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

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

Introduction: Radioiodine therapy with ¹³¹I (¹³¹I therapy) after total or near-total thyroidectomy has been established as an effective treatment for Differentiated Thyroid Carcinoma (DTC), but can induce dry mouth symptoms by salivary gland damage and impair the patients’ quality of life. Aim: To propose a functional scoring system based on Salivary Gland Scintigraphy (SGS) findings that evaluates development of salivary gland dysfunction secondary to ¹³¹I therapy in patients with DTC. Materials and Methods: This retrospective study evaluated the records of 279 DTC patients who underwent SGS after one or more round(s) of ¹³¹I therapy, using 370 MBqof ^99mTc-pertechnetate. The SGS results were assessed using a novel functional scoring system in the Parotid Glands (PGs) and Submandibular Glands (SMGs) according to visual evaluations based on a three-point uptake score, Washout Rate (%WR) score after lemon-juice stimulation, and functional score. The scores were compared among pretreatment, low-dose (<10 GBq), and high-dose (>10 GBq) groups and among pretreatment, symptom-positive, and symptom-negative groups. Risk factors for dry mouth were analyzed by univariate and multivariate logistic regression analyses. Results: Dry mouth symptoms developed in 15.4% of the DTC patients after ¹³¹I therapy. The three-point uptake, %WR, and functional scores in both the PG and SMG were statistically significant between low-dose and high-dose groups, and between symptom-positive and symptom-negative groups. The PG/SMG functional scores were independent risk factors for dry mouth (odds ratio, 0.03 and 0.0007 respectively). Conclusion: SGS-based PG and SMG functional scores were effective biomarkers to objectively evaluate salivary gland dysfunction, with the high strength of association with dry mouth symptoms.

DOI： 10.7860/JCDR/2017/27340.10431

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Purpose: Lung metastases (LMs) and their radioiodine uptake affect prognosis in patients with differentiated thyroid carcinoma (DTC). We herein investigate the value of metabolic tumor volume (MTV) in LMs on positron emission tomography/computed tomography (PET/CT) using 2-[F-18]-fluoro-2-deoxy-D-glucose (F-18 FDG PET/CT) in predicting short-term progression after initial I-131 therapy in DTC patients. Materials and Methods: We retrospectively evaluated 111 DTC patients with LMs. Diagnostic CT and I-131 scintigraphy were performed within 1 week of I-131 therapy. Maximum standardized uptake value (SUVmax) and total MTV (MTVtotal) were compared between patients with I-131-positive and I-131-negative LMs and between patients with and without short-term progression. Correlation analyses were performed between F-18 FDG PET/CT parameters and thyroglobulin (TG) level, and predictive factors for short-term progression were analyzed by logistic regression and receiver operating characteristic curve analysis.Results: Patients with short-term progression had significantly higher SUVmax and MTVtotal than those without. TG levels were significantly correlated with SUVmax (r = 0.21) and MTVtotal (r = 0.51) after I-131 therapy. MTVtotal showed significant association (χ² = 16.5, odds ratio = 0.02) with short-term progression after initial I-131 therapy and had the highest predictive value of all the putative risk factors. Conclusions: MTVtotal in LMs on F-18 FDG PET/CT is an independent predictive factor with a high predictive value for short-term progression of DTC after initial I-131 therapy. It is recommended that F-18 FDG PET/CT be performed before planning therapy during the evaluation of DTC patients with LM.

DOI： 10.4103/ijnm.IJNM_43_17

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

Objectives: Radioiodine therapy is an effective treatment for lung metastasis from thyroid cancer. However, cases of lung metastasis without iodine uptake are often encountered. In such cases, FDG accumulation in lung lesions is often observed. There is a reverse relationship between iodine and FDG accumulation in thyroid cancer lesions, the so-called “flip-flop” phenomenon. The aim of this study was to assess the relationship between patient age and the occurrence of the flip-flop phenomenon. Methods: Eighty-six patients who underwent radioiodine therapy for lung metastasis were studied retrospectively (age 17–73 years; median 60 years; males:females 22:64). We compared the clinical data and imaging findings (size and FDG uptake of lung nodules) between patients with (n = 44) and without (n = 42) iodine uptake in lung metastasis. Results: Significantly more young patients showed iodine accumulation in lung metastasis than old patients (p = 0.0025). Lung metastases with larger size or greater FDG uptake showed no iodine uptake more frequently with significant difference (p = 0.015 and <0.001, respectively). Among patients with FDG uptake in the lung metastasis, 57.1 % of young patients (<60 years) and 24.3 % of the old patients (≥60 years) showed iodine uptake (p = 0.0029). Conclusions: Higher patient age and lung nodules with large size or FDG accumulation are negative factors for iodine accumulation in lung metastases from thyroid cancer. In addition, our results show that young patients have a greater likelihood of iodine uptake even when FDG accumulates in lung metastasis, in contrast to old patients.

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

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

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

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

PURPOSE:
The purpose of this study was to evaluate the clinical usefulness of partial volume effect (PVE)-corrected F-18 FDG PET/CT for predicting I-131 accumulation in metastatic lymph nodes (mLNs) during I-131 therapy for papillary thyroid carcinoma (PTC).

METHODS:
Sixty-five mLNs in 31 PTC patients who underwent F-18 FDG PET/CT in an initial radioiodine therapy (RIT) were retrospectively evaluated. Of these, 25 mLNs were I-131-positive and 40 were I-131-negative. SUVmax and SUVmax with PVE correction (cSUVmax) were measured for each mLN, where PVE correction was performed utilizing a simple table lookup correction method. Then, SUVmax/cSUVmax was compared between I-131-positive and I-131-negative mLNs, including the analyses for the mLNs with small-sized (<1 cm) and weak FDG accumulation (SUVmax <3.5). The predictability for I-131 accumulation with SUVmax/cSUVmax was also compared.

RESULTS:
For all 65 mLNs, SUVmax/cSUVmax was significantly higher in I-131-negative than I-131-positive mLNs (p < 0.0001). Only in cSUVmax, I-131-negative mLNs were significantly higher than I-131-positive, in terms of the 30 small-sized mLNs (p = 0.0001) and 14 mLNs with weak FDG uptake (p = 0.007). The highest accuracy in predictability for I-131 accumulation was significantly better with cSUVmax (92 %) than SUVmax (62 %) (p < 0.0001).

CONCLUSION:
PVE-corrected F-18 FDG PET/CT is a valuable predictor of I-131 accumulation in mLNs during RIT.

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Purpose
The purpose of this study was to investigate the effects of point-spread function (PSF) and time-of-flight (TOF) on the standardized uptake value (SUV) of lymph node metastasis in FDG-PET/CT.

Materials and methods
This study evaluated 41 lymph node metastases in 15 patients who had undergone 18F-FDG PET/CT. The lesion diameters were 2.5 cm or less. The mean short-axis diameter of the lymph nodes was 10.5 ± 3.7 mm (range 4.6–22.8 mm). The PET data were reconstructed with baseline OSEM algorithm, with OSEM + PSF, with OSEM + TOF and with OSEM + PSF + TOF. A semi-quantitative analysis was performed using the maximum and mean SUV of lymph node metastases (SUVmax and SUVmean) and mean SUV of normal lung tissue (SUVlung). We also evaluated image quality using the signal-to-noise ratio in the liver (SNRliver).

Results
Both PSF and TOF increased the SUV of lymph node metastases. The combination of PSF and TOF increased the SUVmax by 43.3% and the SUVmean by 31.6% compared with conventional OSEM. By contrast, the SUVlung was not influenced by PSF and TOF. TOF significantly improved the SNRliver.

Conclusion
PSF and TOF both increased the SUV of lymph node metastases. Although PSF and TOF are considered to improve small-lesion detectability, it is important to be aware that PSF and TOF influence the accuracy of quantitative measurements.

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

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

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

Effect of Nicotine and Ephedrine on the Accumulation of FDG in Brown Adipose Fat Tissue

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

Relapsed and refractory aggressive lymphoma have a poor prognosis. High-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (auto-HSCT) is effective in chemosensitive patients. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is among the few options for non-chemosensitive patients. 18Fluoro-2-deoxy-D-glucose positron emission tomography-computed tomography (18FDG-PET/CT) is the standard tool for evaluating response to chemotherapy and residual tumor volume. However, accurate assessment of residual tumor volume is not currently being achieved in clinical practice, and its value in prognostic and therapeutic stratification remains unclear. To answer this question, we investigated the efficacy of quantitative indicators, including total metabolic tumor volume (TMTV), in predicting prognosis after auto-HSCT and allo-HSCT. We retrospectively analyzed 39 patients who received auto-HSCT and 28 who received allo-HSCT. In the auto-HSCT group, patients with a higher TMTV had a poor prognosis due to greater risk of relapse. In the allo-HSCT group, patients with a higher TMTV had a lower progression-free survival rate and a significantly higher relapse rate. Neither Deauville score nor other clinical parameters were associated with prognosis in either group. Therefore, pre-transplant TMTV on PET is effective for prognostic prediction and therapeutic decision-making for relapsed or refractory aggressive lymphoma.

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Background While current guidelines require lung ventilation-perfusion (V/Q) scanning as the first step to diagnose chronic pulmonary embolism in pulmonary hypertension (PH), its use may be limited by low availability and/or exposure to ionizing radiation. Purpose To compare the performance of dynamic chest radiography (DCR) and lung V/Q scanning for detection of chronic thromboembolic PH (CTEPH). Materials and Methods Patients with PH who underwent DCR and V/Q scanning in the supine position from December 2019 to July 2021 were retrospectively screened. The diagnosis of CTEPH was confirmed with right heart catheterization and invasive pulmonary angiography. Observer tests were conducted to evaluate the diagnostic accuracy of DCR and V/Q scanning. The lungs were divided into six areas (upper, middle, and lower for both) in the anteroposterior image, and the number of lung areas with thromboembolic perfusion defects was scored. Diagnostic performance was compared between DCR and V/Q scanning using the area under the receiver operating characteristic curve. Agreement between the interpretation of DCR and that of V/Q scanning was assessed using the Cohen kappa coefficient and percent agreement. Results A total of 50 patients with PH were analyzed: 29 with CTEPH (mean age, 64 years ± 15 [SD]; 19 women) and 21 without CTEPH (mean age, 61 years ± 22; 14 women). The sensitivity, specificity, and accuracy of DCR were 97%, 86%, and 92%, respectively, and those of V/Q scanning were 100%, 86%, and 94%, respectively. Areas under the receiver operating characteristic curve for DCR and V/Q scanning were 0.92 (95% CI: 0.79, 0.97) and 0.93 (95% CI: 0.78, 0.98). Agreement between the consensus interpretation of DCR and that of V/Q scanning was substantial (κ = 0.79 [95% CI: 0.61, 0.96], percent agreement = 0.9 [95% CI: 0.79, 0.95]). Conclusion Dynamic chest radiography had similar efficacy to ventilation-perfusion scanning in the detection of chronic thromboembolic pulmonary hypertension. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Wandtke and Koproth-Joslin in this issue.

DOI： 10.1148/radiol.220908. Epub 2022 Nov 8.

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211At is a promising nuclide for targeted radioisotope therapy. Direct imaging of this nuclide is important for in vivo evaluation of its distribution. We investigated suitable conditions for single-photon emission computed tomography (SPECT) imaging of 211At and assessed their feasibility using a homemade Monte Carlo simulation code, MCEP-SPECT. Radioactivity concentrations of 5, 10, or 20 kBq/mL were distributed in six spheres in a National Electrical Manufactures Association (NEMA) body phantom with a background of 1 kBq/mL. The energy window, projection number, and acquisition time were 71-88 keV, 60, and 60 s, respectively, per projection. A medium-energy collimator and three low-energy collimators were tested. SPECT images were reconstructed using the ordered subset expectation maximization (OSEM) method with attenuation correction (Chang method) and scatter correction (triple-energy-windows method). Image quality was evaluated using the contrast-to-noise ratio (CNR) for detectability and the contrast recovery coefficient (CRC) for quantitavity. The low-energy, high-sensitivity collimator exhibited the best detectability among the four types of collimators, with a maximum CNR value of 43. In contrast, the low-energy, high-resolution collimator exhibited excellent quantitavity, with a maximum CRC value of 102%. Scatter correction improved the image quality. In particular, the CRC value almost doubled after scatter correction. The detection of spheres smaller than 20 mm in diameter was difficult. In summary, low-energy collimators were suitable for the SPECT imaging of 211At. In addition, scatter correction was extremely effective in improving the image quality. The feasibility of 211At SPECT was demonstrated for lesions larger than 20 mm.

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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.

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Purpose: To evaluate the clinical significance of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in patients with pancreatic ductal adenocarcinoma who underwent neoadjuvant therapy.

Methods: Among 285 consecutive patients who underwent pancreatic resection for pancreatic ductal adenocarcinoma between 2015 and 2021, 86 who underwent preoperative 18F-fluorodeoxyglucose positron emission tomography/computed tomography after completion of neoadjuvant treatment were reviewed. Among preoperative factors, including post-treatment maximum standardized uptake value, predictors of early recurrence and poor prognosis were identified using multivariate analysis for decision making in surgery.

Results: Nineteen (22%) patients with pancreatic ductal adenocarcinoma demonstrated high maximum standardized uptake (≥ 4.5). High post-treatment maximum standardized uptake (≥ 4.5) predicted early recurrence within 6 months after surgery and correlated with shorter recurrence-free survival. Elevated post-treatment CA19-9 level (> 37 U/ml) and maximum standardized uptake ≥ 4.5 were independent prognostic factors. Post-treatment, a high maximum standardized uptake value indicated a poorer prognosis than a low maximum standardized uptake value in both patients with elevated CA19-9 and normal CA19-9 levels. The median overall survival in patients with elevated post-treatment CA19-9 and high maximum standardized uptake was only 17 months; 67% experienced early recurrence. Dynamic changes in maximum standardized uptake during neoadjuvant therapy were correlated with pathological response to neoadjuvant therapy, but not with radiological response or change in CA19-9 level.

Conclusions: Post-treatment assessment using maximum standardized uptake value is useful for stratifying patients with pancreatic ductal adenocarcinoma who will benefit from surgery. Instead of subsequent curative resection, additional neoadjuvant therapy should be considered in patients with a persistently high maximum standardized uptake value.

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PET can reveal in vivo biological processes at the molecular level. PET-derived quantitative values have been used as a surrogate marker for clinical decision-making in numerous clinical studies and trials. However, quantitative values in PET are variable depending on technical, biological, and physical factors. The variability may have a significant impact on a study outcome. Appropriate scanner calibration and quality control, standardization of imaging protocols, and any necessary harmonization strategies are essential to make use of PET as a biomarker with low bias and variability. This review summarizes benefits, limitations, and remaining challenges for harmonization of quantitative PET, including whole-body PET in oncology, brain PET in neurology, PET/MR, and non-18F PET imaging. This review is expected to facilitate harmonization of quantitative PET and to promote the contribution of PET-derived biomarkers to research and development in medicine.

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Purpose: Although a novel deep learning software was proposed using post-processed images obtained by the fusion between X-ray images of normal post-operative radiography and surgical sponge, the association of the retained surgical item detectability with human visual evaluation has not been sufficiently examined. In this study, we investigated the association of retained surgical item detectability between deep learning and human subjective evaluation.

Methods: A deep learning model was constructed from 2987 training images and 1298 validation images, which were obtained from post-processing of the image fusion between X-ray images of normal post-operative radiography and surgical sponge. Then, another 800 images were used, i.e., 400 with and 400 without surgical sponge. The detection characteristics of retained sponges between the model and a general observer with 10-year clinical experience were analyzed using the receiver operator characteristics.

Results: The following values from the deep learning model and observer were, respectively, derived: Cutoff values of probability were 0.37 and 0.45; areas under the curves were 0.87 and 0.76; sensitivity values were 85% and 61%; and specificity values were 73% and 92%.

Conclusion: For the detection of surgical sponges, we concluded that the deep learning model has higher sensitivity, while the human observer has higher specificity. These characteristics indicate that the deep learning system that is complementary to humans could support the clinical workflow in operation rooms for prevention of retained surgical items.

DOI： doi: 10.1007/s11548-022-02816-8.

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Background: Preoperative maximum standardized uptake value (SUVmax) of 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography and serum carcinoembryonic antigen (CEA) have been reported as prognostic factors for lung adenocarcinoma. However, the significance of combined SUVmax and CEA in early-stage lung adenocarcinoma is not well known.

Methods: We retrospectively evaluated the relationship between the combination of SUVmax and CEA and the prognosis of 410 patients with clinical stage IA lung adenocarcinoma who underwent resection. The cutoff values for SUVmax and CEA were determined by receiver operating characteristic curve analysis, and patients were categorized into high SC (SUVmax and CEA) group (SUVmax ≥2.96 and CEA ≥5.3), moderate SC group (either SUVmax <2.96 and CEA ≥5.3 or SUVmax ≥2.96 and CEA <5.3) and low SC group (SUVmax <2.96 and CEA <5.3).

Results: Kaplan-Meier curve analysis showed that patients with clinical stage IA lung adenocarcinoma in the high SC group had significantly shorter overall survival (OS) and recurrence-free survival (RFS) than the other groups (p = 0.011 and p < 0.0001, respectively). Multivariate analysis showed that high SC was an independent prognostic factor of OS (p = 0.029) and RFS (p < 0.0001).

Conclusions: High values of SUVmax and CEA were associated with poor OS and RFS in patients with stage IA lung adenocarcinoma. Simultaneous evaluation of SUVmax and CEA may be an effective prognostic marker to determine the optimal treatment strategy of early-stage lung adenocarcinoma.

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Aim: To determine whether the pathological response to preoperative chemotherapy for pancreatic ductal adenocarcinoma (PDAC) can be predicted using 2-[18F]-fluoro-2-deoxy-d-glucose positron-emission tomography (F-18 FDG-PET).

Materials and methods: Twenty-eight patients with PDAC who underwent only neoadjuvant chemotherapy (NAC) before surgery were enrolled in the study. All patients had F-18 FDG-PET examinations before NAC. The resected specimen was pathologically evaluated according to the Classification of Pancreatic Carcinoma (7th edn). Patients were categorised into a non-response group and a response group based on the pathological findings. The non-response group (Grades 1a and 1b) showed ≤50% necrosis in the specimen, while the specimens of the response group (Grades 2-3) showed >50% necrosis. The maximum standardised uptake values (SUVmax) of the tumours on F-18 FDG-PET were measured. The mean values of SUVmax were compared between the two groups. The diagnostic performance of SUVmax in distinguishing the two groups was also evaluated using receiver operating characteristic analysis.

Results: The mean SUVmax of the response group was higher than that of the non-response group (9.00 ± 1.78 versus 4.26 ± 2.35; p<0.001). The optimal cut-off value of SUVmax was 9.28 for distinguishing the two groups. The sensitivity, specificity, and accuracy for the prediction in the response group were 80%, 95.7%, and 92.9%, respectively.

Conclusions: SUVmax on F-18 FDG-PET may be useful as a biomarker to predict the pathological response to NAC in patients with PDAC.

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We examined phosphorylated nuclear factor erythroid 2-related factor 2 (P-NRF2) expression in surgically resected primary hepatocellular carcinoma (HCC) and investigated the association of P-NRF2 expression with clinicopathological features and patient outcome. We also evaluated the relationship among NRF2, cancer metabolism, and programmed death ligand 1 (PD-L1) expression. In this retrospective study, immunohistochemical staining of P-NRF2 was performed on the samples of 335 patients who underwent hepatic resection for HCC. Tomography/computed tomography using fluorine-18 fluorodeoxyglucose was performed, and HCC cell lines after NRF2 knockdown were analyzed by array. We also analyzed the expression of PD-L1 after hypoxia inducible factor 1α (HIF1A) knockdown in NRF2-overexpressing HCC cell lines. Samples from 121 patients (36.1%) were positive for P-NRF2. Positive P-NRF2 expression was significantly associated with high alpha-fetoprotein (AFP) expression, a high rate of poor differentiation, and microscopic intrahepatic metastasis. In addition, positive P-NRF2 expression was an independent predictor for recurrence-free survival and overall survival. NRF2 regulated glucose transporter 1, hexokinase 2, pyruvate kinase isoenzymes L/R, and phosphoglycerate kinase 1 expression and was related to the maximum standardized uptake value. PD-L1 protein expression levels were increased through hypoxia-inducible factor 1α after NRF2 overexpression in HCC cells. Conclusions: Our large cohort study revealed that P-NRF2 expression in cancer cells was associated with clinical outcome in HCC. Additionally, we found that NRF2 was located upstream of cancer metabolism and tumor immunity.

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This study investigated the spatial resolution and image quality of the continuous bed motion (CBM) method in a sensitive silicon photomultiplier (SiPM)-based positron emission tomography (PET)/computed tomography (CT) system compared with the traditional step-and-shoot (SS) method. Methods: Siemens Biograph Vision was used in this study. Data acquisition using the SS method was performed for 3 min per bed. In the CBM method, the bed speed ranged from 0.5 to 3.3 mm/s. The acquisition time equivalent to the SS method was 1.1 mm/s for 2-bed ranges and 0.8 mm/s for seven-bed ranges. The spatial resolution was investigated using 18F point sources and evaluated using the full width at half maximum. Image quality was investigated using a National Electrical Manufacturers Association International Electrotechnical Commission body phantom with six spheres 10-, 13-, 17-, 22-, 28-, and 37-mm inner diameters. The radioactivity concentration ratio of the 18F solution in all spheres and the background was approximately 4:1. The detectability of each sphere was visually evaluated on a five-step score. Image quality was physically evaluated using the noise equivalent count rate (NECphantom), contrast percentage of the 10-mm hot sphere (QH,10mm), background variability percentage (N10mm), and contrast-noise ratio (QH,10mm/N10mm). Results: The spatial resolution was not affected by the difference of acquisition methods and bed speeds. The detectability of the 10-mm sphere with a bed speed of 2.2 mm/s or faster was significantly inferior to that of the SS 2-bed method. In evaluating image quality, no significant difference in the contrast percentage was observed among the acquisition methods and speeds in the CBM method. However, the increasing bed speed in the CBM method increased the N10mm and decreased the NECphantom. When comparing the SS 2-bed method with the CBM method at 0.8 mm/s, no significant differences in all parameters were observed. Conclusion: In a SiPM-based PET/CT scanner, the CBM method provides equivalent spatial resolution and image quality in whole body PET images with same acquisition time using the SS method.

DOI： doi: 10.2967/jnmt.121.263240.

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Objective: Sentinel node biopsy alone (SNB) reduces the postoperative complications of pelvic lymphadenectomy, such as lymphedema and lymphangitis; however, the long-term prognosis after SNB is unclear. The objective of this study was to evaluate the long-term outcome and complications of patients with early-stage cervical cancer who underwent SNB for hysterectomy or trachelectomy.

Methods: We performed SNB for cervical cancer using a radioisotope method in 181 patients between 2009 and 2017. If the intraoperative sentinel lymph node evaluation was negative for metastasis, no further lymph nodes were removed.

Results: The median age of the patients was 34 years (range, 21-73 years). The International Federation of Gynecology and Obstetrics 2008 stage was IA1 in 6 patients, IA2 in 18, IB1 in 154, and IIA1 in 3. Of the 181 patients (44 with hysterectomy, 137 with trachelectomy), 8 did not undergo pelvic lymphadenectomy because of a false-negative intraoperative diagnosis, 20 received adjuvant therapy after surgery, and 4 (2.2%) experienced recurrence over a median follow-up period of 83.5 months (range, 25-145 months). In the four recurrent cases, recurrence occurred in the pelvis, lung, and bone in one patient each, while the remaining patient developed pelvic and para-aortic lymph node metastases. Of these four patients, one died, and the remaining three are alive without disease after multidisciplinary therapy. The 5-year progression-free and overall survival rates were 98.8% and 99.4%, respectively. Postoperative complications, such as lymphedema, were very low rate.

Conclusions: SNB for early-stage cervical cancer might be safe and effective, with no increase in the recurrence and postoperative complications rate.

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

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

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

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

Objectives: To clarify differences in arterial 18F-FDG (fluorodeoxyglucose) uptake between silicon photomultiplier (SiPM)-based and conventional PET/CT scanners, and to compare clinical and phantom results.

