, and 94.4% and 91.7% 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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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
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), 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
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, and f corresponds to the difference between the intercept of this line and SI at the b-value of 0 sec/mm
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. 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
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mm
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/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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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/mm
²
. The voxel size was 1.5 × 1.5 × 1.5 mm
³
, 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
mm
²
/s) was statistically significantly lower than that of solid tumors (1.43 ± 0.41 × 10
⁻³
mm
²
/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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

Chemical exchange saturation transfer (CEST) imaging has been demonstrated to discuss the concentration changes of amide proton, glutamate, creatine, or glucose measured at 3.5, 3.0, 2.0, and 1.0-1.2 ppm. However, these peaks in z-spectra are quite broad and overlap with each other, and thus, the independence of a CEST signal on any specific metabolite is still open to question. Here, we described whether there was interference among the CEST signals and how these CEST signals behave when the power of the presaturation pulse was changed. Based on these results, further experiments were designed to investigate a method to increase the independence of the CEST signal in both phantoms and animals. The result illustrates a clear interference among CEST signals. A presaturation power adjusted pulsed-(PPAP-) CEST method which was designed based on the exchange rates of the metabolites can be used to remove contributions from other exchanging species in the same sample. Further, the method was shown to improve the independence of the glutamate signal in vivo in the renal medulla in mice. The PPAP-CEST method has the potential to increase the independence of any target CEST signals in vivo by choosing the appropriate combination of pulse amplitudes and durations.

DOI： 10.1155/2018/3141789

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1259/bjrcr.20150497

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

A 34-year-old man presented with an acute onset of upbeat nystagmus, slurred speech, and limb and truncal ataxias. The patient had a history of limb ataxia and gait disturbance previously treated as brainstem encephalitis with corticosteroids 3 years previously. Brain magnetic resonance imaging showed pontine developmental venous anomaly (DVA) and hemorrhagic infarction within the drainage territory of the DVA. Three months later, the patient exhibited recurrent limb ataxia, double vision, and numbness of the left side of the body. The brain magnetic resonance imaging revealed recurrent hemorrhagic venous infarction within the same territory of the pontine DVA. Laboratory tests disclosed a hypercoagulable state owing to a decrease of protein S activity despite the normal antigen level. Genetic testing indicated that the patient was a homozygous carrier of protein S Tokushima. The patient's severe disability remained unchanged in spite of treatment with anticoagulation therapy using warfarin. We propose that further research on hereditary coagulopathy be carried out in patients with recurrent episodes of DVA-related infarction.

DOI： 10.1016/j.jstrokecerebrovasdis.2016.08.040

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s00062-013-0254-6

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

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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

Language：English   Publishing type：Research paper (scientific journal)  

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

Language：English   Publishing type：Research paper (scientific journal)  

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

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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.

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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

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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

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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

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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

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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

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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

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A 68-year-old woman had throat pain while eating fish. The pain gradually disappeared with no treatment. She visited her doctor for a medical checkup 1 year later, and an esophageal tumor was suspected. A double-contrast esophagogram revealed luminal stenosis with a mass-like defect in the middle esophagus. Esophagogastroduodenoscopy (EGD) showed smooth-surface stenosis with a retracted fold. Endoscopic ultrasonography (EUS) showed a hypoechoic mass in the submucosal layer and a well-defined linear hyperechoic structure forming a posterior acoustic shadow within the mass. A computed tomography (CT) examination was then performed using an Aquilion 64-detector row CT scanner, and a high attenuation linear structure was found in the lesion that was visualized as a fish bone-like structure on reconstructed CT images. Endoscopic removal of the fish bone was impossible, and a surgical operation would have been too invasive for a lesion suspected of being benign. The patient had no complaint related to the esophageal lesion itself and no sign of gastrointestinal tract complications. Accordingly, regular follow-up was recommended for the esophageal lesion. Follow-up examination including EGD, esophagography, and CT performed 1 year later showed that the lesion had decreased in size with no fish bone-like structure.

DOI： 10.1007/s11604-010-0495-0

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During early development, centrally projecting dorsal root ganglion (DRG) neurons extend their axons toward the dorsal spinal cord. We previously reported the involvement of dorsal spinal cord-derived chemoattraction in this projection (Masuda et al. [2007] Neuroreport 18:1645-1649). However, the molecular nature of this attraction is not clear. Here we show that laminin-1 (α1β1γ1) is expressed strongly along the pathway of DRG axons and that its 67-kDa receptor (67LR) is present on DRG cells. This evidence suggests that laminin-1-67LR signaling may be involved in DRG axonal guidance. By employing culture assays, we show that laminin-1 or the YIGSR peptide, a soluble peptide of the laminin β1 chain, promotes the DRG axonal response to dorsal spinal cord-derived chemoattraction. By using a function-blocking antibody against 67LR, we show that the anti-67LR antibody blocks the modulation of DRG axonal response by the YIGSR peptide in vitro. Furthermore, the in ovo injection of the anti-67LR antibody inhibits the DRG axonal growth toward the dorsal spinal cord. These results provide evidence that the YIGSR peptide promotes dorsal spinal cord-derived chemoattraction via 67LR to contribute to the formation of the initial trajectories of developing DRG axons.

DOI： 10.1002/jnr.21868

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arterial spin labeling(以下、ASL)は動脈血中のプロトンのスピンをラベルし、それを内因性トレーサーとして画像化に利用する非侵襲的手法である。近年、臨床現場では、pseudo-continuous ASL(以下、pCASL)の導入により、ASLを用いた脳灌流画像の使用が普及しつつある。臨床で用いられるASLは、通常1つのlabel duration(以下、LD)と1つのpost-labeling delay(以下、PLD)の組み合わせによる1時相での撮像であるが、ラベルされた血液がラベル面から脳組織に到達するまでの時間(arterial transit time:ATT)が長く、ラベルされた血液が到達していない場合には、正しく脳血流量(cerebral blood flow:CBF)を評価することができない。最近では、多時相撮像を行うことでATTの影響を考慮したCBFの定量化が行われるようになってきている。また、ASLは脳灌流画像のみでなく、MR angiography(以下、MRA)にも応用することができる。臨床で用いられるtime of flight(以下、TOF)-MRAは撮像スラブへのinflow効果に依存しているため、上方向以外の血流、乱流、遅い血流などの描出は不良であることや、時間情報を持っていないという欠点がある。ASLによる4D-MRAは、TOF-MRAの弱点を克服しつつ時間情報を有する画像法である。さらに、血管選択的画像も取得することができ、選択的digital subtraction angiography(以下、DSA)の代替となるような画像も得られる。本稿では、多時相ASL灌流画像とASLを用いた4D-MRAの開発の最近の動向と、それらの臨床的有用性を概説する。(著者抄録)

Language：Japanese   Publisher：(株)日本臨床社  

Language：Japanese   Publisher：(株)日本臨床社  

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皮質下白質の拡散能に高度な左右差を認めた皮質基底核変性症の1例