Patients and methods: Twenty-six patients with lung tumours underwent serial SiPM-based and conventional PET/CT scans on the same day. We compared the target-to-background ratios [TBRsi (SiPM), TBRc (conventional)] and the percentage difference between TBRsi and TBRc (ΔTBR) in the carotid artery, aorta and peripheral arteries. The correlation between ΔTBR and vessel size was also investigated. In the carotid artery, active segment analyses were performed with the threshold (TBR ≥1.6), and we compared each scanner's ratio of active segments and TBR values. We compared the clinical results with the recovery coefficients (RCs).

Results: The TBRsi was significantly higher than the TBRc in the carotid artery, aorta and peripheral arteries (1.63 ± 0.22 vs. 1.43 ± 0.22, 1.65 ± 0.19 vs. 1.53 ± 0.15 and 1.37 ± 0.31 vs. 1.11 ± 0.27, mean ± SD, P ≤ 0.0001 for all), and the peripheral arteries showed the highest ΔTBR (24.4 ± 16.8%). The small (10-15 mm) vessels (26.9 ± 15.9%) showed significantly higher ΔTBRs than the larger vessels (7.3 ± 8.5% for 15-20 mm, 8.0 ± 12.8% for ≥20 mm, P < 0.0001 for both). The carotid artery showed significantly higher ratios of active segment (54.5 vs. 20.5%, P < 0.0001) and TBR values (1.85 ± 0.25 vs. 1.76 ± 0.15, P = 0.0006) for TBRsi vs. TBRc. The differences in RCs were similar to those of ΔTBR for each vessel size.

Conclusions: SiPM-based PET/CT scanners showed higher arterial 18F-FDG uptake (especially in vessels <15 mm) than conventional scanners, and the threshold TBR ≥1.6 is not applicable for the carotid artery for SiPM-based PET/CT systems.

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

Objective: To examine the impact of acquisition time on Lutetium-177 (177Lu) single-photon emission computed tomography (SPECT) images using Monte Carlo simulation.

Methods: A gamma camera simulation based on the Monte Carlo method was performed to produce SPECT images. The phantom was modeled on a NEMA IEC BODY phantom including six spheres as tumors. After the administration of 7.4 GBq of 177Lu, radioactivity concentrations of the tumor/liver at 6, 24, and 72 h after administration were set to 1.85/0.201, 2.12/0.156, and 1.95/0.117 MBq/mL, respectively. In addition, the radioactivity concentrations of the tumor at 72 h after administration varied by 1/2, 1/4, and 1/8 when comparison was made. Acquisition times examined were 1.2, 1.5, 2, 3, 6, and 12 min. To assess the impact of collimators, SPECT data acquired at 72 h after the administration using six collimators of low-energy high-resolution (LEHR), extended low-energy general-purpose (ELEGP), medium-energy, and general-purpose (MEGP-1, MEGP-2, and MEGP-3) and high-energy general-purpose (HEGP) were examined. After prefiltering using a Butterworth filter, projection images were reconstructed using ordered subset expectation maximization. The detected photons were classified into direct rays, scattered rays, penetrating rays, and characteristic X-rays from lead. The image quality was evaluated through visual assessment, and physical assessment of contrast recovery coefficient (CRC) and contrast-to-noise ratio (CNR). In this study, the CNR threshold for detectability was assumed to be 5.0.

Results: To compare collimators, the highest sensitivity was observed with ELEGP, followed by LEHR and MEGP-1. The highest ratio of direct ray was also observed in ELEGP followed by MEGP-1. In comparison of the radioactivity concentration ratios of tumor/liver, CRC and CNR were significantly decreased with smaller radioactivity concentration ratios. This effect was greater with larger spheres. According to the visual assessment, the acquisition time of 6, 6, and 3 min or longer was required using ELEGP collimator at 6, 24, and 72 h after administration, respectively. Physical assessment based on CNR and CRC also suggested that 6, 6, and 3 min or longer acquisition time was necessary at 6, 24, and 72 h after administration.

Conclusion: 177Lu-SPECT images generated via the Monte Carlo simulation suggested that the recommended acquisition time was 6 min or longer at 6 and 24 h and 3 min or longer at 72 h after administration.

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Objective: The aim of this multicenter prospective study was to compare the sensitivity of 18F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) with that of 67Ga single photon emission computed tomography (SPECT) for the identification of the site of greatest importance for the final diagnosis of the cause of fever of unknown origin (FUO).

Methods: The study participants consisted of patients with an axillary temperature ≥ 38.0 °C on ≥ 2 occasions within 1 week, with repeated episodes for ≥ 2 weeks prior to providing consent, and whose final diagnosis after undergoing specific examinations, including a chest-to-abdomen CT scan, was uncertain. All the patients underwent FDG-PET/CT imaging first, followed by 67Ga-SPECT imaging within 3 days. The results of the FDG-PET/CT and 67Ga-SPECT examinations were reviewed by the central image interpretation committee (CIIC), which was blinded to all other clinical information. The sensitivities of FDG-PET/CT and 67Ga-SPECT were then evaluated with regard to identifying the site of greatest importance for a final diagnosis of the cause of the fever as decided by the patient's attending physician. The clinical impacts (four grades) of FDG-PET/CT and 67Ga-SPECT on the final diagnosis were evaluated.

Results: A total of 149 subjects were enrolled in this study between October 2014 and September 2017. No adverse events were identified among the enrolled subjects. Twenty-one subjects were excluded from the study because of deviations from the study protocol. Among the 128 remaining subjects, a final diagnosis of the disease leading to the appearance of FUO was made for 92 (71.9%) subjects. The final diagnoses in these 92 cases were classified into four groups: noninfectious inflammatory disease (52 cases); infectious disease (31 cases), malignancy (six cases); and other (three cases). These 92 subjects were eligible for inclusion in the study's analysis, but one case did not meet the PET/CT image acquisition criteria; thus, PET/CT results were analyzed for 91 cases. According to the patient-based assessments, the sensitivity of FDG-PET/CT (45%, 95% CI 33.1-58.2%) was significantly higher than that for 67Ga-SPECT (25%, 95% CI 15.5-37.5%) (P = 0.0029). The clinical impact of FDG-PET/CT (91%) was also significantly higher than that for 67Ga-SPECT (57%, P < 0.001).

Conclusions: FDG-PET/CT showed a superior sensitivity to 67Ga-SPECT for the identification of the site of greatest importance for the final diagnosis of the cause of FUO.

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Body mass index (BMI) is well known to be associated with poor prognosis in several cancers. The relationship between BMI and the long-term outcomes of patients with intrahepatic cholangiocarcinoma (ICC) is incompletely understood. This study investigated the relationships of BMI with clinicopathological characteristics and patient outcomes, focusing on metabolic activity and immune status. The relationship between BMI and the maximum standardized uptake value (SUVmax) on fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) was analyzed. In addition, immunohistochemistry was performed for programmed cell death-ligand 1 (PD-L1), cluster of differentiation 8 (CD8), and forkhead box protein P3 (Foxp3). Seventy-four patients with ICC were classified into normal weight (BMI < 25.0 kg/m2, n = 48) and obesity groups (BMI ≥ 25.0 kg/m2, n = 26), respectively. Serum carbohydrate antigen 19-9 levels were higher in the obesity group than in the normal weight group. Tumor size and the intrahepatic metastasis rate were significantly larger in the obesity group. Patients in the obesity group had significantly worse prognoses than those in the normal weight group. Moreover, BMI displayed a positive correlation with SUVmax on 18F-FDG PET/CT (n = 46, r = 0.5152). Patients with high 18F-FDG uptake had a significantly higher rate of PD-L1 expression, lower CD8 + tumor-infiltrating lymphocyte (TIL) counts, and higher Foxp3 + TIL counts. The elevated BMI might predict the outcomes of patients with ICC. Obesity might be associated with ICC progression, possibly through alterations in metabolic activity and the immune status.

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Objectives: To examine the utility of FDG-PET/MRI in patients with epilepsy by comparing the diagnostic accuracy of PET/MRI and PET/CT in epileptogenic zone (EZ) detection.

Methods: This prospective study included 31 patients (17 males, 14 females) who underwent surgical resection for EZ. All patients were first scanned using FDG-PET/CT followed immediately with FDG-PET/MRI. Two series of PET plus standalone MR images were interpreted independently by five board-certified radiologists. A 4-point visual score was used to assess image quality. Sensitivities and visual scores from both PETs and standalone MRI were compared using the McNemar test with Bonferroni correction and Dunn's multiple comparisons test.

Results: The EZs were confirmed histopathologically via resection as hippocampal sclerosis (n = 11, 35.5%), gliosis (n = 8, 25.8%), focal cortical dysplasia (n = 6, 19.4%), and brain tumours (n = 6, 19.4%) including cavernous haemangioma (n = 3), dysembryoplastic neuroepithelial tumour (n = 1), ganglioglioma (n = 1), and polymorphous low-grade neuroepithelial tumour of the young (n = 1). The sensitivity of FDG-PET/MRI was significantly higher than that of FDG-PET/CT and standalone MRI (FDG-PET/MRI vs. FDG-PET/CT vs. standalone MRI; 77.4-90.3% vs. 58.1-64.5% vs. 45.2-80.6%, p < 0.0001, respectively). The visual scores derived from FDG-PET/MRI were significantly higher than those of FDG-PET/CT, as well as standalone MRI (2.8 ± 1.2 vs. 2.0 ± 1.1 vs. 2.1 ± 1.2, p < 0.0001, respectively). Compared to FDG-PET/CT, FDG-PET/MRI increased the visual score (51.9%, increased visual scores of 2 and 3).

Conclusions: The diagnostic accuracy for the EZ detection in focal epilepsy could be higher in FDG-PET/MRI than in FDG-PET/CT.

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We evaluated the prognostic value of fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in hepatocellular carcinoma (HCC). Their association with programmed death ligand 1 (PD-L1) expression and vascular formation was further investigated. In this retrospective study, using a database of 418 patients who had undergone 18F-FDG PET/CT before hepatic resection for HCC, immunohistochemical staining of PD-L1, clusters of differentiation (CD) 8, CD68, and CD34 was performed. Patients with a high maximum standardized uptake value (SUVmax) on 18F-FDG PET/CT showed a significantly worse recurrence-free survival (RFS) (hazard ratio [HR]: 1.500; 95% confidence interval [CI]: 1.088-2.069; P = 0.0133) and overall survival (OS) (HR: 2.259; 95% CI: 1.276-4.000; P = 0.0052) than patients with a low SUVmax. Logistic regression analysis showed that a high SUVmax in HCC was significantly associated with PD-L1-positive expression (odds ratio: 4.407; 95% CI: 2.265-8.575; P < 0.0001). SUVmax values of HCC were associated with intratumoral CD8-positive T-cell counts (P = 0.0044) and CD68-positive macrophage counts (P = 0.0061). Stratification based on SUVmax, PD-L1 expression, and the vessels that encapsulate tumor clusters (VETC) status was also significantly associated with RFS and OS. SUVmax, VETC, and PDL1 expression were independently predictive of survival on multivariable analysis. Conclusion: Our large cohort study showed that a high SUVmax on 18F-FDG PET/CT is associated with a poor clinical outcome and PD-L1 expression in patients with HCC. Additionally, stratification of patients based on the combination of SUVmax, PD-L1 expression, and the VETC status predicts poor clinical outcome.

DOI： https://doi.org/10.1002/hep4.1715

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Objectives: Ra-223 is a promising radionuclide for the treatment of skeletal metastases in castration-resistant prostate cancer patients. This study aims to estimate the lower limits for feasible Ra-223 single-photon emission computerized tomography (SPECT) imaging using a Monte Carlo simulation study.

Methods: The SPECT images were produced on a homemade code: the Monte Carlo simulation of electrons and photons for SPECT (MCEP-SPECT). The National Electrical Manufacturers Association (NEMA) phantom with six hot spheres of diameters of 37, 28, 22, 17, 13, and 10 mm installed inside, was used. The background activity concentration was 0.6 kBq/mL, and the ratios of hot concentrations to the background (R HB) were 25, 20, 15, 10, and 5. When R HB was 15, the background concentrations of 1.5, 0.9, 0.3, and 0.15 kBq/mL were also tested. The energy window was 84 keV±10%. The number of projections was 60/360°, and the acquisition time was 60 s per projection. Two kinds of collimators: middle-energy general-purpose (MEGP) and high-energy general-purpose (HEGP), were examined. The SPECT images were evaluated based on two quantitative indexes: contrast-to-noise ratio (CNR) for detectability and contrast recovery coefficient (CRC) for quantitative accuracy.

Results: The CRC for the HEGP collimator was 35-40%, while the CRC for the MEGP collimator was 25-30%. The CNRs for the MEGP collimator were larger than those for the HEGP collimator. The CNRs of the hot spheres with diameters less than 22 mm were lower than 5.0 for both collimators, when R HB and the background concentration were 15 and 0.6 kBq/mL, respectively. Based on the obtained results, it was estimated that the lower limit of R HB for the detection of the hot sphere with a diameter of 37 mm would be approximately 20 if the background concentration is 0.05 kBq/mL.

Conclusions: The MEGP collimator is superior in terms of detectability, while the HEGP collimator is superior in terms of quantitative accuracy. When the lesion size is small, the MEGP collimator may be favorable. Based on these results, the estimated lower limit of the activity concentration would be approximately 1 kBq/mL if the background concentration is 0.05 kBq/mL for a large lesion.

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Objective: The aim of this study was to evaluate the image quality and the quantification accuracy of Biograph Vision PET/CT scanner as a SiPM-PET in comparison to the conventional PMT-PET, Biograph mCT PET/CT scanner.

Methods: This study consisted of a phantom study and a retrospective clinical analysis where patients underwent 18F-FDG PET/CT in both PET systems. The body phantom of the NEMA IEC with 10-37 mm diameter spheres were filled with an 18F-FDG solution. The root mean square error (RMSE) of SUV, the detectability of 10-mm sphere, NECphantom, the background variability (N10mm) and the contrast-noise-ratio (QH,10 mm/N10mm) were calculated based on the phantom analysis. We also examined the quality of the acquired clinical images using the NECpatient, NECdensity, SNRliver, SUVliver and SUVlesion.

Results: In the phantom study on Vision scanner, RMSE was relatively lower when the iteration number was 2, 3 or 4. To satisfy a visual score of 1.5 and the reference range of QH,10 mm/N10mm, a 60-s or longer acquisition was required. Our clinical findings show that NECpatient averaged 17.4 ± 1.72 Mcounts/m in mCT and 29.1 ± 2.83 Mcounts/m in Vision. Furthermore, NECdensity averaged 0.29 ± 0.05 kcounts/cm3 in mCT and 0.53 ± 0.09 kcounts/cm3 in Vision, respectively, whereas SNRliver averaged 14.6 ± 3.77% in mCT and 21.3 ± 1.69% in Vision (P = 0.0156), respectively. Finally, SUVliver averaged 2.82 ± 0.28 and 2.55 ± 0.30, SUVlesion ranged 1.6-17.6 and 1.9-22.9 in mCT and Vision, respectively.

Conclusion: SiPM-PET/CT provides superior image quality and quantification accuracy compared to PMT-PET/CT.

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Aim: The purpose of this study was to assess the impact of the collimator in viewing the dopamine transporter, using 123I ioflupane single-photon emission computed tomography (DaT-SPECT) images utilizing a Monte Carlo simulation.
Methods: For the purpose of this study, the Monte Carlo simulation of electrons and photons (MCEP)- SPECT was used. A numerical phantom was created from a real basal ganglia phantom and installed within the code. The specific binding ratios (SBRs) were 5.03 and 2.01 for the background concentration of 7.44 kBq/mL or 7.04 and 3.03 for a background concentration of 5.56 kBq/mL. The simulated images were evaluated using a recovery coefficient (RC). Initially, we simulated the performance of 14 collimators without resolution correction to investigate the impact of the collimator dimension. The effects of two resolution correction methods (collimator broad correction (CBC) and three-dimensional frequency– distance relationship (3D-FDR)) on two reconstruction methods (Ordered-Subsets Expectation Maximization (OSEM) and Filtered back projection (FBP)) was assessed for collimators that demonstrated a better RC value.
Results: Five low-energy high-resolution (LEHR) collimators and one medium-energy general-purpose (MEGP) collimator demonstrated superior RC values. These collimators had a high aspect ratio (hole- length/hole-diameter). The maximum RC value without resolution correction was 64.9% when the image was reconstructed with OSEM. The RC value improved to 79.7% when the resolution correction of CBC was applied. When the resolution collection was applied, the RCs improved by approximately 1.2 times when compared against those without the resolution correction. In terms of the reconstruction method, the RC obtained using OSEM was statistically insignificant when compared to the RC using FBP. The difference in the RC value with collimators decreased according to resolution correction.
Conclusion: The LEHR collimator with a high aspect ratio, and the OSEM with spatial resolution correction were confirmed to be appropriate for DaT-SPECT imaging. In terms of the reconstruction method, CBC was more favourable than FDR.

DOI： 10.31487/j.RDI.2019.04.06

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Purpose The purposes of this study were to investigate the correlation between unenhanced CT attenuation values and ¹⁸F-FDG uptake in adrenal adenomas, and to clarify the mechanism of FDG uptake in adrenal adenomas based on immunohistochemical findings. Materials and Methods In 57 adrenal adenomas, the correlation between SUV^max on ¹⁸F-FDG PET and unenhanced CT attenuation was retrospectively investigated. In the 11 surgically resected nodules, the clear cell ratio (CCR) and expression levels of glucose transporters (GLUTs) 1 to 4 were pathologically evaluated. The GLUT expression levels were scored at 0 to 3 points for each transporter, and the sum of these expression levels was defined as the GLUT score. The relationships between CCR and either the CT attenuation number or SUV^max, and between the GLUT score and each of the CT attenutation value, SUV^max, or CCR were evaluated. Results There was a significant positive correlation between SUV^max and the CT attenuation value for the group of 57 adenomas (R = 0.44, P = 0.0007). For the 11 surgically resected cases, there was a nonsignificant trend of negative correlation between SUV^max and CCR (R = 0.57, P = 0.06). There was a significant positive correlation between GLUT score and CT attenuation value (R = 0.68, P = 0.02), and a significant negative correlation between GLUT score and CCR (R = 0.60, P = 0.003). Conclusions Adrenal adenomas composed of many compact cells or having high attenuation on unenhanced CT showed high FDG uptake. FDG uptake of adrenal adenomas may depend on the constituent cells.

DOI： 10.1097/RLU.0000000000002759

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Purpose: To evaluate the clinical outcome of combination of carbon-ion radiotherapy with separation surgery (CIRT-SS) in patients with primary spinal/paraspinal sarcoma (PSPS) and epidural spinal cord compression (ESCC). Methods: CIRT-SS was performed in 11 consecutive patients. Patients treated in the primary and salvage settings were categorized into Group A (n = 8) and Group B (n = 3), respectively. Clinical results and imaging findings were collected, with a particular focus on ESCC grade, treatment-associated adverse events (AEs), and the locoregional control (LRC) rate and overall survival (OS). Results: The median follow-up period from the start of CIRT-SS was 25 months (7–57 months). ESCC was improved by SS in all cases. No patients exhibited radiation-induced myelopathy (RIM), but three developed Grade 3 vertebral compression fracture (VCF) during follow-up. Locoregional recurrences were observed in four patients [Group A: 1 (12.5%), Group B: 3 (100%)]. Over the entire follow-up period, three patients developed distant metastases and two patients died. The 2-year LRC rate and OS were 70% and 80%, respectively. Conclusion: CIRT-SS in the primary setting achieved acceptable LRC and OS without RIM in patients with PSPS and with ESCC. VCF was the most frequent AE associated with CIRT-SS.

DOI： 10.1007/s10147-019-01505-y

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Objective Edge artifacts have been reported on in relation to ¹⁸F-PET using point spread function correction algorithms. The positron range of ⁶⁸Ga is longer than ¹⁸F, and this difference is thought to result in different edge artifacts. The purpose of this study is to clarify the difference in edge artifacts in PET images using point spread function correction in ⁶⁸Ga- and ¹⁸F-PET. Methods We used a National Electrical Manufacturers Association International Electrotechnical Commission body phantom. The phantom was filled severally with ⁶⁸Ga and ¹⁸F solution. The PET data were obtained over a 90 minutes period using a True Point Biograph 16 scanner. The images were then reconstructed with the ordered subset expectation maximization with point spread function correction. The phantom image analyses were performed by a visual assessment of the PET images and profiles, and an absolute recovery coefficient, which was the ratio of the maximum radioactivity of any given hot sphere to its true radioactivity. Results The ring-like edge artifacts of ⁶⁸Ga-PET were less prominent than those in ¹⁸F-PET. The relative radioactivity profiles of ⁶⁸Ga-PET showed low overshoots of the maximum radioactivity although high overshoots did appear in ¹⁸F-PET. The absolute recovery coefficients of ⁶⁸Ga-PET were smaller than those of ¹⁸F-PET. Conclusion The edge artifacts of ⁶⁸Ga-PET were less prominent than those of ¹⁸F-PET, and their overshoots were smaller. The difference in the positron range between ⁶⁸Ga and ¹⁸F may possibly result in the difference in edge artifacts of images reconstructed using the point spread function correction algorithm.

DOI： 10.1097/MNM.0000000000001079

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Objective: Subcommittee on Survey of Nuclear Medicine Practice in Japan has performed a nationwide survey of nuclear medicine practice every 5 years since 1982 to survey contemporary nuclear medicine practice and its changes over the years. Methods: The subcommittee sent questionnaires, including the number and category of examinations as well as the kind and dose of the radiopharmaceuticals during the 30 days of June 2017, to all nuclear medicine institutes. The total numbers for the year 2017 were then estimated. Results: A total of 1132 institutes responded to the survey, including 351 PET centers. The recovery rate was 90.6%. The number of gamma cameras installed was 1332 in total, with 7.0% decrease in 5 years. Dual-head cameras and hybrid SPECT/CT scanners accounted for 88.2 and 23.6%, respectively. The number of single-photon tracer studies in 2017 was 1.08 million which means a decrease in 5.7% in 5 years and 23.6% in 10 years. All but neurotransmitter system, sentinel lymph node, and liver scintigraphy decreased. Bone scintigraphy was a leading examination (32.3%), followed by myocardial scintigraphy (24.1%) and cerebral perfusion study (18.0%) in order. SPECT studies showed an increase from 47.2% to 63.5%. PET centers have also increased from 295 to 389, as compared to the last survey. The 112 PET centers have installed one or two in-house cyclotrons. PET studies showed 24.5% increase in 5 years, with oncology accounting for 88.9%. ¹⁸F-FDG accounted for 98.2% (630,570 examinations). PET examinations using ¹¹C-methionine have decreased, with 2440 examinations in 2017. PET examinations using ¹³N-NH₃ have been increasing, with 2363 examinations in 2017. The number of PET studies using ¹¹C-PIB was 904. ¹³¹I-radioiodine targeted therapies showed an increase in 5 years (23.1%), including 4487 patients for thyroid cancer. Out-patient thyroid bed ablation therapy with 1,110 MBq of ¹³¹I accounted for 36.6% of cancer patients. The number of admission rooms increased from 135 to 157 in 5 years. The number of ²²³Ra targeted therapies for castration-resistant metastatic prostate cancer was 1194 patients. Conclusions: Single-photon examinations showed a continuous tendency toward a decline in the survey. In contrast, the number of hybrid SPECT/CT scanner examinations has increased. PET/CT study and radionuclide targeted therapy have steadily increased.

DOI： 10.1007/s12149-019-01382-5

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Objective: Disturbed sleep due to obstructive sleep apnea syndrome (OSAS) might accelerate amyloidβ (Aβ) deposition, which can be a crucial factor in Alzheimer's disease. We studied Aβ deposition in untreated OSAS patients with normal cognition.

Method: We performed polysomnography (PSG) and Aβ imaging with [11C]-Pittsburgh compound B PET computed tomography (11C-PiB PET CT) in 14 untreated OSAS patients (apnea-hypopnea index: 43.8 ± 26.3/h).

Results: The abnormal accumulation of enhanced 11C-PiB PET was observed only one patient with severe, but not the most severe.

Conclusions: The OSAS severity alone may not predict Aβ deposition in OSAS patients with normal cognition.

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We aimed to evaluate the influence of minimal misalignment of a hot spot on the repeatability of PET images using repositioning of point sources. Methods: Point sources with an inner diameter of 1 mm were made with 1 μL of 18F solution. Seven point sources were placed on the x-axis in the field of view. For fixed-position imaging, PET data were acquired for 10 min 5 times serially. For variable-position imaging, PET data were acquired for 10 min each with the point sources placed at 0, ±0.5, and ±1.0 mm in the x-axis direction. The data were reconstructed using ordered-subsets expectation maximization (OSEM) and OSEM plus point-spread function (PSF). The image matrix was 128 × 128, 200 × 200, 256 × 256, 400 × 400, and 512 × 512 pixels. The normalized maximum count (rMax), the coefficient of variance (CVmax), and the full width at half maximum were analyzed. Results: The hot spots on OSEM images far from the center became faint and broad, whereas those on OSEM+PSF images became small and dense. Although rMax was overestimated at the 5-cm position on OSEM images, rMax at other positions was overestimated on OSEM+PSF images with a matrix of at least 256 × 256. rMax showed a similar pattern in fixed- and variable-position images. CVmax in fixed-position OSEM images was less than 2%, irrespective of matrix size. In contrast, CVmax in variable-position images was higher than in fixed-position images. CVmax was higher for OSEM+PSF images than for OSEM images. The full width at half maximum increased at positions far from the center on OSEM images but was stable at all positions on OSEM+PSF images. Conclusion: The repeatability of the small hot spot was affected by the minimal misalignment, especially on OSEM+PSF images. Precise positioning is necessary if PET is to be used as a biomarker. Professionals should recognize that PSF correction worsens the repeatability of the small hot spot although improving the spatial resolution of PET images.

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

We aimed to evaluate the influence of minimal misalignment of a hot spot on the repeatability of PET images using repositioning of point sources. Methods: Point sources with an inner diameter of 1 mm were made with 1 μL of ¹⁸ F solution. Seven point sources were placed on the x-axis in the field of view. For fixed-position imaging, PET data were acquired for 10 min 5 times serially. For variable-position imaging, PET data were acquired for 10 min each with the point sources placed at 0, ±0.5, and ±1.0 mm in the x-axis direction. The data were reconstructed using ordered-subsets expectation maximization (OSEM) and OSEM plus point-spread function (PSF). The image matrix was 128 x 128, 200 x 200, 256 x 256, 400 x 400, and 512 x 512 pixels. The normalized maximum count (rMax), the coefficient of variance (CV _max ), and the full width at half maximum were analyzed. Results: The hot spots on OSEM images far from the center became faint and broad, whereas those on OSEM1PSF images became small and dense. Although rMax was overestimated at the 5-cm position on OSEM images, rMax at other positions was overestimated on OSEM+PSF images with a matrix of at least 256 x 256. rMax showed a similar pattern in fixed- and variable-position images. CV _max in fixed-position OSEM images was less than 2%, irrespective of matrix size. In contrast, CV _max in variable-position images was higher than in fixed-position images. CV _max was higher for OSEM+PSF images than for OSEM images. The full width at half maximum increased at positions far from the center on OSEM images but was stable at all positions on OSEM+PSF images. Conclusion: The repeatability of the small hot spot was affected by the minimal misalignment, especially on OSEM+PSF images. Precise positioning is necessary if PET is to be used as a biomarker. Professionals should recognize that PSF correction worsens the repeatability of the small hot spot although improving the spatial resolution of PET images.

DOI： 10.2967/jnmt.118.208835

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Objective: Disturbed sleep due to obstructive sleep apnea syndrome (OSAS) might accelerate amyloidβ (Aβ) deposition, which can be a crucial factor in Alzheimer’s disease. We studied Aβ deposition in untreated OSAS patients with normal cognition. Method: We performed polysomnography (PSG) and Aβ imaging with [
¹¹
C]-Pittsburgh compound B PET computed tomography (
¹¹
C-PiB PET CT) in 14 untreated OSAS patients (apnea–hypopnea index: 43.8 ± 26.3/h). Results: The abnormal accumulation of enhanced
¹¹
C-PiB PET was observed only one patient with severe, but not the most severe. Conclusions: The OSAS severity alone may not predict Aβ deposition in OSAS patients with normal cognition.

DOI： 10.1007/s12149-019-01349-6

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Objective: Radium-223 (223Ra) is used in unsealed radionuclide therapy for metastatic bone tumors. The aim of this study is to apply a computational model observer to 223Ra planar images, and to assess the performance of collimators in 223Ra imaging.

Methods: The 223Ra planar images were created via an in-house Monte Carlo simulation code using HEXAGON and NAI modules. The phantom was a National Electrical Manufacturers Association body phantom with a hot sphere. The concentration of the background was 55 Bq/mL, and the sphere was approximately 1.5-20 times that of the background concentration. The acquisition time was 10 min. The photopeaks (and the energy window) were 84 (full width of energy window: 20%), 154 (15%), and 270 keV (10%). Each 40 images, with and without hot concentration, were applied to a three-channel difference-of-Gaussian channelized Hotelling observer (CHO), and the signal-to-noise ratio (SNR) of the hot region was calculated. The images were examined using five different collimators: two low-energy general-purpose (LEGP), two medium-energy general-purpose (MEGP), and one high-energy general-purpose (HEGP) collimators.

Results: The SNR value was linearly proportional to the contrast of the hot region for all collimators and energy windows. The images of the 84-keV energy window with the MEGP collimator that have thicker septa and larger holes produced the highest SNR value. The SNR values of two LEGP collimators were approximately half of the MEGP collimators. The HEGP collimator was halfway between the MEGP and LEGP. Similar characteristics were observed for other energy windows (154, 270 keV). The SNR value of images captured via the 270-keV energy window was larger than 154-keV, although the sensitivity of the 270-keV energy window is lower than 154-keV. The results suggested a positive correlation between the SNR value and the fraction of unscattered photons.

Conclusions: The SNR value of CHO reflected the performance of collimators and was available to assess and quantitatively evaluate the collimator performance in 223Ra imaging. The SNR value depends on the magnitudes of unscattered photon count and the fraction of unscattered photon count. Consequently, in this study, MEGP collimators performed better than LEGP and HEGP collimators for 223Ra imaging.

DOI： 10.1007/s12149-018-1286-4

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Background: To evaluate the prognostic outcome and surgical complications in patients with early-stage cervical cancer who underwent sentinel node navigation surgery (SNNS) for hysterectomy or trachelectomy. Methods: A total of 139 patients who underwent SNNS using ^99mTc phytate between 2009 and 2015 were evaluated. No further lymph node dissection was performed when intraoperative analysis of the sentinel lymph nodes (SLNs) was negative for metastasis. We compared the surgical complications between the SNNS group and 67 matched patients who underwent pelvic lymph node dissection (PLND) after SLN mapping between 2003 and 2008. We also examined the clinical outcomes in the SNNS group. Results: The mean number of detected SLNs was 2.5 per patient. Fourteen of the 139 patients in the SNNS group underwent PLND based on the intraoperative SLN results. The amount of blood loss, the operative time, and the number of perioperative complications were significantly less in the SNNS group than in the matched PLND group. There was no recurrence during a follow-up period ranging from 2 to 88 months (median 40 months) in the SNNS group. Conclusions: Using SNNS for early-stage cervical cancer is safe and effective and does not increase the recurrence rate. A future multicenter trial is warranted.

DOI： 10.1007/s10147-018-1327-y

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Objectives: The aim of this study is to examine the effect of different smoothing filters on the image quality and SUVmax to achieve the guideline recommended positron emission tomography (PET) image without harmonization.
Methods: We used a Biograph mCT PET scanner. A National Electrical Manufacturers Association (NEMA) the International Electrotechnical Commission (IEC) body phantom was filled with 18F solution with a background activity of 2.65 kBq/mL and a sphere-to-background ratio of 4. PET images obtained with the Biograph mCT PET scanner were reconstructed using the ordered subsets-expectation maximization (OSEM) algorithm with time-of-flight (TOF) models (iteration, 2; subset, 21); smoothing filters including the Gaussian, Butterworth, Hamming, Hann, Parzen, and Shepp-Logan filters with various full width at half maximum (FWHM) values (1-15 mm) were applied. The image quality was physically assessed according to the percent contrast (QH,10), background variability (N10), standardized uptake value (SUV), and recovery coefficient (RC). The results were compared with the guideline recommended range proposed by the Japanese Society of Nuclear Medicine and the Japanese Society of Nuclear Medicine Technology. The PET digital phantom was developed from the digital reference object (DRO) of the NEMA IEC body phantom smoothed using a Gaussian filter with a 10-mm FWHM and defined as the reference image. The difference in the SUV between the PET image and the reference image was evaluated according to the root mean squared error (RMSE).
Results: The FWHMs of the Gaussian, Butterworth, Hamming, Hann, Parzen, and Shepp-Logan filters that satisfied the image quality of the FDG-PET/CT standardization guideline criteria were 8-12 mm, 9-11 mm, 9-13 mm, 10-13 mm, 9-11 mm, and 12-15 mm, respectively. The FWHMs of the Gaussian, Butterworth, Hamming, Hann, Parzen, and Shepp-Logan filters that provided the smallest RMSE between the PET images and the 3D digital phantom were 7 mm, 8 mm, 8 mm, 8 mm, 7 mm, and 11 mm, respectively.
Conclusion: The suitable FWHM for image quality or SUVmax depends on the type of smoothing filter that is applied.

DOI： 10.22038/aojnmb.2017.26684.1186

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

Recent advancements in clinical PET/CT scanners have improved the detectability of small lesions. However, the ideal reconstruction parameters for detecting small lesions have not yet been sufficiently clarified. The purpose of this study was to investigate the detectability of subcentimeter spheres using a clinical PET/CT scanner. Methods: We used a clinical PET/CT scanner to obtain the data of a National Electrical Manufacturers Association body phantom consisting of 6 small spheres (inner diameters, 4.0, 5.0, 6.2, 7.9, 10, and 37 mm) containing ¹⁸F solution. The background activity was 2.65 kBq/mL, and the sphere-to-background ratio was 8. The PET data obtained for 2 and 120 min were reconstructed using ordered-subsets expectation maximization (OSEM), OSEM 1 point-spread function (PSF), and OSEM 1 time-of-flight (TOF) with voxel sizes of 2.04 × 2.04 × 2.00 mm (2-mm voxels) and 4.07 × 4.07 × 3.99 mm (4-mm voxels). A gaussian filter was not used. The image quality was evaluated by visual assessment, as well as by physical assessment of the detectability index and recovery coefficients. Results: According to the visual assessment, the detectability of the spheres improved using TOF and a longer acquisition. Using the OSEM1TOF model, the smallest visually detected spheres were 5 mm in diameter with a 120-min acquisition and 6 mm in diameter with a 2-min acquisition. According to physical assessment, the detectability of spheres 10 mm or smaller using the OSEM1TOF image was superior to that using the OSEM image. In addition, the detectability of each hot sphere and recovery coefficient with 2-mm voxels was superior to that with 4-mm voxels. Although OSEM1PSF images showed less background noise, detectability and the recovery coefficient were not improved for spheres 8 mm or smaller. Conclusion: The TOF model with 2-mm voxels improved the detectability of subcentimeter hot spheres on a clinical PET/CT scanner.

DOI： 10.2967/jnmt.117.204735

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

Background and Objectives: Trachelectomy, a fertility-sparing surgery for early-stage cervical cancer, can be performed only when there is no extrauterine extension present. Therefore, identifying the sentinel lymph nodes (SLNs) and using them to obtain an intraoperative pathologic diagnosis can provide information on the feasibility and safety of trachelectomy. Our aim was to assess the value of an intraoperative SLN diagnosis. Methods: We retrospectively analyzed the accuracy of intraoperative imprint cytology and frozen-section examination in 201 patients at our institution in whom trachelectomy was planned. Results: All patients could be evaluated for SLNs; a total of 610 SLNs were analyzed. Although the specificity of both imprint cytology and frozen-section examination was 100.0%, the sensitivity was only 58.6 and 65.5%, respectively. The diagnostic sensitivity was higher in 2-mm slices along the short axis than on bisection along the longitudinal axis. Imprint cytology correctly diagnosed 2 patients who had false-negative results on frozen section. The nature of the metastatic foci that caused an intraoperative false-negative diagnosis was either micrometastasis or isolated tumor cells. Conclusions: The accuracy of intraoperative SLN diagnosis requires improvement, especially when small metastatic foci are present.

DOI： 10.1159/000484049

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

This trial enrolls patients with untreated Hodgkin's lymphoma aged<20 years at diagnosis and examines the effects of omitting radiation therapy if the FDG-positron emission tomography (PET) findings after two completed cycles of combination chemotherapy are negative. It thereby aims to determine whether patients who truly require radiation therapy can be identified by FDG-PET. If so, this modality could be used to omit radiation therapy for all other patients, decreasing the risk of serious long-term complications without affecting survival rates. The outcomes of patients for whom FDG-PET is used to assess early treatment response will also be determined.

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

Objectives: Yttrium-90 (90Y) is a beta particle nuclide used in targeted radionuclide therapy which is available to both single-photon emission computed tomography (SPECT) and time-of-flight (TOF) positron emission tomography (PET) imaging. The purpose of this study was to assess the image quality of PET and Bremsstrahlung SPECT by simulating PET and SPECT images of 90Y using Monte Carlo simulation codes under the same conditions and to compare them.
Methods: In-house Monte Carlo codes, MCEP-PET and MCEP-SPECT, were employed to simulate images. The phantom was a torso-shaped phantom containing six hot spheres of various sizes. The background concentrations of 90Y were set to 50, 100, 150, and 200 kBq/mL, and the concentrations of the hot spheres were 10, 20, and 40 times of those of the background concentrations. The acquisition time was set to 30 min, and the simulated sinogram data were reconstructed using the ordered subset expectation maximization method. The contrast recovery coefficient (CRC) and contrast-to-noise ratio (CNR) were employed to evaluate the image qualities.
Results: The CRC values of SPECT images were less than 40%, while those of PET images were more than 40% when the hot sphere was larger than 20 mm in diameter. The CNR values of PET images of hot spheres of diameter smaller than 20 mm were larger than those of SPECT images. The CNR values mostly exceeded 4, which is a criterion to evaluate the discernibility of hot areas. In the case of SPECT, hot spheres of diameter smaller than 20 mm were not discernable. On the contrary, the CNR values of PET images decreased to the level of SPECT, in the case of low concentration.
Conclusion: In almost all the cases examined in this investigation, the quantitative indexes of TOF-PET 90Y images were better than those of Bremsstrahlung SPECT images. However, the superiority of PET image became critical in the case of low activity concentrations.

DOI： 10.22038/aojnmb.2017.9673

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

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

DOI： 10.1007/s00330-017-4941-6

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

Programmed cell death-1 (PD-1) and programmed cell death-ligand 1 (PD-L1) have been identified as novel targets of immunotherapy of lung cancer. In present study, we evaluated the metabolic characteristics of lung cancer by using ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) with regard to PD-L1 protein expression. PD-L1 protein expression was evaluated by immunohistochemistry with the antibody clone SP142 in 579 surgically resected primary lung cancer patients. Cases with less than 5% tumor membrane staining were considered negative. We examined the association between the frequency of PD-L1 protein expression and the maximum standardized uptake value (SUVmax) in preoperative ¹⁸F-FDG PET/CT. The cut-off values for SUVmax were determined by receiver operating characteristic curve analyses. The SUVmax was significantly higher in nonsmall cell lung cancer (NSCLC) patients with PD-L1 protein expression compared with those without PD-L1 protein expression (P < 0.0001). However, there was no correlation between SUVmax and PD-L1 protein expression in patients with neuroendocrine tumors (P = 0.6545). Multivariate analysis revealed that smoking, the presence of pleural invasion, and high SUVmax were independent predictors of PD-L1 positivity. PD-L1-expressing NSCLC had a high glucose metabolism. The SUVmax in preoperative ¹⁸F-FDG PET/CT was a predictor of PD-L1 protein expression in patients with NSCLC.

DOI： 10.1002/cam4.1215

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

BACKGROUND: It is difficult to detect bone defects caused by loosening or osteolysis around the femoral component after total knee arthroplasty (TKA) because the thick metal hinders visualization of bone defects. Previous reports have shown that tomosynthesis, a novel tomographic technique, is advantageous over fluoroscopically guided plain radiography, computed tomography (CT) and magnetic resonance imaging (MRI) for the early detection of bone defects around a conventional cobalt-chromium alloy component. However, there have been no reports on a zirconium component. The purpose of this study was to examine the sensitivity and specificity of the detection of bone defects around a zirconium component using fluoroscopically guided plain radiography, tomosynthesis, CT and MRI.
METHODS: Six zirconium femoral components were implanted in pig knees. Two were cemented without any bone defects. Two were cemented with cystic defects. Two were cemented with four-millimeter-thick defects between the bone cement and the bone. Defects were filled with agarose gel. Eight orthopedic surgeons examined the fluoroscopically guided plain radiography, tomosynthesis, CT and MRI images. Sensitivity and specificity of each method were analyzed.
RESULTS: No bone defects were detected with plain radiography. The sensitivity and specificity of tomosynthesis were 21.9% and 36.8%, respectively. The sensitivity and specificity of CT were 15.1% and 33.0%, respectively. The sensitivity and specificity of MRI were 84.4% and 86.6%, respectively.
CONCLUSIONS: For the detection of bone defects around a zirconium component after TKA, MRI is advantageous over fluoroscopically guided plain radiography, tomography and CT, in terms of sensitivity and specificity.

DOI： 10.1016/j.knee.2017.04.020

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

The distribution of activation inside a compact medical cyclotron was evaluated by measuring 1 cm dose equivalent rates and γ-ray spectra. Analysis of the distribution of activation showed high activation at the deflector and the magnetic channel. Radionuclides ⁶⁰Co, ⁵⁷Co, ⁶⁵Zn, and ⁵⁴Mn were detected. Different radionuclides were generated from different components of the cyclotron, and low-activity radionuclides could be detected under low-background-radiation conditions.

DOI： 10.1016/j.apradiso.2017.02.045

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

Background Programmed death ligand 1 (PD-L1) was reported to predict the response of immunotherapy; however, the association between PD-L1 expression and radiologic and pathologic features has yet to be elucidated. Methods In all, 292 patients with resected pathologic stage I adenocarcinoma were analyzed for PD-L1 expression by immunohistochemistry and evaluated to determine the association between PD-L1 expression and the radiologic/pathologic invasiveness. Specifically, the radiologic invasiveness and noninvasiveness were determined based on the consolidation/tumor ratio, with a cutoff value of 0.25 by thin-section computed tomography. Results Among 292 patients, 47 (16.1%) were positive for PD-L1 expression; the remaining 245 patients (83.9%) were negative for PD-L1 expression. Fisher's exact test demonstrated that PD-L1 expression was significantly associated with a higher consolidation/tumor ratio (p = 0.029) and higher maximum standardized uptake value (p = 0.004). The mean values of consolidation/tumor ratio and maximum standardized uptake in patients with and without PD-L1 expression were 0.845 ± 0.052 and 7.241 ± 0.795, and 0.607 ± 0.023 and 3.60 ± 0.364, respectively (p < 0.001 and p < 0.001, respectively). Among 47 adenocarcinomas harboring PD-L1 expression, the frequencies of PD-L1 expression for consolidation/tumor ratios of 0, 0.1 to 0.25, 0.26 to 0.5, and 0.51 or more were 6.4%, 2.1%, 4.3%, and 87.2%, respectively (p = 0.007). Pathologically, PD-L1 was identified exclusively only in more invasive subtypes, not in less invasive ones, such as atypical adenomatous hyperplasia, adenocarcinoma in situ, minimally invasive adenocarcinoma, and lepidic predominant ones (p < 0.001). Conclusions Expression of PD-L1 was significantly associated with radiologic/pathologic invasive adenocarcinomas. This study provides the first evidence of the radiologic and pathologic invasiveness in resected pathologic stage I adenocarcinoma with PD-L1 expression.

DOI： 10.1016/j.athoracsur.2016.12.025

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

Objective Balloon pulmonary angioplasty (BPA) is used for inoperable chronic thromboembolic pulmonary hypertension (CTEPH), but its effect cannot be evaluated noninvasively. We devised a noninvasive quantitative index of response to BPA using three-dimensional fractal analysis (3D-FA) of technetium-99m-macroaggregated albumin (99m Tc-MAA) single-photon emission computed tomography (SPECT). Patients and methods Forty CTEPH patients who underwent pulmonary perfusion scintigraphy and mean pulmonary arterial pressure (mPAP) measurement by right heart catheterization before and after BPA were studied. The total uptake volume (TUV) in bilateral lungs was determined from maximum intensity projection 99m Tc-MAA SPECT images. Fractal dimension was assessed by 3D-FA. Parameters were compared before and after BPA, and between patients with post-BPA mPAP more than 30 mmHg and less than or equal to 30 mmHg. Receiver operating characteristic analysis was carried out. Results BPA significantly improved TUV (595±204-885±214 ml, P<0.001) and reduced the laterality of uptake (238±147-135±131 ml, P<0.001). Patients with poor therapeutic response (post-BPA mPAP≥30 mmHg, n=16) showed a significantly smaller TUV increase (P=0.044) and a significantly greater post-BPA fractal dimension (P<0.001) than the low-mPAP group. Fractal dimension correlated with mPAP values before and after BPA (P=0.013 and 0.001, respectively). A post-BPA fractal dimension threshold of 2.4 distinguished between BPA success and failure with 75% sensitivity, 79% specificity, 78% accuracy, and area under the curve of 0.85. Conclusion 3D-FA using 99m Tc-MAA SPECT pulmonary perfusion scintigraphy enables a noninvasive evaluation of the response of CTEPH patients to BPA.

DOI： 10.1097/MNM.0000000000000673

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

BACKGROUND AND PURPOSE: Primary malignant spine/spinal tumors (PMSTs) are rare and life-threatening diseases. In this study, we demonstrated the advantage of volume-based (18)F-FDG PET/CT metabolic parameter, metabolic tumor volume (MTV), for assessing the aggressiveness of PMSTs.
MATERIALS AND METHODS: We retrospectively reviewed 27 patients with PMSTs and calculated SUVmax, MTV, and total lesion glycolysis (TLG) to compare their accuracy in predicting progression-free survival (PFS) and overall survival (OS) by receiver operating characteristic (ROC) curve analysis. Univariate and multivariate analyses were used to compare the reliability of the metabolic parameters and various clinical factors.
RESULTS: MTV exhibited greater accuracy than SUVmax or TLG. The cut-off values for PFS and OS derived from the AUC data were MTV 45 ml and 83 ml and TLG 250 SUV⁎ml and 257 SUV⁎ml, respectively. MTV above cut-off value, but not TLG, was identified as significant prognostic factor for PFS by log-lank test (p = 0.04). In addition, MTV was the only significant predictive factors for PFS and OS in the multivariate analysis.
CONCLUSIONS: MTV was a more accurate predictor of PFS and OS in PMSTs compared to TLG or SUVmax and helped decision-making for guiding rational treatment options.

DOI： 10.1155/2017/8132676

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

OBJECTIVES: We evaluated edge artifacts in relation to phantom diameter and reconstruction parameters in point spread function (PSF)-based positron emission tomography (PET) image reconstruction.
METHODS: PET data were acquired from an original cone-shaped phantom filled with 18F solution (21.9 kBq/mL) for 10 min using a Biograph mCT scanner. The images were reconstructed using the baseline ordered subsets expectation maximization (OSEM) algorithm and the OSEM with PSF correction model. The reconstruction parameters included a pixel size of 1.0, 2.0, or 3.0 mm, 1-12 iterations, 24 subsets, and a full width at half maximum (FWHM) of the post-filter Gaussian filter of 1.0, 2.0, or 3.0 mm. We compared both the maximum recovery coefficient (RCmax) and the mean recovery coefficient (RCmean) in the phantom at different diameters.
RESULTS: The OSEM images had no edge artifacts, but the OSEM with PSF images had a dense edge delineating the hot phantom at diameters 10 mm or more and a dense spot at the center at diameters of 8 mm or less. The dense edge was clearly observed on images with a small pixel size, a Gaussian filter with a small FWHM, and a high number of iterations. At a phantom diameter of 6-7 mm, the RCmax for the OSEM and OSEM with PSF images was 60% and 140%, respectively (pixel size: 1.0 mm; FWHM of the Gaussian filter: 2.0 mm; iterations: 2). The RCmean of the OSEM with PSF images did not exceed 100%.
CONCLUSION: PSF-based image reconstruction resulted in edge artifacts, the degree of which depends on the pixel size, number of iterations, FWHM of the Gaussian filter, and object size.

DOI： 10.22038/aojnmb.2017.8802

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

Objective: ⁹⁰Y-ibritumomab tiuxetan (Zevalin) which is used for the treatment of malignant lymphomas can be used for SPECT imaging based on bremsstrahlung from ⁹⁰Y beta particles. However, gamma rays emitted by ¹¹¹In, which is administered to evaluate the indication for the treatment, contaminate the ⁹⁰Y bremsstrahlung images. Our objective is to investigate the influence of ¹¹¹In on the ⁹⁰Y SPECT images using Monte Carlo simulation. Methods: We used an in-house developed simulation code for the Monte Carlo simulation of electrons and photons (MCEP). Two hot spheres with diameters of 40 mm were put in an elliptical phantom. Both spheres (“sphere 1” and “sphere 2”) were filled with ⁹⁰Y and ¹¹¹In mixed solutions. The activities of ⁹⁰Y in sphere 1 and sphere 2 were 241 and 394 kBq/mL, respectively, and the ones of ¹¹¹In were 8.14 and 13.3 kBq/mL, respectively. The background activity of ⁹⁰Y was 38.6 kBq/mL, whereas that of ¹¹¹In was 1.30 kBq/mL; moreover, the acquisition time was 30 min. Two energy windows were used: one is 90–190 keV included the ¹¹¹In photopeak; the other is 90–160 keV. To evaluate the quality of the SPECT images, the contrast recovery coefficient (CRC) and the constant noise ratio (CNR) of the SPECT images were derived. Results: For the energy window between 90 and 160 keV, the ¹¹¹In count was 74 % of the total. In that case, the CRC values were 30.1 and 30.7 % for “sphere 1” and “sphere 2”, respectively, whereas the CNR values were 6.8 and 12.1, respectively. For the energy window between 90 and 190 keV, the ¹¹¹In count reached 85 % of the total count. The CRC and CNR values were 38.6 and 40.0 % and 10.6 and 19.4, respectively. Conclusions: Our simulation study revealed that the cross talk between ¹¹¹In and ⁹⁰Y in SPECT imaging is rather serious. Even for the energy window excluding the ¹¹¹In photopeak, the count ratio of ⁹⁰Y was less than 30 % of the total. However, the influence of ¹¹¹In on ⁹⁰Y-SPECT imaging cannot be ignored, and the count ratio because of ¹¹¹In is important to estimate the density of ⁹⁰Y.

DOI： 10.1007/s12149-016-1112-9

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：Japanese   Publishing type：Research paper (scientific journal)  

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

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

Objective: The purpose of this study was to investigate the influence of respiratory motion on the evaluation of the intratumoral heterogeneity of FDG uptake using cumulative SUV-volume histogram (CSH) and fractal analyses. Methods: We used an NEMA IEC body phantom with a homogeneous hot sphere phantom (HO) and two heterogeneous hot sphere phantoms (HE1 and HE2). The background radioactivity of ¹⁸F in the NEMA phantom was 5.3 kBq/mL. The ratio of radioactivity was 4:2:1 for the HO and the outer rims of the HE1 and HE2 phantoms, the inner cores of the HE1 and HE2 phantoms, and background, respectively. Respiratory motion was simulated using a motion table with an amplitude of 2 cm. PET/CT data were acquired using Biograph mCT in motionless and moving conditions. The PET images were analyzed by both CSH and fractal analyses. The area under the CSH (AUC-CSH) and the fractal dimension (FD) was used as quantitative metrics. Results: In motionless conditions, the AUC-CSHs of the HO (0.80), HE1 (0.75) and HE2 (0.65) phantoms were different. They did not differ in moving conditions (HO, 0.63; HE1, 0.65; HE2, 0.60). The FD of the HO phantom (0.77) was smaller than the FDs of the HE1 (1.71) and HE2 (1.98) phantoms in motionless conditions; however, the FDs of the HO (1.99) and HE1 (2.19) phantoms were not different from each other and were smaller than that of the HE2 (3.73) phantom in moving conditions. Conclusion: Respiratory motion affected the results of the CSH and fractal analyses for the evaluation of the heterogeneity of the PET/CT images. The influence of respiratory motion was considered to vary depending on the object size.

DOI： 10.1007/s12149-016-1071-1

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

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

Purpose: Radium-223 (²²³Ra), an α-emitting radionuclide, is used in unsealed radionuclide therapy for metastatic bone tumors. The demand for qualitative ²²³Ra imaging is growing to optimize dosimetry. The authors simulated ²²³Ra imaging using an in-house Monte Carlo simulation code and investigated the feasibility and utility of ²²³Ra imaging. Methods: The Monte Carlo code comprises two modules, HEXAGON and NAI. The HEXAGON code simulates the photon and electron interactions in the tissues and collimator, and the NAI code simulates the response of the NaI detector system. A 3D numeric phantom created using computed tomography images of a chest phantom was installed in the HEXAGON code. ²²³Ra accumulated in a part of the spine, and three x-rays and 19 γ rays between 80 and 450 keV were selected as the emitted photons. To evaluate the quality of the ²²³Ra imaging, the authors also simulated technetium-99m (^99mTc) imaging under the same conditions and compared the results. Results: The sensitivities of the three photopeaks were 147 counts per unit of source activity (cps MBq^-1; photopeak: 84 keV, full width of energy window: 20%), 166 cps MBq^-1 (154 keV, 15%), and 158 cps MBq^-1 (270 keV, 10%) for a low-energy general-purpose (LEGP) collimator, and those for the medium-energy general-purpose (MEGP) collimator were 33, 13, and 8.0 cps MBq^-1, respectively. In the case of ^99mTc, the sensitivity was 55 cps MBq^-1 (141 keV, 20%) for LEGP and 52 cps MBq^-1 for MEGP. The fractions of unscattered photons of the total photons reflecting the image quality were 0.09 (84 keV), 0.03 (154 keV), and 0.02 (270 keV) for the LEGP collimator and 0.41, 0.25, and 0.50 for the MEGP collimator, respectively. Conversely, this fraction was approximately 0.65 for the simulated ^99mTc imaging. The sensitivity with the LEGP collimator appeared very high. However, almost all of the counts were because of photons that penetrated or were scattered in the collimator; therefore, the proportions of unscattered photons were small. Conclusions: Their simulation study revealed that the most promising scheme for ²²³Ra imaging is an 84-keV window using an MEGP collimator. The sensitivity of the photopeaks above 100 keV is too low for ²²³Ra imaging. A comparison of the fractions of unscattered photons reveals that the sensitivity and image quality are approximately two-thirds of those for ^99mTc imaging.

DOI： 10.1118/1.4948682

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

Objectives Anatomical coronary stenosis is not always indicative of functional stenosis, particularly for intermediate coronary lesions. The purpose of this study is to propose a new method for quantifying coronary flow using dynamic CT angiography for the whole heart (heart-DCT) and investigate its ability for detecting ischemia from intermediate coronary stenosis. Methods Participants comprised 36 patients with coronary artery disease who underwent heart-DCT using 320-detector CT with tube voltage of 80 kV and myocardial perfusion scintigraphy (MPS). Heart-DCT was continuously performed at mid-diastole throughout 15-25 cardiac cycles with prospective ECG-gating after bolus injection of contrast media (12-24 ml). Dynamic datasets were computed into 90-100 data sets by motion coherence image processing (MCIP). Next, time-density curves (TDCs) for coronary arteries with a diameter >3 mm were automatically calculated for all phases using MCIP. On the basis of the maximum slope method, coronary flow index (CFI) was defined as the ratio of the maximum upslope of coronary artery attenuation to the upslope of ascending aorta attenuation on the TDC, and was used to quantify coronary flow. CFIs for the proximal and distal sites of coronary arteries with mild-to-moderate stenosis were calculated. Coronary territories were categorized as non-ischemic or ischemic by MPS. Receiver-operating-characteristic (ROC) analysis was performed to determine the optimal cutoff for CFI to detect ischemia. Results Distal CFI was significantly lower for ischemia (0.26 ± 0.08) than for non-ischemia (0.50 ± 0.17, p < 0.0001). No significant difference in proximal CFI was seen between ischemia (0.55 ± 0.23) and non-ischemia (0.62 ± 0.24). ROC analysis revealed 0.39 as the optimal cutoff for distal CFI to detect ischemia, with C-statistics of 0.91, 100% sensitivity, and 75% specificity. Conclusions This novel imaging technique allows coronary flow quantification using heart-DCT. Distal CFI can detect myocardial ischemia derived from intermediate coronary stenosis.

DOI： 10.1016/j.ejrad.2016.02.027

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

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

Purpose To compare zoomed diffusion-weighted imaging (z-DWI) with reduced field of view (FOV) by spatially selective radiofrequency pulses and conventional echo planar imaging (EPI) DWI (c-DWI) with regard to registration quality using positron emission tomography / magnetic resonance (PET/MR) in patients with malignant tumors. Materials and Methods Fludeoxyglucose (18^F) PET imaging, c-DWI, and z-DWI were conducted simultaneously in 21 patients with known or suspected malignancy using a PET/MR system. A fusion image showing the largest tumor area was generated for analysis. Registration accuracy between PET and DWI was assessed based on the area of maximum overlap and central point displacement of the tumor. EPI factor, echo time (TE), matching area, and displacement were compared between c-DWI and z-DWI by paired t-test. Agreement of apparent diffusion coefficient (ADC) acquired by the two sequences were also assessed with linear regression s and Bland-Altman plot analysis. Results Thirty-two lesions were detected on both PET and DWI (mean size 536.3 ± 471.8 mm²). At least one lesion was found in all subjects. In all cases, EPI factor was smaller with z-DWI than c-DWI (43.1 ± 15.6 vs. 62.0 ± 10.0, P < 0.0001), and TE was also shorter for z-DWI (53.6 ± 3.6 msec vs. 65.2 ± 3.6 msec, P < 0.0001). Registration accuracy was better with z-DWI in 30 of 32 lesions (93.8%), and both average matching area and central point displacement were significantly improved (79.8 ± 18.1% vs. 61.8 ± 22.9%, P < 0.0001 and 3.92 ± 2.69 mm vs. 7.51 ± 4.07 mm, P < 0.0001). ADC values calculated with c-DWI and z-DWI showed good agreement. Conclusion Zoomed DWI reduces image distortion and provides better registration accuracy with PET images.

DOI： 10.1002/jmri.25059

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

The aim of this study was to investigate the effects of MR parameters on tissue segmentation and determine the optimal MR sequence for attenuation correction in PET/MR hybrid imaging. Eight healthy volunteers were examined using a PET/MR hybrid scanner with six three-dimensional turbo-field-echo sequences for attenuation correction by modifying the echo time, k-space trajectory in the phase-encoding direction, and image contrast. MR images for attenuation correction were obtained from six MR sequences in each session; each volunteer underwent four sessions. Two radiologists assessed the attenuation correction maps generated from the MR images with respect to segmentation errors and ghost artifacts on a five-point scale, and the scores were decided by consensus. Segmentation accuracy and reproducibility were compared. Multiple regression analysis was performed to determine the effects of each MR parameter. The two three-dimensional turbo-field-echo sequences with an in-phase echo time and radial k-space sampling showed the highest total scores for segmentation accuracy, with a high reproducibility. In multiple regression analysis, the score with the shortest echo time (-3.44, P < 0.0001) and Cartesian sampling in the anterior/posterior phase-encoding direction (-2.72, P = 0.002) was significantly lower than that with in-phase echo time and Cartesian sampling in the right/left phase-encoding direction. Radial k-space sampling provided a significantly higher score (+. 5.08, P < 0.0001) compared with Cartesian sampling. Furthermore, radial sampling improved intrasubject variations in the segmentation score (-8.28%, P = 0.002). Image contrast had no significant effect on the total score or reproducibility. These results suggest that three-dimensional turbo-field-echo MR sequences with an in-phase echo time and radial k-space sampling provide improved MR-based attenuation correction maps.

DOI： 10.1016/j.mri.2015.10.037

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

The non-self-shield compact medical cyclotron and the cyclotron vault room were in operation for 27 years. They have now been decommissioned. We efficiently implemented a technique to identify an activation product in the cyclotron vault room. Firstly, the distribution of radioactive concentrations in the concrete of the cyclotron vault room was estimated by calculation from the record of the cyclotron operation. Secondly, the comparison of calculated results with an actual measurement was performed using a NaI scintillation survey meter and a high-purity germanium detector. The calculated values were overestimated as compared to the values measured using the NaI scintillation survey meter and the high-purity germanium detector. However, it could limit the decontamination area. By simulating the activation range, we were able to minimize the concrete core sampling. Finally, the appropriate range of radioactivated area in the cyclotron vault room was decontaminated based on the results of the calculation. After decontamination, the radioactive concentration was below the detection limit value in all areas inside the cyclotron vault room. By these procedures, the decommissioning process of the cyclotron vault room was more efficiently performed.

DOI： 10.6009/jjrt.2016_JSRT_72.10.989

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Objective: The aim of this study was to investigate the relationship between the NEC and TOF-PET image quality. Methods: The National Electrical Manufactures Association and International Electrical Commission (NEMA IEC) body phantom with a 10-mm diameter sphere was filled with an ¹⁸F-FDG solution with a 4:1 radioactivity ratio. The PET data were acquired in the three-dimensional list mode for 20 min. We created frame data ranging from 1 to 5 min acquisition time, which were then reconstructed using the baseline ordered-subsets expectation maximization (OSEM), the OSEM + point spread function (PSF) algorithm, OSEM + time-of-flight (TOF) algorithm and OSEM + PSF + TOF algorithm. The PET images were analyzed according to the noise-equivalent count (NEC), the coefficients of variance of the background (CV_BG), the maximum count (CV_max) and the contrast (CV_CONT). The results were compared with the recommended value according to the guidelines for the oncology FDG-PET/CT protocol. Results: The NEC was higher than the recommended value at 3 min or longer acquisition time. The CV_BG lower than 15 % were obtained at 3 min acquisition time without TOF and at 2 min acquisition time with TOF. The CV_BG of 10 % or lower were obtained at 5 min or longer acquisition time without TOF and at 4 min or longer acquisition time with TOF. Both the CV_max and CV_CONT lower than 10 % were obtained at 3 min or longer acquisition time without TOF and at 1 min acquisition or longer with TOF. No particular relationships were observed between the frame number and degree of the variation in the image quality. The CV_CONT significantly correlated with the NEC for the data reconstructed without TOF information, while there were no significant correlations between these useful metrics for the data reconstructed with TOF. Conclusion: This study demonstrated that the NEC is not a useful metric for the evaluation of the image quality on TOF-PET images.

DOI： 10.1007/s12149-015-1032-0

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Aim To find significant parameters to characterise anterior mediastinal solid tumours in adults using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), diffusion-weighted MRI (DWI), and combined 2-[¹⁸F]-fluoro-2-deoxy-d-glucose positron-emission tomography/computed tomography (FDG-PET/CT). Materials and methods Forty-eight histologically confirmed anterior mediastinal solid tumours in 48 patients (24 men, 24 women; age range 21-83 years, mean 50.7 years) were examined. The parameters analysed were maximal diameter, presence of capsule/septa on T2-weighted images, time-signal intensity curves (TICs), apparent diffusion coefficient (ADC), and maximum standardised uptake value (SUV_max). Also examined was whether any differences between histological types could be seen in these parameters. In a validation study, 42 anterior mediastinal solid tumours in 42 patients were examined consecutively. Results The washout pattern on TIC was seen only in thymic epithelial tumours (20/32). SUV_max of lymphoma (mean, 17.9), malignant germ cell tumours (14.2), and thymic carcinomas (15.6) were significantly higher than that of thymomas (6.1). The mean maximal diameter of thymic epithelial tumours was significantly smaller than that of lymphomas (p<0.01) and malignant germ cell tumours (p<0.05). The validation study also yielded high accuracy (38/42, 91%) in differentiation among the anterior mediastinal solid tumours. Conclusion The SUV_max, TIC pattern on DCE-MRI, and maximal diameter might be useful to differentiate anterior mediastinal solid tumours in adults.

DOI： 10.1016/j.crad.2015.07.004

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Hilar lymph node metastasis of esophageal cancer is considered to be a distant metastasis and is not indicated for surgical resection. However, its diagnosis is difficult when accompanied by inflammatory diseases such as sarcoidosis. We report two patients with esophageal cancer accompanied by bilateral hilar lymphadenopathy or accumulation on [¹⁸F]-fluorodeoxyglucose positron emission tomography-computed tomography. The first patient underwent surgery because the enlarged bilateral hilar lymph nodes were considered to be nonmalignant lesions owing to superficial carcinoma and symmetric distribution of the hilar lymph nodes. The second patient received chemotherapy, which caused the main tumor to shrink and decreased [¹⁸F]-fluorodeoxyglucose uptake. However, chemotherapy did not affect the hilar lymphadenopathy, which suggests that it was caused by reactive changes rather than metastasis. In both cases, esophagectomy and histological findings revealed that the hilar nodes were caused by sarcoid-like reactions. These findings profoundly influenced our treatment decisions for these patients.

DOI： 10.1007/s10388-014-0454-4

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We present a case of mediastinal paraganglioma with radiologic–pathologic correlation. A 48-year-old woman was found incidentally to have a middle mediastinal mass on CT. The mass showed iso-signal intensity compared to that of muscle on T1-weighted images and high signal intensity on T2-weighted images. The lesion showed intermediate intensity on diffusion-weighted imaging, and its apparent diffusion coefficient was 1.72 × 10⁻³ mm²/s. A contrast-enhanced dynamic study revealed a rapid peak and washout enhancement pattern. ¹⁸F-FDG-PET revealed abnormal uptake in the mediastinal tumor with a maximal standardized uptake value of 7.88. ¹²³I-meta-iodobenzylguanidine scintigraphy also showed abnormal uptake in the tumor. These findings corresponded to the hypervascularity, rich stroma, low nuclear/cytoplasmic ratio, and nest-forming proliferation of tumor cells with positive neuroendocrine markers.

DOI： 10.1007/s11604-015-0436-z

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Hilar lymph node metastasis of esophageal cancer is considered to be a distant metastasis and is not indicated for surgical resection. However, its diagnosis is difficult when accompanied by inflammatory diseases such as sarcoidosis. We report two patients with esophageal cancer accompanied by bilateral hilar lymphadenopathy or accumulation on [¹⁸F]-fluorodeoxyglucose positron emission tomography–computed tomography. The first patient underwent surgery because the enlarged bilateral hilar lymph nodes were considered to be nonmalignant lesions owing to superficial carcinoma and symmetric distribution of the hilar lymph nodes. The second patient received chemotherapy, which caused the main tumor to shrink and decreased [¹⁸F]-fluorodeoxyglucose uptake. However, chemotherapy did not affect the hilar lymphadenopathy, which suggests that it was caused by reactive changes rather than metastasis. In both cases, esophagectomy and histological findings revealed that the hilar nodes were caused by sarcoid-like reactions. These findings profoundly influenced our treatment decisions for these patients.

DOI： 10.1007/s10388-014-0454-4

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

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

Purpose: Yittrium-90 (⁹⁰Y) is traditionally thought of as a pure beta emitter, and is used in targeted radionuclide therapy, with imaging performed using bremsstrahlung single-photon emission computed tomography (SPECT).However, because ⁹⁰Yalso emits positrons through internal pair production with a very small branching ratio, positron emission tomography (PET) imaging is also available. Because of the insufficient image quality of ⁹⁰Y bremsstrahlung SPECT, PET imaging has been suggested as an alternative. In this paper, the authors present the Monte Carlo-based simulation-reconstruction framework for ⁹⁰Yto comprehensively analyze the PET and SPECT imaging techniques and to quantitatively consider the disadvantages associated with them. Methods: Our PET and SPECT simulation modules were developed using Monte Carlo simulation of Electrons and Photons (MCEP), developed by Dr. S. Uehara. PET code (MCEP-PET) generates a sinogram, and reconstructs the tomography image using a time-of-flight ordered subset expectation maximization (TOF-OSEM) algorithm with attenuation compensation. To evaluate MCEP-PET, simulated results of ¹⁸F PET imaging were compared with the experimental results. The results confirmed that MCEP-PET can simulate the experimental results very well. The SPECT code (MCEP-SPECT) models the collimator and NaI detector system, and generates the projection images and projection data. To save the computational time, the authors adopt the prerecorded ⁹⁰Y bremsstrahlung photon data calculated by MCEP. The projection data are also reconstructed using the OSEM algorithm. The authors simulated PET and SPECT images of a water phantom containing six hot spheres filled with different concentrations of ⁹⁰Y without background activity. The amount of activity was 163 MBq, with an acquisition time of 40 min. Results: The simulated ⁹⁰Y-PET image accurately simulated the experimental results. PET image is visually superior to SPECT image because of the lowbackground noise. The simulation reveals that the detected photon number in SPECT is comparable to that of PET, but the large fraction (approximately 75%) of scattered and penetration photons contaminates SPECT image. The lower limit of ⁹⁰Y detection in SPECT image was approximately 200 kBq/ml, while that in PET image was approximately 100 kBq/ml. Conclusions: By comparing the background noise level and the image concentration profile of both the techniques, PET image quality was determined to be superior to that of bremsstrahlung SPECT. The developed simulation codes will be very useful in the future investigations of PET and bremsstrahlung SPECT imaging of ⁹⁰Y.

DOI： 10.1118/1.4915545

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

DOI： 10.1118/1.4915545.

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

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

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

Iron deficiency and cardiac sympathetic impairment play a role in the worsening of heart failure, and these two conditions may be linked. The present study aimed to clarify the relationship between myocardial iron deficiency, cardiac sympathetic activity, and major adverse cardiac events (MACE) in patients with dilated cardiomyopathy (DCM). Cardiac T2* MRI for iron deficiency and ¹²³I-Metaiodobenzylguanidine (MIBG) imaging for cardiac sympathetic activity were performed in 46 patients with DCM. Myocardial T2* value (M-T2*) was calculated by fitting signal intensity data for mid-left ventricular septum to a decay curve using 3-Tesla scanner. ¹²³I-MIBG washout rate (MIBG-WR) was calculated using a polar-map technique with tomographic data. We analyze the ability of M-T2* and MIBG-WR to predict MACE. MIBG-WR and M-T2* were significantly greater in DCM patients with MACE than in patients without MACE. Receiver-operating-characteristics curve analysis showed that the optimal MIBG-WR and M-T2* thresholds of 35 % and 28.1 ms, and the two combination predict MACE with C-statics of 0.69, 0.73, and 0.82, respectively. Patients with MIBG-WR <35 % and M-T2* <28.1 ms had significantly lower event-free rates than those with MIBG-WR ≥35 % or M-T2* ≥28.1 ms (log-rank value = 4.35, p < 0.05). Cox hazard regression analysis showed that χ² and the hazard ratio were 3.99 and 2.15 for development of MACE in patients with MIBG-WR ≥35 % or M-T2* ≥28.1 ms (p < 0.05). Iron deficiency, expressed by a high M-T2*, and MIBG-WR were both independent predictors of MACE in patients with DCM. The two combination was a more powerful predictor of MACE than either parameter alone.

DOI： 10.1007/s10554-014-0562-1

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

DOI： 2463/mrms.2014-0052

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

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

Background: Pathological diagnosis of small lung lesions is sometimes difficult in medically inoperable patients. The purpose of this study was to evaluate the adverse events and the outcomes of stereotactic body radiation therapy (SBRT) for lung lesions which were clinically diagnosed as primary lung cancer without pathological confirmation. Methods: Between April 2003 and April 2011, 88 patients with small lung lesions which were clinically diagnosed as primary lung cancer were treated with SBRT. The median tumor size was 19 mm (range 8–40 mm). The radiation dose was 48 Gy in four fractions in all patients. The median follow-up was 23 months (range 6–91 months). Results: Recurrence was observed in 13 patients. The local control rate, progression-free survival rate, and overall survival rate at 3 years were 90, 67, and 80 %, respectively. Two patients (2.3 %) had Grade 2 radiation pneumonitis, and six patients (6.8 %) had Grade 2 rib fractures. There were no adverse events of Grade 3 or greater. Conclusions: SBRT appears to be a safe and effective treatment option for small lung lesions that are clinically diagnosed as primary lung cancer without pathological confirmation.

DOI： 10.1007/s10147-014-0698-y

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A 74-year-old woman underwent contrast-enhanced (CE) computed tomography (CT) that revealed an enlarging splenic lesion. This splenic tumor was suspected as metastasis because the patient had been diagnosed with right breast cancer with lung and right axillary lymph node metastases 4 years earlier and had undergone surgery and hormone therapy at another hospital. T₂-weighted imaging of magnetic resonance (MR) imaging demonstrated the tumor with slightly high intensity with a rim of low intensity at the margin. On dynamic contrast-enhanced (DCE)-MR imaging after intravenous administration of gadolinium diethylenetriamine pentaacetic acid, delayed enhancement was observed in the center and margin of the tumor. On positron emission tomography with 2-deoxy-2-[¹⁸F] fluoro-Dglucose (FDG) integrated with CT, the tumor showed high FDG uptake. Splenic metastasis was considered based on the imaging findings, lack of inflammation on laboratory data, and clinical course, so she underwent splenectomy. Histopathologically, the tumor was encapsulated by a fibrous structure, which was depicted as the rim at the tumor margin on T₂-weighted imaging and DCE-MR imaging. Immunohistochemical study allowed the diagnosis of inflammatory pseudotumor (IPT)-like follicular dendritic cell tumor (FDCT). FDCT is a primary neoplasm of lymph nodes that shows features of follicular dendritic cell differentiation, and it is rare at the spleen. Differential diagnosis is difficult between IPTlike FDCT and similar splenic tumors, such as IPT, splenic metastases, hamartoma and hemangioma. However, in addition to the enhancement pattern within a tumor on DCEMR imaging, detection of the capsular-like rim on MR imaging might aid the diagnosis of splenic IPT-like FDCT.

DOI： 10.2463/mrms.2014-0052

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

Methods: This study consisted of a phantom study and a clinical study. The NEMA IEC body phantom and a 40 cm diameter large phantom (LG phantom) simulating an overweight patient were used in this study. Both phantoms were filled with ¹⁸F solution with a sphere to background ratio of 4:1. The PET data were reconstructed with the baseline ordered-subsets expectation maximization (OSEM) algorithm, with the OSEM + PSF model, with the OSEM + TOF model and with the OSEM + PSF + TOF model. The clinical study was a retrospective analysis of 66 patients who underwent ¹⁸F-FDG PET/CT. The image quality was evaluated using the background variability (coefficient of variance, CV_phantom and CV_liver) and the contrast (CONT_HOT and SNR).
Results: In phantom study, the CV_phantom of the LG phantom was higher than that of the NEMA phantom. The PSF decreased the CV_phantom of the LG phantom to the NEMA phantom level. The TOF information accelerated the CV_phantom plateau earlier. The best relationship between the CV_phantom and the CONT_HOT was observed for the OSEM + PSF + TOF. In clinical study, the combination of PSF and TOF decreased the CV_liver for overweight patients to that for normal weight patients while it increased the SNR similarly between two patient groups.
Conclusion: The combination of the PSF and TOF correction improved the image quality of the LG phantom and overweight patients.
Objective: The aim of this study was to evaluate the effect of the point spread function (PSF) and time of flight (TOF) on PET/CT images of overweight patients in relation to the iteration number and the acquisition time.

DOI： 10.1007/s12149-014-0912-z

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Chylothorax is an uncommon but potentially life-threatening complication of esophagectomy. A 72-year-old man underwent thoracoscopy-assisted subtotal esophagectomy and reconstruction with a gastric tube, through a retrosternal route, after preoperative chemoradiotherapy. Chylothorax was detected after starting enteral feeding on postoperative day (POD) 7. Despite conservative therapy such as fasting, total parenteral nutrition, and octreotide administration, massive fluid drainage continued. On POD 19, lymphoscintigraphy with ^99mTc-diethylenetriamine pentaacetic acid-human serum albumin (HSA-D) was performed and the site of leakage was detected at the level of the fourth thoracic vertebra. On POD 23, the thoracic duct was ligated, following which the volume of chylothorax decreased. Lymphoscintigraphy 12 days after the reoperation showed no leakage from the thoracic duct. We recommend lymphoscintigraphy with ^99mTc-HSA-D for locating the chyle leakage site and helping decide about the operative indication.

DOI： 10.1007/s00595-014-0968-3

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Methods: Cylindrical concrete cores 5 cm in diameter and 10 cm in length were bored from the concrete wall, ceiling and floor. Core boring was performed at 18 points. The gamma-ray spectrum of each sample was measured using a high-purity germanium detector. The degree of activation of the concrete in the cyclotron vault room was analyzed, and the range and tendency toward activation in the vault room were examined.
Objective: Compact medical cyclotrons have been set up to generate the nuclides necessary for positron emission tomography. In accelerator facilities, neutrons activate the concrete used to construct the vault room; this activation increases with the use of an accelerator. The activation causes a substantial radioactive waste management problem when facilities are decommissioned. In the present study, several concrete cores from the walls, ceiling and floor of a compact medical cyclotron vault room were samples 2 years after the termination of operations, and the radioactivity concentrations of radionuclides were estimated.
Results: ⁶⁰Co and ¹⁵²Eu were identified by gamma-ray spectrometry of the concrete samples. ¹⁵²Eu and ⁶⁰Co are produced principally from the stable isotopes of europium and cobalt by neutron capture reactions. The radioactivity concentration did not vary much between the surface of the concrete and at a depth of 10 cm. Although the radioactivity concentration near the target was higher than the clearance level for radioactive waste indicated in IAEA RS-G-1.7, the mean radioactivity concentration in the walls and floor was lower than the clearance level.
Conclusion: The radioactivity concentration of the inner concrete wall of the medical cyclotron vault room was not uniform. The areas exceeding the clearance level were in the vicinity of the target, but most of the building did not exceed the clearance levels.

DOI： 10.1007/s12149-014-0918-6

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The aim of this study was to evaluate differences in dopamine transporter SPECT images among different SPECT/CT devices and to determine the most appropriate region of interest (ROI) for semiquantitative evaluation. Methods: An anthropomorphic striatal phantom was filled with ¹²³I solutions of different striatumto- background radioactivity ratios. Data were acquired using 2 SPECT/CT devices equipped with low- to medium-energy generalpurpose and low-energy high-resolution (LEHR) collimators. The SPECT images were reconstructed by filtered backprojection with both attenuation and scatter correction and then were analyzed using specific binding ratio (SBR). The most appropriate of 7 ROI types was determined, and we then compared the linearity and recovery of SBR among the different SPECT/CT devices and collimators. Results: The linearity of SBR was excellent for all types of ROIs. The ROI contouring the striatum based on the CT images showed the best recovery of SBR using mean activity in the striatal ROI (SBR_mean) (47.8%). For this ROI, the recovery of SBR_mean for SPECT/CT with a LEHR collimator with thick septa and a long hole length was 61.6%- significantly higher than that of other devices. Conclusion: The ROI contouring the striatum based on CT images was considered appropriate for evaluating dopamine transporter SPECT/CT. Among the different SPECT/CT devices, an LEHR collimator designed for ^123II imaging is recommended.

DOI： 10.2967/jnmt.114.149401

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

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

Although patients with castration-resistant prostate cancer frequently have metastases to the bone, they have a relatively favorable prognosis. Therefore, it is important to keep or improve the level of patient's quality of life. The use of strontium-89 for the management of the pain from bone metastasis was approved in 2007 in Japan. A new bone-targeting radiopharmaceuticals using radium-223 is also promising, because a randomized trial showed an overall survival advantage of radium-223 in prostate patients with bone metastases. In this review, we summarize the role of targeted radionuclide therapy for castration-resistant prostate cancer, focusing on strontium-89 and radium-223.

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

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

FDG-PET is increasingly being used for assessment of the staging, for evaluating the response to treatment, and for monitoring the reactions to therapy in malignant lymphoma. This review will highlight the most important applications of FDG-PET in lymphoma, focusing on the advantages and pitfalls of this imaging, and past and ongoing efforts to standardize the use of FDG-PET, particularly in response to assessment and therapy monitoring.

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Objective: We evaluated the accuracy of amplitude gating PET (AG-PET) compared with phase gating PET (PG-PET) in relation to respiratory motion patterns based on a phantom analysis.
Method: We used a NEMA IEC body phantom filled with an ¹⁸F solution with a 4:1 sphere-to-background radioactivity ratio (12.6 and 2.97 kBq/mL). PET/CT scans were acquired in a motionless and moving state on a Biograph mCT. The respiratory movements were simulated by four different waveform patterns consisting of ideal breathing, breathing with a pause period, breathing with a variable amplitude and breathing with a changing baseline. AG-PET selects the narrow bandwidth containing 20 % of the respiratory cycle. PG-PET was reconstructed with five gates. The image quality was physically assessed using the percent contrast (Q_H,10mm), background variability (N_10mm) recovery coefficient (RC), and sphere volumes.
Result: In regular motion patterns with ideal breathing and breathing with a pause period, the Q_H,10mm, RC and sphere volumes were not different between AG-PET and PG-PET. In the variable amplitude pattern, the Q_H,10mm of AG-PET was higher than that of PG-PET (35.8 vs 28.2 %), the RC of AG-PET was higher than that of PG-PET and sphere volume of AG-PET was smaller than that of PG-PET (6.4 vs 8.6 mL). In the changing baseline pattern, the Q_H,10mm of AG-PET was higher than that of PG-PET (42.4 vs 16.7 %), the RC of AG-PET was higher than that of PG-PET and sphere volume of AG-PET was smaller than that of PG-PET (6.2 vs 9.8 mL). The N_10mm did not differ between AG-PET and PG-PET, irrespective of the motion pattern.
Conclusion: Amplitude gating PET is considered to be more accurate than phase gating PET for examining unstable respiratory motion patterns, such as those involving a variable amplitude or changing baseline.

DOI： 10.1007/s12149-014-0870-5

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

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

Acute gastric anisakiasis is caused by the consumption of raw or undercooked fish containing Anisakis larvae. Although several reports have demonstrated the CT features of acute gastric anisakiasis, little is known about the FDG PET/CT findings. We report a 59-year-old woman who underwent FDG PET/CT and was finally diagnosed as having acute gastric anisakiasis. The PET/CT demonstrated focal FDG accumulation in the fornix of the gastric wall and lymph nodes in the lesser curvature and paraaortic regions.

DOI： 10.1097/RLU.0b013e3182a23d17

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

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

In oncology, the apparent diffusion coefficient (ADC) measured by diffusion-weighted MR imaging (DWI) and the standardized uptake value (SUV) from ^18F-FDG PET have similar clinical applications. The purpose of this study was to assess the correlation between the ADC and SUV and compare their potential in the diagnosis and prediction of prognosis in breast tumors. Methods: Seventy-nine female patients (age range, 19-69 y; average, 49.1 y) with 83 pathologically proven breast tumors were recruited. The diagnoses consisted of 70 malignant breast tumors (65 cases of invasive ductal carcinoma, 1 of medullary carcinoma, 1 of mucinous carcinoma, 1 of squamous cell carcinoma, and 2 of micropapillary carcinoma) and 13 benign breast tumors (4 cases of fibroadenoma, 4 of mastopathy, 3 of adenosis with atypia, and 2 of benign phyllodes tumor). All patients underwent mammary gland MR imaging with DWI and ^18F-FDG PET within a 2-wk interval. The patients' ADCs and SUVs were measured within the tumor by DWI and ^18F-FDG PET, respectively. For the malignant tumors, we evaluated the relationships among ADC, SUV, histopathologic appearance, and long-term prognosis. Results: A significant difference (P < 0.05) was observed in both parameters (ADC and SUV) between the benign and malignant breast tumors, and the difference was more significant when we introduced a new parameter, SUV/ADC. There was a weak inverse correlation between ADC and SUV (r = -0.36; P = 0.06) among the total tumors; however, this correlation was not significant within the group of malignant tumors. High SUV was found to correlate with larger tumor size, higher nuclear grade, and the triple-negative hormonal receptor profile. High ADC was revealed to be correlated with negative progesterone receptor and positive human epidermal growth factor receptor 2 profile. Higher SUVs also showed a correlation with poor prognosis. No correlation was seen between ADC and prognosis. Conclusion: Both SUV and ADC are helpful parameters in differentiating benign from malignant breast tumors. The use of SUV and ADC in combination may help in the diagnosis because of their inverse relationship. High preoperative SUV was associated with poor prognosis, but the contribution of ADC to prognosis prediction was small.

DOI： 10.2967/jnumed.113.129395

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Objectives: This study investigated the association between several biological markers and fluorine-18 fluorodeoxyglucose (FDG) uptake in patients with hepatocellular carcinoma.
Methods: Forty-two patients with hepatocellular carcinoma who underwent FDG positron emission tomography were included in the study. Tumor sections were immunohistochemically stained for phosphorylated signal transducer and activator of transcription 3 (pSTAT3), hypoxia-inducible factor 1α (HIF1α), glucose transporter 1 (GLUT1), GLUT2, GLUT3, and GLUT4.
Results: The high standardized uptake value (SUV) group showed larger tumor size, more frequent vascular invasion, and poorer differentiation compared with the low SUV group. The high SUV group also showed significantly higher immunohistochemical expression of pSTAT3, HIF1α, and GLUT1. The GLUT1 high-expression group showed higher α-fetoprotein (a tumor marker) and poorer differentiation than did the GLUT1 low-expression group.
Conclusions: Our study indicates that FDG uptake is associated with the expression of pSTAT3, HIF1α, and GLUT1 in hepatocellular carcinoma. The expression of these proteins shows a correlation with poor differentiation and vascular invasion.

DOI： 10.1309/AJCPG8AFJ5NRKLLM

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PURPOSE: Many cases of unexpected radioiodine uptake have been reported, including physiological uptake in healthy tissue and in both benign and malignant nonthyroidal lesions. However, iodine uptake in the uterus has not been well assessed. In this article, we systemically analyzed iodine uptake in the uterus and identified the site in which uptake occurred. MATERIALS AND METHODS: Seventy-six female patients who underwent SPECT/CT from neck to pelvis were included in this study; 5 patients with uterine uptake received pelvic MRI. Iodine uptake in the uterus was diagnosed with SPECT/CT and compared with the findings of the MRI. Serum TSH level, administered dose of iodine-131 and number of radioiodine therapies were compared between the 2 groups with and without iodine uptake in the uterus. RESULTS: Twenty (26.3%) of 76 patients showed iodine uptake in the uterine cervix on SPECT/CT. It was difficult to distinguish the uptake in the uterus from that in the urinary bladder or rectum using only planar images. The patients with the uterine uptake were younger than those without (median age, 46.5 vs. 62, P = 0.011). There were no significant differences in serum TSH level, administered dose of iodine-131, or number of radioiodine therapies between the 2 groups. In all instances of the 5 patients who underwent pelvic MRI, iodine uptake in the uteri was located in nabothian cysts. CONCLUSION: Iodine uptake in the uterus is frequently found if pelvic SPECT/CT is performed. Nabothian cysts are a predominant cause of iodine uptake in the uterine cervix.

DOI： 10.1097/RLU.0000000000000504

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

PURPOSE: Many cases of unexpected radioiodine uptake have been reported, including physiological uptake in healthy tissue and in both benign and malignant nonthyroidal lesions. However, iodine uptake in the uterus has not been well assessed. In this article, we systemically analyzed iodine uptake in the uterus and identified the site in which uptake occurred. MATERIALS AND METHODS: Seventy-six female patients who underwent SPECT/CT from neck to pelvis were included in this study; 5 patients with uterine uptake received pelvic MRI. Iodine uptake in the uterus was diagnosed with SPECT/CT and compared with the findings of the MRI. Serum TSH level, administered dose of iodine-131 and number of radioiodine therapies were compared between the 2 groups with and without iodine uptake in the uterus. RESULTS: Twenty (26.3%) of 76 patients showed iodine uptake in the uterine cervix on SPECT/CT. It was difficult to distinguish the uptake in the uterus from that in the urinary bladder or rectum using only planar images. The patients with the uterine uptake were younger than those without (median age, 46.5 vs. 62, P = 0.011). There were no significant differences in serum TSH level, administered dose of iodine-131, or number of radioiodine therapies between the 2 groups. In all instances of the 5 patients who underwent pelvic MRI, iodine uptake in the uteri was located in nabothian cysts. CONCLUSION: Iodine uptake in the uterus is frequently found if pelvic SPECT/CT is performed. Nabothian cysts are a predominant cause of iodine uptake in the uterine cervix.

DOI： 10.1097/RLU.0000000000000504

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

Purpose The purpose of this study was to investigate the effects of point-spread function (PSF) and time-of-flight (TOF) on the standardized uptake value (SUV) of lymph node metastasis in FDG-PET/CT. Materials and methods This study evaluated 41 lymph node metastases in 15 patients who had undergone ¹⁸F-FDG PET/CT. The lesion diameters were 2.5 cm or less. The mean short-axis diameter of the lymph nodes was 10.5 ± 3.7 mm (range 4.6-22.8 mm). The PET data were reconstructed with baseline OSEM algorithm, with OSEM + PSF, with OSEM + TOF and with OSEM + PSF + TOF. A semi-quantitative analysis was performed using the maximum and mean SUV of lymph node metastases (SUV _max and SUV_mean) and mean SUV of normal lung tissue (SUV_lung). We also evaluated image quality using the signal-to-noise ratio in the liver (SNR_liver). Results Both PSF and TOF increased the SUV of lymph node metastases. The combination of PSF and TOF increased the SUV_max by 43.3% and the SUV_mean by 31.6% compared with conventional OSEM. By contrast, the SUV_lung was not influenced by PSF and TOF. TOF significantly improved the SNR_liver. Conclusion PSF and TOF both increased the SUV of lymph node metastases. Although PSF and TOF are considered to improve small-lesion detectability, it is important to be aware that PSF and TOF influence the accuracy of quantitative measurements.

DOI： 10.1016/j.ejrad.2013.09.030

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

Hepatocellular adenoma (HCA) is a benign liver neoplasm composed of hepatocytes. We experienced HCA demonstrating a high uptake of ¹⁸F-fluorodeoxyglucose (FDG) on positron emission tomography-computed tomography, mimicking a malignant tumor. The mechanism underlying the uptake of FDG has not been identified. Here, we discuss that an enhancement of glucose metabolism via an increased expression of glucose transporter 2 may have a role in the high uptake of FDG shown by HCAs.

DOI： 10.1016/j.clinimag.2014.06.005

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

DOI： 10.1176/appi.neuropsych.13020031

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

Here we propose the fusion imaging of myocardial SPECT/PET and MRI, and demonstrate new insights in dilated cardiomyopathy (DCM) and cardiac sarcoidosis. In DCM, impaired cardiac sympathetic activity expressed by MIBG scintigraphy was associated with spatial dyssynchrony obtained from tagging MRI. Myocardial T2^∗ value and MIBG uptake were independents predictors of major cardiac adverse events in DCM. Fusion image of late gadolinium enhanced MRI and FDG-PET helps to differentiate cardiac sarcoidosis from myocarditis and DCM. Myocardial thickening and T2 high intensity on MRI and high myocardial uptake on FDG-PET were often seen in non-responder to steroid therapy in cardiac sarcoidosis.

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

DOI： 10.1176/appi.neuropsych.13020031

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

Here we propose the fusion imaging of myocardial SPECT/PET and MRI, and demonstrate new insights in dilated cardiomyopathy (DCM) and cardiac sarcoidosis. In DCM, impaired cardiac sympathetic activity expressed by MIBG scintigraphy was associated with spatial dyssynchrony obtained from tagging MRI. Myocardial T2^∗ value and MIBG uptake were independents predictors of major cardiac adverse events in DCM. Fusion image of late gadolinium enhanced MRI and FDG-PET helps to differentiate cardiac sarcoidosis from myocarditis and DCM. Myocardial thickening and T2 high intensity on MRI and high myocardial uptake on FDG-PET were often seen in non-responder to steroid therapy in cardiac sarcoidosis.

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

Purpose: The purpose of this study was to evaluate the clinical usefulness of partial volume effect (PVE)-corrected F-18 FDG PET/CT for predicting I-131 accumulation in metastatic lymph nodes (mLNs) during I-131 therapy for papillary thyroid carcinoma (PTC). Methods: Sixty-five mLNs in 31 PTC patients who underwent F-18 FDG PET/CT in an initial radioiodine therapy (RIT) were retrospectively evaluated. Of these, 25 mLNs were I-131-positive and 40 were I-131-negative. SUVmax and SUVmax with PVE correction (cSUVmax) were measured for each mLN, where PVE correction was performed utilizing a simple table lookup correction method. Then, SUVmax/cSUVmax was compared between I-131-positive and I-131-negative mLNs, including the analyses for the mLNs with small-sized (<1 cm) and weak FDG accumulation (SUVmax <3.5). The predictability for I-131 accumulation with SUVmax/cSUVmax was also compared. Results: For all 65 mLNs, SUVmax/cSUVmax was significantly higher in I-131-negative than I-131-positive mLNs (p < 0.0001). Only in cSUVmax, I-131-negative mLNs were significantly higher than I-131-positive, in terms of the 30 small-sized mLNs (p = 0.0001) and 14 mLNs with weak FDG uptake (p = 0.007). The highest accuracy in predictability for I-131 accumulation was significantly better with cSUVmax (92 %) than SUVmax (62 %) (p < 0.0001). Conclusion: PVE-corrected F-18 FDG PET/CT is a valuable predictor of I-131 accumulation in mLNs during RIT.

DOI： 10.1007/s12149-013-0767-8

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

Purpose: The purpose of this study was to evaluate the clinical usefulness of partial volume effect (PVE)-corrected F-18 FDG PET/CT for predicting I-131 accumulation in metastatic lymph nodes (mLNs) during I-131 therapy for papillary thyroid carcinoma (PTC). Methods: Sixty-five mLNs in 31 PTC patients who underwent F-18 FDG PET/CT in an initial radioiodine therapy (RIT) were retrospectively evaluated. Of these, 25 mLNs were I-131-positive and 40 were I-131-negative. SUVmax and SUVmax with PVE correction (cSUVmax) were measured for each mLN, where PVE correction was performed utilizing a simple table lookup correction method. Then, SUVmax/cSUVmax was compared between I-131-positive and I-131-negative mLNs, including the analyses for the mLNs with small-sized (<1 cm) and weak FDG accumulation (SUVmax <3.5). The predictability for I-131 accumulation with SUVmax/cSUVmax was also compared. Results: For all 65 mLNs, SUVmax/cSUVmax was significantly higher in I-131-negative than I-131-positive mLNs (p < 0.0001). Only in cSUVmax, I-131-negative mLNs were significantly higher than I-131-positive, in terms of the 30 small-sized mLNs (p = 0.0001) and 14 mLNs with weak FDG uptake (p = 0.007). The highest accuracy in predictability for I-131 accumulation was significantly better with cSUVmax (92 %) than SUVmax (62 %) (p < 0.0001). Conclusion: PVE-corrected F-18 FDG PET/CT is a valuable predictor of I-131 accumulation in mLNs during RIT.

DOI： 10.1007/s12149-013-0767-8

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

The purpose of this study was to assess the efficacy of 18F-fluoro-2-deoxy-glucose uptake positron emission tomography (FDG-PET) for the prediction of outcome in definitive chemoradiotherapy (CRT) for esophageal cancer. We enrolled 56 patients with esophageal cancer treated with definitive CRT and examined by FDG-PET before treatment. We examined the correlation of the maximum standardized uptake value (SUVmax) in FDG-PET of the primary tumor with overall survival (OS), progression-free survival (PFS), local control (LC) and response of the primary tumor. After definitive CRT, 30 patients had a clinical complete response (CR), making the CR rate 54%. For all 56 patients, the 2-year OS rate, PFS rate and LC rates were 64%, 38% and 51%, respectively. We divided the patients into two groups according to SUVmax: SUVmax < 10 (low-SUV) and <10 (high-SUV). The 2-year OS rates in the low- and high-SUV groups were 100% and 41%, the PFS rates were 73% and 19%, the LC rates were 71% and 39%, and the CR rates were 100% and 32%, respectively. A univariate analysis revealed significant differences between the low- and high-SUV group in OS, PFS, LC and response (P = 0.0005, 0.0002, 0.048, and <0.0001, respectively). SUVmax and T stage were significantly associated with OS, PFS, LC and response. A multivariate analysis showed significant differences between the SUVmax <10 and ≥10 groups in overall survival and response (P < 0.05). Our result suggests that the SUVmax in FDG-PET of the primary tumor before treatment may have prognostic value for esophageal cancer.

DOI： 10.1093/jrr/rrt021

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

The purpose of this study was to assess the efficacy of 18F-fluoro-2-deoxy-glucose uptake positron emission tomography (FDG-PET) for the prediction of outcome in definitive chemoradiotherapy (CRT) for esophageal cancer. We enrolled 56 patients with esophageal cancer treated with definitive CRT and examined by FDG-PET before treatment. We examined the correlation of the maximum standardized uptake value (SUVmax) in FDG-PET of the primary tumor with overall survival (OS), progression-free survival (PFS), local control (LC) and response of the primary tumor. After definitive CRT, 30 patients had a clinical complete response (CR), making the CR rate 54%. For all 56 patients, the 2-year OS rate, PFS rate and LC rates were 64%, 38% and 51%, respectively. We divided the patients into two groups according to SUVmax: SUVmax < 10 (low-SUV) and <10 (high-SUV). The 2-year OS rates in the low- and high-SUV groups were 100% and 41%, the PFS rates were 73% and 19%, the LC rates were 71% and 39%, and the CR rates were 100% and 32%, respectively. A univariate analysis revealed significant differences between the low- and high-SUV group in OS, PFS, LC and response (P = 0.0005, 0.0002, 0.048, and <0.0001, respectively). SUVmax and T stage were significantly associated with OS, PFS, LC and response. A multivariate analysis showed significant differences between the SUVmax <10 and ≥10 groups in overall survival and response (P < 0.05). Our result suggests that the SUVmax in FDG-PET of the primary tumor before treatment may have prognostic value for esophageal cancer.

DOI： 10.1093/jrr/rrt021

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

Background: Impairment of cardiac sympathetic activity has various detrimental effects on cardiac function. The purpose was to investigate the relationship between left ventricular (LV) dyssynchrony and cardiac sympathetic activity in non-ischemic heart failure (HF). Methods: Twenty-seven patients with non-ischemic HF were enrolled. Cardiac sympathetic activity was assessed by heart-to-mediastinum ratio (H/M ratio) on ¹²³I- Metaiodobenzylguanidine scintigraphy. LV dyssynchrony was assessed by cross-correlation analysis of time curves of myocardial circumferential strains delivered from cine-tagging MR images. Temporal dyssynchrony was defined as contraction delay between septal and lateral segments >110 milliseconds. Spatial dyssynchrony was defined as the negative value of the maximum correlation for the two strain time curves. Results: H/M ratio was significantly lower for patients with spatial dyssynchrony compared to patients without (1.8 ± 0.3 vs 2.1 ± 0.3, P <.05). There was no difference between patients with and without temporal dyssynchrony (2.0 ± 0.2 vs 2.0 ± 0.3). The incidence of spatial dyssynchrony was significantly higher in patients with H/M ratio <2.0 than those whose ratios were ≥2.0 (75% vs 20%, P =.001). There was no difference in the incidence of temporal dyssynchrony between the two groups (17% vs 20%). Conclusion: Impairment of cardiac sympathetic activity was found to be associated with spatial dyssynchrony in patients with non-ischemic HF.

DOI： 10.1007/s12350-013-9715-1

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

Background: Impairment of cardiac sympathetic activity has various detrimental effects on cardiac function. The purpose was to investigate the relationship between left ventricular (LV) dyssynchrony and cardiac sympathetic activity in non-ischemic heart failure (HF). Methods: Twenty-seven patients with non-ischemic HF were enrolled. Cardiac sympathetic activity was assessed by heart-to-mediastinum ratio (H/M ratio) on ¹²³I- Metaiodobenzylguanidine scintigraphy. LV dyssynchrony was assessed by cross-correlation analysis of time curves of myocardial circumferential strains delivered from cine-tagging MR images. Temporal dyssynchrony was defined as contraction delay between septal and lateral segments >110 milliseconds. Spatial dyssynchrony was defined as the negative value of the maximum correlation for the two strain time curves. Results: H/M ratio was significantly lower for patients with spatial dyssynchrony compared to patients without (1.8 ± 0.3 vs 2.1 ± 0.3, P <.05). There was no difference between patients with and without temporal dyssynchrony (2.0 ± 0.2 vs 2.0 ± 0.3). The incidence of spatial dyssynchrony was significantly higher in patients with H/M ratio <2.0 than those whose ratios were ≥2.0 (75% vs 20%, P =.001). There was no difference in the incidence of temporal dyssynchrony between the two groups (17% vs 20%). Conclusion: Impairment of cardiac sympathetic activity was found to be associated with spatial dyssynchrony in patients with non-ischemic HF.

DOI： 10.1007/s12350-013-9715-1

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

: The PET image quality of overweight patients and patients who receive low injected doses deteriorates because of increases in statistical noise. The purpose of this study was to investigate the benefits of the point-spread function (PSF) and time-of-flight (TOF) for PET/CT image quality in such patients. METHODS: The PET images were reconstructed using the baseline ordered-subsets expectation-maximization algorithm (OSEM), OSEM + PSF, OSEM + TOF, and OSEM + PSF + TOF. In the phantom study, we used a National Electrical Manufacturers Association body phantom with different radioactivity concentrations and analyzed image quality using the coefficient of variance in the background (CVphantom). In the clinical study, we retrospectively studied 39 patients who underwent clinical F-FDG PET/CT. The patients were classified into groups based on body mass index and injected dose. Image quality was evaluated using the CV in the liver (CVliver). RESULTS: In the phantom study, PSF and TOF improved the CVphantom, especially in low-activity models. Among all of the reconstructions, the best CVphantom was obtained with OSEM + PSF + TOF. In the clinical study, the CVliver of the low-dose group with OSEM + PSF + TOF was comparable to that of the high-dose group with conventional OSEM. CONCLUSIONS: Point-spread function and TOF improved PET/CT image quality for overweight patients who received a lower injected dose. Therefore, the use of PSF and TOF is suggested to maintain the image quality of such patients without extending scanning times. It is greatly beneficial to obtain sufficient image quality for larger patients, especially in delivery institutions where the injection dose cannot be easily increased.

DOI： 10.1097/RLU.0b013e31828da3bd

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

: The PET image quality of overweight patients and patients who receive low injected doses deteriorates because of increases in statistical noise. The purpose of this study was to investigate the benefits of the point-spread function (PSF) and time-of-flight (TOF) for PET/CT image quality in such patients. METHODS: The PET images were reconstructed using the baseline ordered-subsets expectation-maximization algorithm (OSEM), OSEM + PSF, OSEM + TOF, and OSEM + PSF + TOF. In the phantom study, we used a National Electrical Manufacturers Association body phantom with different radioactivity concentrations and analyzed image quality using the coefficient of variance in the background (CVphantom). In the clinical study, we retrospectively studied 39 patients who underwent clinical F-FDG PET/CT. The patients were classified into groups based on body mass index and injected dose. Image quality was evaluated using the CV in the liver (CVliver). RESULTS: In the phantom study, PSF and TOF improved the CVphantom, especially in low-activity models. Among all of the reconstructions, the best CVphantom was obtained with OSEM + PSF + TOF. In the clinical study, the CVliver of the low-dose group with OSEM + PSF + TOF was comparable to that of the high-dose group with conventional OSEM. CONCLUSIONS: Point-spread function and TOF improved PET/CT image quality for overweight patients who received a lower injected dose. Therefore, the use of PSF and TOF is suggested to maintain the image quality of such patients without extending scanning times. It is greatly beneficial to obtain sufficient image quality for larger patients, especially in delivery institutions where the injection dose cannot be easily increased.

DOI： 10.1097/RLU.0b013e31828da3bd

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

Purpose: To investigate myocardial viability in chronic ischemic heart disease by myocardial perfusion and regional contraction analysis using 256-slice MSCT coronary angiography (CCTA). Methods: In 30 patients with prior myocardial infarction (MI), CCTA with retrospective ECG-gating and stress-redistribution thallium-201 SPECT were performed. Using the same raw data as used for CCTA, myocardial perfusion imaging (CT-MPI) was reconstructed at four phases during the cardiac cycle. Mean myocardial attenuation and wall thickness at end-systole and end-diastole were measured in the MI areas depicted by SPECT, and they were compared between viable and non-viable segments categorized by SPECT. Results: End-systolic thickness was significantly greater for viable than for non-viable segments (12.0 ± 3.2 vs. 9.6 ± 3.5 mm, p = 0.0017). There was no difference in end-diastolic thickness. Myocardial attenuation was significantly higher for viable than for non-viable segments in the subendocardium (62 ± 13 vs. 70 ± 11 HU, p = 0.003) and the epicardium (65 ± 13 vs. 80 ± 15 HU, p = 0.0002). Conclusion: The systolic wall thinning and epicardial low-attenuation areas were the indicative findings of CT-MPI for non-viable segments in the prior MI.

DOI： 10.1007/s11604-012-0159-3

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

Purpose: To investigate myocardial viability in chronic ischemic heart disease by myocardial perfusion and regional contraction analysis using 256-slice MSCT coronary angiography (CCTA). Methods: In 30 patients with prior myocardial infarction (MI), CCTA with retrospective ECG-gating and stress-redistribution thallium-201 SPECT were performed. Using the same raw data as used for CCTA, myocardial perfusion imaging (CT-MPI) was reconstructed at four phases during the cardiac cycle. Mean myocardial attenuation and wall thickness at end-systole and end-diastole were measured in the MI areas depicted by SPECT, and they were compared between viable and non-viable segments categorized by SPECT. Results: End-systolic thickness was significantly greater for viable than for non-viable segments (12.0 ± 3.2 vs. 9.6 ± 3.5 mm, p = 0.0017). There was no difference in end-diastolic thickness. Myocardial attenuation was significantly higher for viable than for non-viable segments in the subendocardium (62 ± 13 vs. 70 ± 11 HU, p = 0.003) and the epicardium (65 ± 13 vs. 80 ± 15 HU, p = 0.0002). Conclusion: The systolic wall thinning and epicardial low-attenuation areas were the indicative findings of CT-MPI for non-viable segments in the prior MI.

DOI： 10.1007/s11604-012-0159-3

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

Purpose: To investigate myocardial viability in chronic ischemic heart disease by myocardial perfusion and regional contraction analysis using 256-slice MSCT coronary angiography (CCTA). Methods: In 30 patients with prior myocardial infarction (MI), CCTA with retrospective ECG-gating and stress-redistribution thallium-201 SPECT were performed. Using the same raw data as used for CCTA, myocardial perfusion imaging (CT-MPI) was reconstructed at four phases during the cardiac cycle. Mean myocardial attenuation and wall thickness at end-systole and end-diastole were measured in the MI areas depicted by SPECT, and they were compared between viable and non-viable segments categorized by SPECT. Results: End-systolic thickness was significantly greater for viable than for non-viable segments (12.0 ± 3.2 vs. 9.6 ± 3.5 mm, p = 0.0017). There was no difference in end-diastolic thickness. Myocardial attenuation was significantly higher for viable than for non-viable segments in the subendocardium (62 ± 13 vs. 70 ± 11 HU, p = 0.003) and the epicardium (65 ± 13 vs. 80 ± 15 HU, p = 0.0002). Conclusion: The systolic wall thinning and epicardial low-attenuation areas were the indicative findings of CT-MPI for non-viable segments in the prior MI.

DOI： 10.1007/s11604-012-0159-3

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

DOI： 10.1212/CPJ.0b013e318296f263

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

PURPOSE: The purpose of this study was to propose a new index that quantifies the heterogeneity of myocardial uptake on gated myocardial perfusion SPECT (GMPS) with Tl and investigate its utility in diagnosing multivessel coronary artery disease (CAD). METHODS: In 51 patients with CAD, adenosine-stress Tl GMPS and coronary angiography (CAG) were performed. On the basis of the American Heart Association's 17-segment model, segmental percentage uptake on stress, and redistribution images of GMPS were measured at end-systole and end-diastole. The coefficient of variance (CV) of 17 segmental percentage uptake for each patient was used as an estimate of the heterogeneity of myocardial uptake. According to the results of CAG, patients were divided into insignificant coronary artery stenosis (insignificant-CAD), single-vessel CAD, and multivessel CAD groups. The differences in CV among the 3 groups were analyzed by 1-way analysis of variance and Tukey-Kramer test. The diagnostic capability for multivessel CAD was analyzed using the receiver operating characteristics (ROC) curve analysis. RESULTS: Stress end-diastolic CV for patients with multivessel CAD [mean (SD), 18.1% (3.5%)] was significantly greater than that for single-vessel CAD [12.8% (2.9%), P < 0.0001] and insignificant-CAD [10.1% (0.9%), P < 0.0001]. Stress end-systolic CV for patients with multivessel CAD [23.4% (5.2%)] was significantly greater than that for insignificant-CAD [16.5% (4.1%), P = 0.002], whereas there was no difference between single-vessel [20.9% (6.1%)] and multivessel CAD. Using an optimal cutoff of stress end-diastolic CV diagnosed multivessel CAD with a sensitivity of 84%, a specificity of 92%, an accuracy of 88%, and an area under the curve of 0.89. CONCLUSIONS: The heterogeneity of myocardial percentage uptake on Tl GMPS was correlated with the severity of CAD. Stress end-diastolic CV value is a candidate index for differentiating patients with multivessel CAD from single-vessel CAD and insignificant-CAD.

DOI： 10.1097/RLU.0b013e3182638e46

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

PURPOSE: The purpose of this study was to propose a new index that quantifies the heterogeneity of myocardial uptake on gated myocardial perfusion SPECT (GMPS) with Tl and investigate its utility in diagnosing multivessel coronary artery disease (CAD). METHODS: In 51 patients with CAD, adenosine-stress Tl GMPS and coronary angiography (CAG) were performed. On the basis of the American Heart Association's 17-segment model, segmental percentage uptake on stress, and redistribution images of GMPS were measured at end-systole and end-diastole. The coefficient of variance (CV) of 17 segmental percentage uptake for each patient was used as an estimate of the heterogeneity of myocardial uptake. According to the results of CAG, patients were divided into insignificant coronary artery stenosis (insignificant-CAD), single-vessel CAD, and multivessel CAD groups. The differences in CV among the 3 groups were analyzed by 1-way analysis of variance and Tukey-Kramer test. The diagnostic capability for multivessel CAD was analyzed using the receiver operating characteristics (ROC) curve analysis. RESULTS: Stress end-diastolic CV for patients with multivessel CAD [mean (SD), 18.1% (3.5%)] was significantly greater than that for single-vessel CAD [12.8% (2.9%), P < 0.0001] and insignificant-CAD [10.1% (0.9%), P < 0.0001]. Stress end-systolic CV for patients with multivessel CAD [23.4% (5.2%)] was significantly greater than that for insignificant-CAD [16.5% (4.1%), P = 0.002], whereas there was no difference between single-vessel [20.9% (6.1%)] and multivessel CAD. Using an optimal cutoff of stress end-diastolic CV diagnosed multivessel CAD with a sensitivity of 84%, a specificity of 92%, an accuracy of 88%, and an area under the curve of 0.89. CONCLUSIONS: The heterogeneity of myocardial percentage uptake on Tl GMPS was correlated with the severity of CAD. Stress end-diastolic CV value is a candidate index for differentiating patients with multivessel CAD from single-vessel CAD and insignificant-CAD.

DOI： 10.1097/RLU.0b013e3182638e46

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

DOI： 10.1212/CPJ.0b013e318296f263

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

PURPOSE: The purpose of this study was to propose a new index that quantifies the heterogeneity of myocardial uptake on gated myocardial perfusion SPECT (GMPS) with Tl and investigate its utility in diagnosing multivessel coronary artery disease (CAD). METHODS: In 51 patients with CAD, adenosine-stress Tl GMPS and coronary angiography (CAG) were performed. On the basis of the American Heart Association's 17-segment model, segmental percentage uptake on stress, and redistribution images of GMPS were measured at end-systole and end-diastole. The coefficient of variance (CV) of 17 segmental percentage uptake for each patient was used as an estimate of the heterogeneity of myocardial uptake. According to the results of CAG, patients were divided into insignificant coronary artery stenosis (insignificant-CAD), single-vessel CAD, and multivessel CAD groups. The differences in CV among the 3 groups were analyzed by 1-way analysis of variance and Tukey-Kramer test. The diagnostic capability for multivessel CAD was analyzed using the receiver operating characteristics (ROC) curve analysis. RESULTS: Stress end-diastolic CV for patients with multivessel CAD [mean (SD), 18.1% (3.5%)] was significantly greater than that for single-vessel CAD [12.8% (2.9%), P < 0.0001] and insignificant-CAD [10.1% (0.9%), P < 0.0001]. Stress end-systolic CV for patients with multivessel CAD [23.4% (5.2%)] was significantly greater than that for insignificant-CAD [16.5% (4.1%), P = 0.002], whereas there was no difference between single-vessel [20.9% (6.1%)] and multivessel CAD. Using an optimal cutoff of stress end-diastolic CV diagnosed multivessel CAD with a sensitivity of 84%, a specificity of 92%, an accuracy of 88%, and an area under the curve of 0.89. CONCLUSIONS: The heterogeneity of myocardial percentage uptake on Tl GMPS was correlated with the severity of CAD. Stress end-diastolic CV value is a candidate index for differentiating patients with multivessel CAD from single-vessel CAD and insignificant-CAD.

DOI： 10.1097/RLU.0b013e3182638e46

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

The aim of this study was to investigate the effects of the pointspread function (PSF) and time-of-flight (TOF) on improving ¹⁸FFDG PET/CT images in relation to reconstruction parameters and noise-equivalent counts (NEC). Methods: This study consisted of a phantom study and a retrospective analysis of 39 consecutive patients who underwent clinical ¹⁸F-FDG PET/CT. The body phantom of the National Electrical Manufacturers Association and International Electrotechnical Commission with a 10-mm-diameter sphere was filled with an ¹⁸F-FDG solution with a 4:1 radioactivity ratio compared with the background. The PET data were reconstructed with the baseline ordered-subsets expectation maximization (OSEM) algorithm, with the OSEM+PSF model, with the OSEM+TOF model, and with the OSEM+PSF+TOF model. We evaluated image quality by visual assessment, the signal-to-noise ratio of the 10-mm sphere (SNR_{10 mm}), the contrast of the 10-mm sphere, and the coefficient of variance in the phantom study and then determined the optimal reconstruction parameters. We also examined the effects of PSF and TOF on the quality of clinical images using the signal-to-noise ratio in the liver (SNR_liver) in relation to the NEC in the liver (ENC_liver). Results: In the phantom study, the SNR_{10 mm} was the highest for the OSEM+PSF+TOF model, and the highest value was obtained at iteration 2 for algorithms with the TOF and at iteration 3 for those without the TOF. In terms of a postsmoothing filter full width at half maximum (FWHM), the high SNR _{10 mm} was obtained with no filtering or was smaller than 2 mm for algorithms with PSF and was 4-6 mm for those without PSF. The balance between the contrast recovery and noise is different for algorithms with either PSF or TOF. A combination of PSF and TOF improved SNR_{10 mm}, contrast, and coefficient of variance, especially with a small-FWHM gaussian filter. In the clinical study, the SNR_liver of the low- ENC_liver group in the OSEM+PSF+TOF model was compared with that of the high-ENC_liver group in conventional OSEM. The PSF+TOF improved the SNR_liver by about 24.9% ± 9.81%. Conclusion: A combination of PSF and TOF clearly improves image quality, whereas optimization of the reconstruction parameters is necessary to obtain the best performance for PSF or TOF. Furthermore, this combination has the potential to provide good image quality with either lower activity or shorter acquisition time, thus improving patient comfort and reducing the radiation burden. COPYRIGHT

DOI： 10.2967/jnumed.112.103861

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

Purpose: To retrospectively determine the incremental diagnostic value of adding single photon emission computed tomography/ computed tomography (SPECT/CT) to whole-body scintigraphy with iodine 131 (¹³¹I) compared with scintigraphy alone after radioiodine therapy in patients with well-differentiated thyroid carcinoma. Materials and Methods: This retrospective study was institutional review board approved; written informed consent was waived. The study included 147 patients (94 female, 53 male patients; mean age, 51 years) with well-differentiated thyroid carcinoma treated with radioiodine therapy between October 2009 and August 2010. Whole-body scintigraphy and SPECT/CT were performed on the same day in all patients receiving radioiodine therapy. Each radioactive focus at whole-body scintigraphy was classified as positive or equivocal with respect to thyroid bed, lymph node, and distant metastasis uptake. Differences between whole-body scintigraphy and SPECT/CT findings were assessed with the generalized McNemar test. Results: At SPECT/CT, origin was clearly determined of all five "hot spots" in the thyroid bed (remnant thyroid tissue or metastatic lymph node) that were judged as equivocal at wholebody scintigraphy. Interpretation of 24 (22.2%) of 108 radioactive foci for lymph node metastases was changed with SPECT/CT (P < .0001). One of 85 foci that were thought to be positive findings at whole-body scintigraphy turned out to be a negative finding (false-positive finding), and 13 and seven of 20 equivocal foci at whole-body scintigraphy were positive and negative findings, respectively, after adding SPECT/CT findings. Three false-negative findings at whole-body scintigraphy were corrected with SPECT/CT. For the detection of distant metastasis, the interpretations of 21 (40%) of 52 foci were corrected with SPECT/CT (P < .0001). One of 32 foci thought to be a positive finding at whole-body scintigraphy was a negative finding, and 11 and nine of 20 equivocal foci at whole-body scintigraphy were positive and negative findings, respectively, after SPECT/CT. At a patient-based analysis, SPECT/CT findings helped change the clinical staging in nine (6.1%) of 147 patients and therapeutic planning in three (2.0%) of 147 patients. Conclusion: SPECT/CT improved detection and localization of 131I accumulation in lymph node metastases and distant metastases, compared with whole-body scintigraphy.

DOI： 10.1148/radiol.12112108

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

The aim of this study was to investigate the effects of the pointspread function (PSF) and time-of-flight (TOF) on improving ¹⁸FFDG PET/CT images in relation to reconstruction parameters and noise-equivalent counts (NEC). Methods: This study consisted of a phantom study and a retrospective analysis of 39 consecutive patients who underwent clinical ¹⁸F-FDG PET/CT. The body phantom of the National Electrical Manufacturers Association and International Electrotechnical Commission with a 10-mm-diameter sphere was filled with an ¹⁸F-FDG solution with a 4:1 radioactivity ratio compared with the background. The PET data were reconstructed with the baseline ordered-subsets expectation maximization (OSEM) algorithm, with the OSEM+PSF model, with the OSEM+TOF model, and with the OSEM+PSF+TOF model. We evaluated image quality by visual assessment, the signal-to-noise ratio of the 10-mm sphere (SNR_{10 mm}), the contrast of the 10-mm sphere, and the coefficient of variance in the phantom study and then determined the optimal reconstruction parameters. We also examined the effects of PSF and TOF on the quality of clinical images using the signal-to-noise ratio in the liver (SNR_liver) in relation to the NEC in the liver (ENC_liver). Results: In the phantom study, the SNR_{10 mm} was the highest for the OSEM+PSF+TOF model, and the highest value was obtained at iteration 2 for algorithms with the TOF and at iteration 3 for those without the TOF. In terms of a postsmoothing filter full width at half maximum (FWHM), the high SNR _{10 mm} was obtained with no filtering or was smaller than 2 mm for algorithms with PSF and was 4-6 mm for those without PSF. The balance between the contrast recovery and noise is different for algorithms with either PSF or TOF. A combination of PSF and TOF improved SNR_{10 mm}, contrast, and coefficient of variance, especially with a small-FWHM gaussian filter. In the clinical study, the SNR_liver of the low- ENC_liver group in the OSEM+PSF+TOF model was compared with that of the high-ENC_liver group in conventional OSEM. The PSF+TOF improved the SNR_liver by about 24.9% ± 9.81%. Conclusion: A combination of PSF and TOF clearly improves image quality, whereas optimization of the reconstruction parameters is necessary to obtain the best performance for PSF or TOF. Furthermore, this combination has the potential to provide good image quality with either lower activity or shorter acquisition time, thus improving patient comfort and reducing the radiation burden. COPYRIGHT

DOI： 10.2967/jnumed.112.103861

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

Purpose: To retrospectively determine the incremental diagnostic value of adding single photon emission computed tomography/ computed tomography (SPECT/CT) to whole-body scintigraphy with iodine 131 (¹³¹I) compared with scintigraphy alone after radioiodine therapy in patients with well-differentiated thyroid carcinoma. Materials and Methods: This retrospective study was institutional review board approved; written informed consent was waived. The study included 147 patients (94 female, 53 male patients; mean age, 51 years) with well-differentiated thyroid carcinoma treated with radioiodine therapy between October 2009 and August 2010. Whole-body scintigraphy and SPECT/CT were performed on the same day in all patients receiving radioiodine therapy. Each radioactive focus at whole-body scintigraphy was classified as positive or equivocal with respect to thyroid bed, lymph node, and distant metastasis uptake. Differences between whole-body scintigraphy and SPECT/CT findings were assessed with the generalized McNemar test. Results: At SPECT/CT, origin was clearly determined of all five "hot spots" in the thyroid bed (remnant thyroid tissue or metastatic lymph node) that were judged as equivocal at wholebody scintigraphy. Interpretation of 24 (22.2%) of 108 radioactive foci for lymph node metastases was changed with SPECT/CT (P < .0001). One of 85 foci that were thought to be positive findings at whole-body scintigraphy turned out to be a negative finding (false-positive finding), and 13 and seven of 20 equivocal foci at whole-body scintigraphy were positive and negative findings, respectively, after adding SPECT/CT findings. Three false-negative findings at whole-body scintigraphy were corrected with SPECT/CT. For the detection of distant metastasis, the interpretations of 21 (40%) of 52 foci were corrected with SPECT/CT (P < .0001). One of 32 foci thought to be a positive finding at whole-body scintigraphy was a negative finding, and 11 and nine of 20 equivocal foci at whole-body scintigraphy were positive and negative findings, respectively, after SPECT/CT. At a patient-based analysis, SPECT/CT findings helped change the clinical staging in nine (6.1%) of 147 patients and therapeutic planning in three (2.0%) of 147 patients. Conclusion: SPECT/CT improved detection and localization of 131I accumulation in lymph node metastases and distant metastases, compared with whole-body scintigraphy.

DOI： 10.1148/radiol.12112108

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

Purpose We developed a method for predicting truenegative lymph node metastases in clinical IA non-small lung cancer (NSCLC) by the combined evaluation of computed tomography (CT), 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) findings and the maximum standardized uptake value (SUVmax) of primary tumors. Methods The subjects of this study were 94 patients with clinical stage IA NSCLC who underwent both preoperative CT and FDG-PET. We analyzed the relationship between the SUVmax of primary tumors and various clinicopathological factors to find the best method available for assessing true-negative lymph node metastasis. Results The pathological stages were IA (n = 80), IB (n = 4), IIA (n = 5), IIIA (n = 4), and IV (n = 1). Pathologic lymph node metastasis was recognized in nine patients and the SUVmax of these tumors ranged from 3.3 to 20.3. A SUVmax of 3.0 was defined as the cut-off point and patients were dichotomized according to this point. Tumors with SUVmax of 3.0 or less were associated with a significantly lower incidence of pleural and vascular invasion and were characterized by the degree of differentiation. Conclusion The SUVmax of primary tumors reflects the grade of malignancy; therefore, the combined evaluation of FDG-PET/CT findings with the SUVmax of primary tumors may help predict lymph node metastasis negativity.

DOI： 10.1007/s00595-012-0277-7

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

Purpose We developed a method for predicting truenegative lymph node metastases in clinical IA non-small lung cancer (NSCLC) by the combined evaluation of computed tomography (CT), 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) findings and the maximum standardized uptake value (SUVmax) of primary tumors. Methods The subjects of this study were 94 patients with clinical stage IA NSCLC who underwent both preoperative CT and FDG-PET. We analyzed the relationship between the SUVmax of primary tumors and various clinicopathological factors to find the best method available for assessing true-negative lymph node metastasis. Results The pathological stages were IA (n = 80), IB (n = 4), IIA (n = 5), IIIA (n = 4), and IV (n = 1). Pathologic lymph node metastasis was recognized in nine patients and the SUVmax of these tumors ranged from 3.3 to 20.3. A SUVmax of 3.0 was defined as the cut-off point and patients were dichotomized according to this point. Tumors with SUVmax of 3.0 or less were associated with a significantly lower incidence of pleural and vascular invasion and were characterized by the degree of differentiation. Conclusion The SUVmax of primary tumors reflects the grade of malignancy; therefore, the combined evaluation of FDG-PET/CT findings with the SUVmax of primary tumors may help predict lymph node metastasis negativity.

DOI： 10.1007/s00595-012-0277-7

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

ABSTRACT: Acquired perforating dermatosis (APD) is an uncommon cutaneous perforating disorder. We report a patient on hemodialysis who developed skin eruption and jaundice. He underwent FDG PET/CT under suspicion of biliary malignancies. PET/CT showed no significant abnormal uptake except of multiple FDG-avid nodules in the skin. The eruption he had was histopathologically diagnosed as APD by skin biopsy. His case suggests that APD should be considered as a differential diagnosis when multiple cutaneous FDG accumulations are found in a patient on hemodialysis. To the best of our knowledge, this is the first report showing the FDG PET/CT findings of APD.

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A 26-year-old female who had had a hydatidiform mole at 20 years of age showed high levels of serum human chorionic gonadotropin. Because pelvic ultrasound did not show any gestational sac in her uterus, she was suspected to have had an extrauterine pregnancy and a spontaneous abortion. About 6 months later, a pulmonary nodule in the patient's right upper lung field was found on a routine chest X-ray film. Contrast- enhanced CT scans revealed a solitary lobulated nodule 2.0 × 1.3 × 3.0 cm in diameter in the S2 segment of the right lung. CT suggested a vessel malformation. Positron emission tomography using 2-deoxy-2-[¹⁸F]fluoro-d-glucose (FDG-PET) was performed and showed weak FDG accumulation (SUVmax = 2.0) in the nodule, which did not positively indicate malignancy. Because a follow-up CT showed a rapid increase in the size of the nodule, partial resection of S2 segment in the right upper lobe was performed. The histopathological diagnosis was a metastasis from choriocarcinoma. The tumor consisted largely of necrosis and hemorrhage, and it was considered to be a major cause of the unusual FDG-PET and CT findings.

DOI： 10.1007/s12149-012-0644-x

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

A 26-year-old female who had had a hydatidiform mole at 20 years of age showed high levels of serum human chorionic gonadotropin. Because pelvic ultrasound did not show any gestational sac in her uterus, she was suspected to have had an extrauterine pregnancy and a spontaneous abortion. About 6 months later, a pulmonary nodule in the patient's right upper lung field was found on a routine chest X-ray film. Contrast- enhanced CT scans revealed a solitary lobulated nodule 2.0 × 1.3 × 3.0 cm in diameter in the S2 segment of the right lung. CT suggested a vessel malformation. Positron emission tomography using 2-deoxy-2-[¹⁸F]fluoro-d-glucose (FDG-PET) was performed and showed weak FDG accumulation (SUVmax = 2.0) in the nodule, which did not positively indicate malignancy. Because a follow-up CT showed a rapid increase in the size of the nodule, partial resection of S2 segment in the right upper lobe was performed. The histopathological diagnosis was a metastasis from choriocarcinoma. The tumor consisted largely of necrosis and hemorrhage, and it was considered to be a major cause of the unusual FDG-PET and CT findings.

DOI： 10.1007/s12149-012-0644-x

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

We evaluated the feasibility of 256-slice MDCT for detecting coronary artery stenosis without beta blocker premedication, and assessed the diagnostic accuracy of MDCT for detecting myocardial ischemia by ²⁰¹Tl SPECT. Fifty-three patients underwent both coronary CT angiography and stress myocardial perfusion SPECT. All coronary arteries were assessable with appropriate image quality. MDCT revealed high specificity, but only half of stenotic lesion by MDCT revealed ischemia on SPECT.

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

We evaluated the feasibility of 256-slice MDCT for detecting coronary artery stenosis without beta blocker premedication, and assessed the diagnostic accuracy of MDCT for detecting myocardial ischemia by ²⁰¹Tl SPECT. Fifty-three patients underwent both coronary CT angiography and stress myocardial perfusion SPECT. All coronary arteries were assessable with appropriate image quality. MDCT revealed high specificity, but only half of stenotic lesion by MDCT revealed ischemia on SPECT.

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

ABSTRACT: Acquired perforating dermatosis (APD) is an uncommon cutaneous perforating disorder. We report a patient on hemodialysis who developed skin eruption and jaundice. He underwent FDG PET/CT under suspicion of biliary malignancies. PET/CT showed no significant abnormal uptake except of multiple FDG-avid nodules in the skin. The eruption he had was histopathologically diagnosed as APD by skin biopsy. His case suggests that APD should be considered as a differential diagnosis when multiple cutaneous FDG accumulations are found in a patient on hemodialysis. To the best of our knowledge, this is the first report showing the FDG PET/CT findings of APD.

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

Objective: The aim of this study was to determine the optimal acquisition scan protocol for deep inspiration breath-hold (BH) fluoro-2-deoxy-D-glucose positron emission tomography (PET) for the examination of thoracic lesions. Methods: We studied 32 thoracic lesions in 21 patients. Whole-body PET/computed tomography (CT) scanning with free breathing (FB) was performed for 3 min per bed position, followed by a BH-CT and five BH-PET for 20 s each. Summed BH images with total acquisition times of 40, 60, 80 and 100 s were generated (BH×2, BH×3, BH×4 and BH×5, respectively). The displacements between PET and CT images, the lesion volume of the PET image, the maximum standardized uptake value (SUV_max) and the quality of the PET image were assessed in relation to the clinical characteristics of each patient and the summation of the BH-PET images. Results: BH-PET decreased the tumor volume significantly (FB: 7.23±9.70 cm³, BH×5: 4.71±5.14 cm³, P<0.01) and increased the SUV_max (FB: 6.27±5.41, BH×5: 7.53±6.28, P<0.01). The displacement between the PET and CT images was improved significantly in the BH scans (FB: 0.77±0.53 cm, BH×5: 0.36±0.24 cm, P<0.01). In addition, aging and lung function of patients influenced the reproducibility of BH-PET. The summed BH-PET images, obtained by summation of three or more BH-PET images (total acquisition time of 60 s or more), achieved good image quality. Conclusion: BH-PET/CT improved the misregistration between PET and CT images and increased the SUV_max of thoracic lesions. The recommended number of BH-PET images for summation with 20 s of acquisition time is three or more.

DOI： 10.1097/MNM.0b013e32834bbda7

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

Since the introduction of ⁶⁷Gallium-citrate 30 years ago, nuclear medicine has played an important role in the evaluation of malignant lymphoma. During that time, several radiotracers were evaluated as potential alternatives for the diagnosis of lymphoma, but the introduction of ¹⁸F-fluorodeoxyglucose PET (FDG-PET) marked a major turning point. FDG-PET took over most of the role of gallium, and is now an essential tool in the diagnosis of lymphoma. FDG-PET is increasingly being used for assessment of the tumor staging prior to treatment, for evaluating the response to treatment, and for monitoring the early reactions to therapy to predict the final outcome. FDG-PET has been shown to have more accurate diagnostic capability than conventional CT and MRI for distinguishing the tumor necrosis and residual masses frequently seen after therapy in lymphoma patients without any clinical and biochemical manifestation. Malignant lymphoma is the first disease for which FDG-PET was adopted as a tool for response assessment in the international standard criteria. However, lymphoma does not always display a clear high uptake, and there are some pitfalls in assessing the response to therapy. This review will highlight the most important applications of FDG-PET in lymphoma, focusing on the advantages and pitfalls of this imaging, and past and ongoing efforts to standardize the use of FDG-PET, particularly in response to assessment and therapy monitoring.

DOI： 10.1007/s12149-011-0549-0

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

Objective: The aim of this study was to determine the optimal acquisition scan protocol for deep inspiration breath-hold (BH) fluoro-2-deoxy-D-glucose positron emission tomography (PET) for the examination of thoracic lesions. Methods: We studied 32 thoracic lesions in 21 patients. Whole-body PET/computed tomography (CT) scanning with free breathing (FB) was performed for 3 min per bed position, followed by a BH-CT and five BH-PET for 20 s each. Summed BH images with total acquisition times of 40, 60, 80 and 100 s were generated (BH×2, BH×3, BH×4 and BH×5, respectively). The displacements between PET and CT images, the lesion volume of the PET image, the maximum standardized uptake value (SUV_max) and the quality of the PET image were assessed in relation to the clinical characteristics of each patient and the summation of the BH-PET images. Results: BH-PET decreased the tumor volume significantly (FB: 7.23±9.70 cm³, BH×5: 4.71±5.14 cm³, P<0.01) and increased the SUV_max (FB: 6.27±5.41, BH×5: 7.53±6.28, P<0.01). The displacement between the PET and CT images was improved significantly in the BH scans (FB: 0.77±0.53 cm, BH×5: 0.36±0.24 cm, P<0.01). In addition, aging and lung function of patients influenced the reproducibility of BH-PET. The summed BH-PET images, obtained by summation of three or more BH-PET images (total acquisition time of 60 s or more), achieved good image quality. Conclusion: BH-PET/CT improved the misregistration between PET and CT images and increased the SUV_max of thoracic lesions. The recommended number of BH-PET images for summation with 20 s of acquisition time is three or more.

DOI： 10.1097/MNM.0b013e32834bbda7

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

Since the introduction of ⁶⁷Gallium-citrate 30 years ago, nuclear medicine has played an important role in the evaluation of malignant lymphoma. During that time, several radiotracers were evaluated as potential alternatives for the diagnosis of lymphoma, but the introduction of ¹⁸F-fluorodeoxyglucose PET (FDG-PET) marked a major turning point. FDG-PET took over most of the role of gallium, and is now an essential tool in the diagnosis of lymphoma. FDG-PET is increasingly being used for assessment of the tumor staging prior to treatment, for evaluating the response to treatment, and for monitoring the early reactions to therapy to predict the final outcome. FDG-PET has been shown to have more accurate diagnostic capability than conventional CT and MRI for distinguishing the tumor necrosis and residual masses frequently seen after therapy in lymphoma patients without any clinical and biochemical manifestation. Malignant lymphoma is the first disease for which FDG-PET was adopted as a tool for response assessment in the international standard criteria. However, lymphoma does not always display a clear high uptake, and there are some pitfalls in assessing the response to therapy. This review will highlight the most important applications of FDG-PET in lymphoma, focusing on the advantages and pitfalls of this imaging, and past and ongoing efforts to standardize the use of FDG-PET, particularly in response to assessment and therapy monitoring.

DOI： 10.1007/s12149-011-0549-0

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

Objective: We evaluated the partial volume effect in PET/CT images and developed a simple correction method to address this problem. Methods: Six spheres and the background in the phantom were filled with F-18 and we thus obtained 4 different sphere-to-background (SB) ratios. Thirty-nine cervical lymph nodes in 7 patients with papillary thyroid carcinoma (15 malignant and 24 benign) were also examined as a preliminary clinical study. First, we developed recovery coefficient (RC) curves normalized to the maximum counts of the 37-mm sphere. Next, we developed a correction table to determine the true SB ratio using three parameters, including the maximum counts of both the sphere and background and the lesion diameter, by modifying the approximation formula of the RC curves including the point-spread function correction. The full width at half maximum in this formula is estimated with the function of the SB ratio. Results: In the phantom study, a size-dependent underestimation of the radioactivity was observed. The degree of decline of RC was influenced by the SB ratio. In preliminary clinical examination, the difference in the SUV _max between malignant and benign LNs thus became more prominent after the correction. The PV correction slightly improved the diagnostic accuracy from 95 to 100%. Conclusions: We developed a simple table lookup correction method for the partial volume effect of PET/CT. This new method is considered to be clinically useful for the diagnosis of cervical LN metastasis. Further examination with a greater number of subjects is required to corroborate its clinical usefulness.

DOI： 10.1007/s12149-010-0401-y

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

Objective: We evaluated the partial volume effect in PET/CT images and developed a simple correction method to address this problem. Methods: Six spheres and the background in the phantom were filled with F-18 and we thus obtained 4 different sphere-to-background (SB) ratios. Thirty-nine cervical lymph nodes in 7 patients with papillary thyroid carcinoma (15 malignant and 24 benign) were also examined as a preliminary clinical study. First, we developed recovery coefficient (RC) curves normalized to the maximum counts of the 37-mm sphere. Next, we developed a correction table to determine the true SB ratio using three parameters, including the maximum counts of both the sphere and background and the lesion diameter, by modifying the approximation formula of the RC curves including the point-spread function correction. The full width at half maximum in this formula is estimated with the function of the SB ratio. Results: In the phantom study, a size-dependent underestimation of the radioactivity was observed. The degree of decline of RC was influenced by the SB ratio. In preliminary clinical examination, the difference in the SUV _max between malignant and benign LNs thus became more prominent after the correction. The PV correction slightly improved the diagnostic accuracy from 95 to 100%. Conclusions: We developed a simple table lookup correction method for the partial volume effect of PET/CT. This new method is considered to be clinically useful for the diagnosis of cervical LN metastasis. Further examination with a greater number of subjects is required to corroborate its clinical usefulness.

DOI： 10.1007/s12149-010-0401-y

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

Brown adipose tissue (BAT) densities assessed as CT Hounsfield units (HUs) were evaluated in a rodent model and in patients to determine whether HUs changed in relation to BAT activity. Methods: Serial ¹⁸F-FDG PET/CT was performed on rats under both room temperature control conditions and after 4 h of cold-stimulation, which is known to activate BAT. The maximum standardized uptake values and CT HUs of BAT were measured, and tissues were examined in the laboratory. Image records from cancer patients who underwent PET/CT were reviewed, and 23 patients were identified who displayed both high and low ¹⁸F-FDG uptake into BAT on serial ¹⁸F-FDG PET/CT scans. The maximum standardized uptake values and CT HUs of BAT were compared in these scans. Results: The mean (±SD) CT HUs of cold-activated BAT (-12.4 ± 22.4) were significantly higher than those (-27.9 ± 9.6) of the controls in the rat model. The CT HUs of BAT (-71.6 ± 18.0) in the patients with high ¹⁸F-FDG uptake were significantly higher than those (-104.4 ± 16.8) of the patients with low ¹⁸F-FDG uptake . A decrease in relative lipid content is seen in activated BAT in rats on histology. Conclusion: The CT HUs of BAT increased in activated conditions in both animals and patients, likely because of lipid consumption by activated BAT.

DOI： 10.2967/jnumed.109.068775

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

Background: If the sentinel-lymph-node (SLN) concept is valid in cervical cancer, most patients could avoid pelvic lymphadenectomy when absence of metastasis is intraoperatively confirmed in the SLN. We assessed feasibility and accuracy of SLN detection using ^99mTc phytate in patients with cervical cancer. Methods: Eighty-two women with stage Ia-IIb cervical cancer enrolled in this study. All underwent hysterectomy or trachelectomy with accompanying total pelvic lymphadenectomy. On the day before surgery, we injected fluid containing ^99mTc-labeled phytate subepithelially into four cervical quadrants outside the tumor. Intraoperatively, SLNs were identified as radioactive "hot nodes" by gamma probe. Systematic bilateral pelvic lymphadenectomy was performed after the hot node sampling to evaluate the predictive ability of hot nodes. Results: A total of 157 lymph nodes were detected as SLNs in 72 of 82 patients. SLN detection rate was 88%. Detection rate was 95% for the subgroups of patients with stage Ia-Ib1 disease and smaller tumor size (≤3 cm in maximal diameter). Lymph node metastasis was found in 15 patients. In 3 of them, no SLNs were detected. In the remaining 12 patients, each ipsilateral SLN contained metastasis when the pelvic lymph nodes contained metastases. Sensitivity was 100%, the false negative rate was 0%, and the negative predictive value of SLN was 100%. Conclusion: We conclude SLN detection using ^99mTc-labeled phytate is satisfactory to assess pelvic nodes in patients with early cervical cancer; if validated with other research, it should be incorporated into clinical practice.

DOI： 10.1007/s10147-009-0010-8

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

Objective: The aim of this study was to clarify the predictive significance of nodal calcification in terms of the therapeutic option of ¹³¹I therapy in papillary thyroid carcinoma (PTC) patients. Methods: We reviewed 19 computed tomography (CT) examinations of PTC patients on receiving ¹³¹I therapy for the presence of nodal calcification, and compared the ¹³¹I whole-body scintigraphy and ¹⁸F-2-fluoro-2-deoxy- D-glucose (FDG) positron emission tomography (PET)/CT findings. The metastatic lymph nodes (mLNs) were divided into three groups: A, those with calcification; B, those without calcification but belonging to patients who had calcified mLNs; C, those without calcification and belonging to patients who had no calcified mLNs. The incidences of ¹³¹I accumulation and maximum standardised uptake values (SUV max) in the three groups were compared. Results: A total of 70 mLNs were evaluated. Twelve mLNs belonged to group A, 13 to group B and 45 to group C. The incidences of ¹³¹I accumulation were significantly higher in groups A (100%) and B (100%) than in group C (11.1%) (p<0.0001 for both). The SUVmax was significantly lower in groups A (4.1±1.9) and B (3.9±1.4) than in group C (7.1±4.4) (p=0.01, p=0.002, respectively). Conclusions: Our results indicated that calcification in mLNs related to the ability of ¹³¹I accumulation and less dedifferentiation.

DOI： 10.1007/s00330-009-1557-5

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

Objective: The aims of this retrospective study were to evaluate the incidence of residual lymph node (LN) metastases in high-risk papillary thyroid cancer (PTC) patients receiving adjuvant I-131 therapy, especially in those without I-131 accumulation, and to evaluate the clinical usefulness of F-18 FDG PET/CT to detect those lesions. Methods: The 37 PTC patients receiving adjuvant I-131 therapy were retrospectively evaluated. We examined the incidence of residual LN metastasis and compared the accumulation of F-18 FDG and I-131 in those lesions, and compared the serum thyroglobulin (Tg) levels between patients with and without residual LN metastases. Result: A total of 33 lesions were diagnosed as residual LN metastases in 9 patients. FDG accumulated in all of the lesions, but 19 lesions (57.6%) of them had no I-131 accumulation. The SUVmax was significantly higher in lesions without I-131 accumulation than in lesions with I-131 accumulation (6.6 ± 2.8 vs. 4.2 ± 1.8; P = 0.007). The serum Tg levels were significantly higher in patients with residual LN metastases than in patients without it (709.9 ± 1470.8 vs. 25.6 ± 37.1 ng/mL; P = 0.005). The incidence of residual LN metastasis was significantly higher in patients with a detectable serum Tg level than in patients without it (35.0% vs. 0%, P = 0.03). Conclusion: These results indicate that the residual LN metastasis was relatively common in high-risk PTC patients receiving adjuvant I-131 therapy whose serum Tg levels remained detectable, and those lesions often had no I-131 accumulation. FDG-PET/CT would be recommended for PTC patients with detectable serum Tg levels to detect residual LN metastases.

DOI： 10.1097/RLU.0b013e3181c3b737

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

Our goal was to estimate and compare across different readers the reproducibility of the ¹⁸F-FDG PET standardized uptake value (SUV) and CT size measurements, and changes in those measurements, in malignant tumors before and after therapy. Methods: Fifty-two tumors in 25 patients were evaluated on ¹⁸F-FDG PET/CT scans. Maximum SUVs (SUV_bw max) and CT size measurements were determined for each tumor independently on pre- and posttreatment scans by 8 different readers (4 PET, 4 CT) using routine nonautomated clinical methods. Percentage changes in SUV_bw max and CT size between pre- and posttreatment scans were calculated. Interobserver reproducibility of SUV_bw max, CT size, and changes in these values were described by intraclass correlation coefficients (ICCs) and estimates of variance. Results: The ICC was higher for the pretreatment, posttreatment, and percentage change in SUV_bw max than the ICC for the longest CT size and the 2-dimensional CT size (before treatment, 0.93, 0.72, and 0.61, respectively; after treatment, 0.91, 0.85, and 0.45, respectively; and percentage change, 0.94, 0.70, and 0.33, respectively). The variability of SUV_bw max was significantly lower than the variability of the longest CT size and the 2-dimensional CT size (mean ± SD before treatment, 6.3% ± 14.2%, 16.2% ± 17.8%, and 27.5% ± 26.7%, respectively, P ≤ 0.001; and after treatment, 18.4% ± 26.8%, 35.1% ± 47.5%, and 50.9% ± 51.4%, respectively, P ≤ 0.02). The variability of percentage change in SUV_bw max (16.7% ± 36.2%) was significantly lower than that for percentage change in the longest CT size (156.3% ± 157.3%, P ≤ 0.0001) and the 2-dimensional CT size (178.4% ± 546.5%, P < 0.0001). Conclusion: The interobserver reproducibility of SUV_bw max for both untreated and treated tumors and percentage change in SUV_bw max are substantially higher than measurements of CT size and percentage change in CT size. Measurements of tumor metabolism by PET should be included in trials to assess response to therapy. Although PET reproducibility was high, the variability observed in analyses of identical image sets by 4 readers indicates that automated analytic tools to assess response might be helpful to further enhance reproducibility.

DOI： 10.2967/jnumed.109.063321

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

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

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

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

Pulmonary tumor thrombotic microangiopathy (PTTM) is his- topathologically characterized by proliferation of intimal myofibroblasts in the small pulmonary arterioles, induced by tumor microemboli. Patients develop rapidly progressive and severe cardiopulmonary failure, and the clinical course of this disease is fatal. Conventional radiologic findings are often minimal or nonspecific, making diagnosis difficult before death. We report 2-(F-18)-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) images of PTTM, which illustrate the characteristic findings of this clinical entity. FDG-PET can be helpful for the diagnosis of PTTM.

DOI： 10.1097/RLU.0b013e3181966f5c

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

Purpose: The aim of this study was to address the efficacy of 2-[F-18]-Fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) in the staging of non-small cell lung cancer (NSCLC) and in prognostic prediction in patients with NSCLC. Methods: Forty-four patients (26 males, 18 females) were analyzed. Results: Accurate staging was obtained by addition of FDG-PET. Multivariate analysis indicated that the standardized uptake value of the primary tumor was the most significant prognostic factor for disease-free survival (P=.0073). Conclusion: FDG-PET is useful for the diagnosis of NSCLC and for prognostic prediction in patients with NSCLC.

DOI： 10.1016/j.clinimag.2008.06.032

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

Pulmonary tumor thrombotic microangiopathy (PTTM) is his- topathologically characterized by proliferation of intimal myofibroblasts in the small pulmonary arterioles, induced by tumor microemboli. Patients develop rapidly progressive and severe cardiopulmonary failure, and the clinical course of this disease is fatal. Conventional radiologic findings are often minimal or nonspecific, making diagnosis difficult before death. We report 2-(F-18)-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) images of PTTM, which illustrate the characteristic findings of this clinical entity. FDG-PET can be helpful for the diagnosis of PTTM.

DOI： 10.1097/RLU.0b013e3181966f5c

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

Purpose: The aim of this study was to address the efficacy of 2-[F-18]-Fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) in the staging of non-small cell lung cancer (NSCLC) and in prognostic prediction in patients with NSCLC. Methods: Forty-four patients (26 males, 18 females) were analyzed. Results: Accurate staging was obtained by addition of FDG-PET. Multivariate analysis indicated that the standardized uptake value of the primary tumor was the most significant prognostic factor for disease-free survival (P=.0073). Conclusion: FDG-PET is useful for the diagnosis of NSCLC and for prognostic prediction in patients with NSCLC.

DOI： 10.1016/j.clinimag.2008.06.032

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

Pulmonary tumor thrombotic microangiopathy (PTTM) is his- topathologically characterized by proliferation of intimal myofibroblasts in the small pulmonary arterioles, induced by tumor microemboli. Patients develop rapidly progressive and severe cardiopulmonary failure, and the clinical course of this disease is fatal. Conventional radiologic findings are often minimal or nonspecific, making diagnosis difficult before death. We report 2-(F-18)-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) images of PTTM, which illustrate the characteristic findings of this clinical entity. FDG-PET can be helpful for the diagnosis of PTTM.

DOI： 10.1097/RLU.0b013e3181966f5c

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

Purpose: The aim of this study was to address the efficacy of 2-[F-18]-Fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) in the staging of non-small cell lung cancer (NSCLC) and in prognostic prediction in patients with NSCLC. Methods: Forty-four patients (26 males, 18 females) were analyzed. Results: Accurate staging was obtained by addition of FDG-PET. Multivariate analysis indicated that the standardized uptake value of the primary tumor was the most significant prognostic factor for disease-free survival (P=.0073). Conclusion: FDG-PET is useful for the diagnosis of NSCLC and for prognostic prediction in patients with NSCLC.

DOI： 10.1016/j.clinimag.2008.06.032

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

Our objective was to determine whether multiple clinically useful radiotracers accumulate in brown adipose tissue (BAT) and to assess their uptake in rats kept at room temperature or exposed to a cold environment. Methods: The following radiotracers were injected intravenously into groups of 6 female Wistar rats: ²⁰¹Tl-chloride (TlCl), ¹²³I- metaiodobenzylguanidine (MIBG), ^99mTc-sestamibi (MIBI), ¹⁸F- or ³H-FDG, ³H-L-methionine, and ³H-thymidine. BAT-stimulated animals were maintained at 4°C for 4 h before tracer injection, whereas control animals were kept at approximately 22.5°C. The animals were sacrificed at 20-60 min after tracer injection, and BAT, major organs, and blood were extracted, weighed, and measured for radioactivity. The localization of uncoupling protein-1, glucose transporter-1, and norepinephrine transporter was evaluated with immunohistochemical staining in both groups. Results: We determined the percentage injected dose (%ID) per gram of each radiotracer in interscapular BAT, normalized to blood %ID/g. In control animals, this uptake ratio (6SD) was 8.44 ± 3.39 for ²⁰¹TlCl, 9.77 ± 6.06 for ¹²³IMIBG, 37.30 ± 14.42 for ^99mTc-MIBI, 5.47 ± 4.44 for ¹⁸F- or ³H-FDG, 1.93 ± 0.87 for ³H-L-methionine, and 1.22 ± 0.74 for ³Hthymidine. Compared with uptake at room temperature, uptake after exposure to cold increased 26.4-fold (P < 0.01) for ¹⁸F- or ³H-FDG and increased significantly (P < 0.05) for ²⁰¹Tl (2.04-fold), ¹²³I-MIBG (3.25-fold), and ³H-L-methionine (3.11-fold). Immunohistochemical staining revealed increased glucose transporter-1 and norepinephrine transporter expression in BAT cell membranes and blood vessels after exposure to cold, whereas uncoupling protein-1 was expressed in the cytoplasm under both control and cold-stimulated conditions. Conclusion: BAT uptake of ¹⁸F- or ³H-FDG, ¹²³I-MIBG, and ³H-L-methionine was significantly increased over the control state by exposure to cold. Increased uptake of ²⁰¹TlCl relative to blood in cold-stimulated BAT suggests that blood flow in BAT is increased by exposure to cold. The greater increased uptake with ¹⁸F- or ³H-FDG, ¹²³I-MIBG, and ³H-L-methionine, and the immunohistostaining findings, suggest that other factors in addition to blood flow (e.g., increased metabolism, increased transport, or metabolic trapping of the tracers) are involved in cold-stimulated BAT activation. Knowledge that high uptake in BAT may possibly be observed on clinical scans using several radiotracers, especially after patients are exposed to the cold, may lead to more accurate interpretation of clinical studies.

DOI： 10.2967/jnumed.107.041715

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

Our objective was to determine whether multiple clinically useful radiotracers accumulate in brown adipose tissue (BAT) and to assess their uptake in rats kept at room temperature or exposed to a cold environment. Methods: The following radiotracers were injected intravenously into groups of 6 female Wistar rats: ²⁰¹Tl-chloride (TlCl), ¹²³I- metaiodobenzylguanidine (MIBG), ^99mTc-sestamibi (MIBI), ¹⁸F- or ³H-FDG, ³H-L-methionine, and ³H-thymidine. BAT-stimulated animals were maintained at 4°C for 4 h before tracer injection, whereas control animals were kept at approximately 22.5°C. The animals were sacrificed at 20-60 min after tracer injection, and BAT, major organs, and blood were extracted, weighed, and measured for radioactivity. The localization of uncoupling protein-1, glucose transporter-1, and norepinephrine transporter was evaluated with immunohistochemical staining in both groups. Results: We determined the percentage injected dose (%ID) per gram of each radiotracer in interscapular BAT, normalized to blood %ID/g. In control animals, this uptake ratio (6SD) was 8.44 ± 3.39 for ²⁰¹TlCl, 9.77 ± 6.06 for ¹²³IMIBG, 37.30 ± 14.42 for ^99mTc-MIBI, 5.47 ± 4.44 for ¹⁸F- or ³H-FDG, 1.93 ± 0.87 for ³H-L-methionine, and 1.22 ± 0.74 for ³Hthymidine. Compared with uptake at room temperature, uptake after exposure to cold increased 26.4-fold (P < 0.01) for ¹⁸F- or ³H-FDG and increased significantly (P < 0.05) for ²⁰¹Tl (2.04-fold), ¹²³I-MIBG (3.25-fold), and ³H-L-methionine (3.11-fold). Immunohistochemical staining revealed increased glucose transporter-1 and norepinephrine transporter expression in BAT cell membranes and blood vessels after exposure to cold, whereas uncoupling protein-1 was expressed in the cytoplasm under both control and cold-stimulated conditions. Conclusion: BAT uptake of ¹⁸F- or ³H-FDG, ¹²³I-MIBG, and ³H-L-methionine was significantly increased over the control state by exposure to cold. Increased uptake of ²⁰¹TlCl relative to blood in cold-stimulated BAT suggests that blood flow in BAT is increased by exposure to cold. The greater increased uptake with ¹⁸F- or ³H-FDG, ¹²³I-MIBG, and ³H-L-methionine, and the immunohistostaining findings, suggest that other factors in addition to blood flow (e.g., increased metabolism, increased transport, or metabolic trapping of the tracers) are involved in cold-stimulated BAT activation. Knowledge that high uptake in BAT may possibly be observed on clinical scans using several radiotracers, especially after patients are exposed to the cold, may lead to more accurate interpretation of clinical studies.

DOI： 10.2967/jnumed.107.041715

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

To determine the most robust and reproducible parameters for noninvasively estimating tumor cell burden in a murine model, we used real-time in vivo bioluminescent imaging to assess the growth kinetics and dissemination of luciferase-transfected Raji B-cell lymphoma. Bioluminescent signals were acquired every minute for 40 minutes after luciferin injection every other day post-tumor injection. The total 40-minute area under the curve (AUC) of photon intensity (photons/second) was calculated and compared with simplified fixed time point observations (every 5 minutes from 5 to 40 minutes after substrate injection). There was substantial variability in the shape of the time signal intensity curves at different stages of tumor growth in both the intravenous and subcutaneous models. The coefficient of variance in the AUC was 0.27 (intravenous) and 0.36 (subcutaneous) as values determined by fitting the curve, whereas the 20-minute time point measurement varied at 0.29 (intravenous) and 0.37 (subcutaneous). In both the subcutaneous and intravenous models, single time point measurements at 20 minutes had the highest correlation value with AUC. This simplified single time point measurement appears appropriate to estimate the total tumor burden in this model, but the substantial variance at each measurement must be considered in experimental designs.

DOI： 10.2310/7290.2007.00031

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

To determine the most robust and reproducible parameters for noninvasively estimating tumor cell burden in a murine model, we used real-time in vivo bioluminescent imaging to assess the growth kinetics and dissemination of luciferase-transfected Raji B-cell lymphoma. Bioluminescent signals were acquired every minute for 40 minutes after luciferin injection every other day post-tumor injection. The total 40-minute area under the curve (AUC) of photon intensity (photons/second) was calculated and compared with simplified fixed time point observations (every 5 minutes from 5 to 40 minutes after substrate injection). There was substantial variability in the shape of the time signal intensity curves at different stages of tumor growth in both the intravenous and subcutaneous models. The coefficient of variance in the AUC was 0.27 (intravenous) and 0.36 (subcutaneous) as values determined by fitting the curve, whereas the 20-minute time point measurement varied at 0.29 (intravenous) and 0.37 (subcutaneous). In both the subcutaneous and intravenous models, single time point measurements at 20 minutes had the highest correlation value with AUC. This simplified single time point measurement appears appropriate to estimate the total tumor burden in this model, but the substantial variance at each measurement must be considered in experimental designs.

DOI： 10.2310/7290.2007.00031

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

This study evaluated the effect of various β-adrenergic agonists on ¹⁸F-FDG uptake in brown adipose tissue (BAT) in rats using ex vivo biodistribution studies. Methods: Caffeine (10 mg/kg of body weight, n = 4), ephedrine (5 mg/kg of body weight, n = 4), nicotine (0.8 mg/kg of body weight, n = 9), or a mixture of nicotine and ephedrine (0.8 mg/kg of body weight and 5 mg/kg of body weight, respectively, n = 9) was injected into the peritoneal cavity of female Lewis rats 30 min before intravenous ¹⁸F-FDG injection. One hour after injection of ¹⁸F-FDG, the animals were sacrificed, and BAT, other major organs, and blood were extracted. The biodistribution results were compared with body temperature data. Results: In the rats injected with nicotine or ephedrine, the mean uptake of ¹⁸F-FDG, in percentage injected dose (%ID)/(g of interscapular BAT) x (kg of body weight), was significantly increased (7.9-fold for nicotine and 3.7-fold for ephedrine), compared to the control rats. Nicotine had the strongest effect on ¹⁸F-FDG uptake in BAT. Caffeine increased BAT uptake slightly, but this increase did not reach statistical significance. The combination of nicotine and ephedrine increased the uptake 12.0-fold, compared with control rats; more than either nicotine or ephedrine alone. Uptake of ¹⁸F-FDG in most other major organs did not change significantly. The effect of nicotine was blocked by prior injection of β-adrenergic antagonists. A transient decrease in body temperature was observed in the nicotine-injected group, and this effect was canceled by prior injection of β-adrenergic antagonists. No significant change in baseline temperature was seen before or after β-adrenergic agonist injection. Conclusion: Nicotine caused a greater increase in ¹⁸F-FDG uptake in BAT than did other interventions, and the effect was increased when nicotine was combined with ephedrine. The effect of nicotine was completely blocked by prior injection of β-adrenergic antagonists, indicating that β-adrenergic agonists increase the metabolism of BAT. These preclinical data suggest that patients should avoid nicotine and ephedrine before undergoing ¹⁸F-FDG PET to minimize ¹⁸F-FDG uptake in BAT.

DOI： 10.2967/jnumed.106.039065

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

This study evaluated the effect of various β-adrenergic agonists on ¹⁸F-FDG uptake in brown adipose tissue (BAT) in rats using ex vivo biodistribution studies. Methods: Caffeine (10 mg/kg of body weight, n = 4), ephedrine (5 mg/kg of body weight, n = 4), nicotine (0.8 mg/kg of body weight, n = 9), or a mixture of nicotine and ephedrine (0.8 mg/kg of body weight and 5 mg/kg of body weight, respectively, n = 9) was injected into the peritoneal cavity of female Lewis rats 30 min before intravenous ¹⁸F-FDG injection. One hour after injection of ¹⁸F-FDG, the animals were sacrificed, and BAT, other major organs, and blood were extracted. The biodistribution results were compared with body temperature data. Results: In the rats injected with nicotine or ephedrine, the mean uptake of ¹⁸F-FDG, in percentage injected dose (%ID)/(g of interscapular BAT) x (kg of body weight), was significantly increased (7.9-fold for nicotine and 3.7-fold for ephedrine), compared to the control rats. Nicotine had the strongest effect on ¹⁸F-FDG uptake in BAT. Caffeine increased BAT uptake slightly, but this increase did not reach statistical significance. The combination of nicotine and ephedrine increased the uptake 12.0-fold, compared with control rats; more than either nicotine or ephedrine alone. Uptake of ¹⁸F-FDG in most other major organs did not change significantly. The effect of nicotine was blocked by prior injection of β-adrenergic antagonists. A transient decrease in body temperature was observed in the nicotine-injected group, and this effect was canceled by prior injection of β-adrenergic antagonists. No significant change in baseline temperature was seen before or after β-adrenergic agonist injection. Conclusion: Nicotine caused a greater increase in ¹⁸F-FDG uptake in BAT than did other interventions, and the effect was increased when nicotine was combined with ephedrine. The effect of nicotine was completely blocked by prior injection of β-adrenergic antagonists, indicating that β-adrenergic agonists increase the metabolism of BAT. These preclinical data suggest that patients should avoid nicotine and ephedrine before undergoing ¹⁸F-FDG PET to minimize ¹⁸F-FDG uptake in BAT.

DOI： 10.2967/jnumed.106.039065

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

Mutation screening is widely used for molecular diagnostics of inherited disorders. Furthermore, it is anticipated that the present and future identification of genetic risk factors for complex disorders will increase the need for high-throughput mutation screening technologies. Capillary array electrophoresis (CAE) SSCP analysis is a low-cost, automated method with a high throughput and high reproducibility. Thus, the method fulfills many of the demands to be met for application in routine molecular diagnostics. However, the need for performing the electrophoresis at three temperatures between 18°C and 35°C for achievement of high sensitivity is a disadvantage of the method. Using a panel of 185 mutant samples, we have analyzed the effect of sample purification, sample medium and separation matrix on the sensitivity of CAE-SSCP analysis to optimize the method for molecular diagnostic use. We observed different effects from sample purification and sample medium at different electrophoresis temperatures, probably reflecting the complex interplay between sequence composition, electrophoresis conditions and sensitivity in SSCP analysis. The effect on assay sensitivity from three different polymers was tested using a single electrophoresis temperature of 27°C. The data suggest that a sensitivity of 98-99% can be obtained using a 10% long chain poly-N,N-dimethylacrylamide polymer.

DOI： 10.1002/elps.200600095

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

Mutation screening is widely used for molecular diagnostics of inherited disorders. Furthermore, it is anticipated that the present and future identification of genetic risk factors for complex disorders will increase the need for high-throughput mutation screening technologies. Capillary array electrophoresis (CAE) SSCP analysis is a low-cost, automated method with a high throughput and high reproducibility. Thus, the method fulfills many of the demands to be met for application in routine molecular diagnostics. However, the need for performing the electrophoresis at three temperatures between 18°C and 35°C for achievement of high sensitivity is a disadvantage of the method. Using a panel of 185 mutant samples, we have analyzed the effect of sample purification, sample medium and separation matrix on the sensitivity of CAE-SSCP analysis to optimize the method for molecular diagnostic use. We observed different effects from sample purification and sample medium at different electrophoresis temperatures, probably reflecting the complex interplay between sequence composition, electrophoresis conditions and sensitivity in SSCP analysis. The effect on assay sensitivity from three different polymers was tested using a single electrophoresis temperature of 27°C. The data suggest that a sensitivity of 98-99% can be obtained using a 10% long chain poly-N,N-dimethylacrylamide polymer.

DOI： 10.1002/elps.200600095

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

DOI： 10.1007/BF02985050

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

We present a database, dbQSNP (http://qsnp.gen.kyushu-u.ac.jp/), that provides sequence and allele frequency information for single-nucleotide polymorphisms (SNPs) located in the promoter regions of human genes, which were defined by the 5′ ends of full-length cDNA clones. We searched for the SNPs in these regions by sequencing or single-strand conformation polymorphism (SSCP) analysis. The allele frequencies of the identified SNPs in two ethnic groups were quantified by SSCP analyses of pooled DNA samples. The accuracy of our estimation is supported by strong correlations between the frequencies in our data and those in other databases for the same ethnic groups. The frequencies vary considerably between the two ethnic groups studied, suggesting the need for population-based collections and allele frequency determination of SNPs, in, e.g., association studies of diseases. We show profiles of SNP densities that are characteristic of transcription start site regions. A fraction of the SNPs revealed a significantly different allele frequency between the groups, suggesting differential selection of the genes involved.

DOI： 10.1002/humu.20196

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

We present a database, dbQSNP (http://qsnp.gen.kyushu-u.ac.jp/), that provides sequence and allele frequency information for single-nucleotide polymorphisms (SNPs) located in the promoter regions of human genes, which were defined by the 5′ ends of full-length cDNA clones. We searched for the SNPs in these regions by sequencing or single-strand conformation polymorphism (SSCP) analysis. The allele frequencies of the identified SNPs in two ethnic groups were quantified by SSCP analyses of pooled DNA samples. The accuracy of our estimation is supported by strong correlations between the frequencies in our data and those in other databases for the same ethnic groups. The frequencies vary considerably between the two ethnic groups studied, suggesting the need for population-based collections and allele frequency determination of SNPs, in, e.g., association studies of diseases. We show profiles of SNP densities that are characteristic of transcription start site regions. A fraction of the SNPs revealed a significantly different allele frequency between the groups, suggesting differential selection of the genes involved.

DOI： 10.1002/humu.20196

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

DOI： 10.1007/BF02986333

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

Objective: The aim of this study is to clarify the period of extraosseous accumulation of ^99mTc-hydroxymethylenediphosphonate (HMDP) to radiation nephropathy mimicking recurrent or remnant neuroblastoma in the pararenal region. Methods: We reviewed five neuroblastoma and one ganglioneuroblastoma patients (2 boys and 4 girls aged 1-9 years) who underwent ^99mTc-HMDP bone scintigraphies periodically before and after radiation therapy. Results: Increased renal uptake coincident with the radiation port appeared in 5 of 6 patients from O to 3 months (mean 1.7 months), and persisted up to 7 months after the completion of radiotherapy. Renal uptake of ^99mTc-HMDP was gradually decreased, and eventually became accumulation defects in 5 of 6 patients from 6 to 17 months (mean 8.9 months) after radiotherapy. Conclusion: When extraosseous accumulation is found after radiation therapy in neuroblastoma patients, radiation nephropathy would be a candidate in the differential diagnosis besides recurrent or remnant tumor.

DOI： 10.1007/BF02986333

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

Objective: Bone is one of the most common sites of metastasis in breast cancer patients. Although bone scintigraphy is widely used to detect metastatic breast cancer, the usefulness of ¹⁸FDG-PET for detecting bone metastasis has not been clearly evaluated. The purpose of this study was to compare the diagnostic accuracy of ¹⁸FDG-PET with bone scintigraphy in detecting bone metastasis in breast cancer patients. Methods: Forty-four women aged 35 to 81 years (mean, 56 years) with breast cancer were examined in this study. Both ¹⁸FDG-PET and bone scintigraphy were performed for each patient with 0-69 day intervals (mean, 11.5 days). The results of each image interpretation were compared retrospectively. Whole-body bones were classified into 9 anatomical regions. Metastases were confirmed at 45/187 regions in 14 patients by bone biopsy or clinical follow-up including other imaging techniques for a period of at least 6 months afterwards. Results: On a region basis, the sensitivity, specificity, and accuracy of ¹⁸FDG-PET were 84%, 99% and 95%, respectively. Although these results were comparable to those of bone scintigraphy, the combination of ¹⁸FDG-PET and bone scintigraphy improved the sensitivity (98%) and accuracy (97%) of detection. False negative lesions of bone scintigraphy were mostly bone marrow metastases and those of ¹⁸FDG-PET were mostly osteoblastic metastases. ¹⁸FDG-PET was superior to bone scintigraphy in the detection of osteolytic lesions (92% vs. 73%), but inferior in the detection of osteoblastic lesions (74% vs. 95%). Conclusions: This study shows that ¹⁸FDG-PET tends to be superior to bone scintigraphy in the detection of osteolytic lesions, but inferior in the detection of osteoblastic lesions. ¹⁸FDG-PET should play a complementary role in detecting bone metastasis with bone scintigraphy.

DOI： 10.1007/BF02985050

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

DOI： 10.1097/00006231-200411000-00005

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

We evaluated the quantitative accuracy of the post-injection transmission-based segmented attenuation correction (SAC) technique and transmissionless calculated attenuation correction (CAC) technique in both 2D and 3D scanning for the brain, and compared the results with those obtained using the pre-injection transmission-based measured attenuation correction (MAC) technique, which is generally accepted as the ‘gold standard’.

DOI： 10.1097/00006231-200411000-00005

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

We describe a new environment of a single-stranded conformational polymorphism (SSCP) analysis using automated capillary array sequencers (e.g., ABI PRISm® 3100 and 3700). In this environment, electrophoretic conditions, settings for instrument management, and software for data analysis are adjusted for SSCP analysis. Highly reproducible results are obtained with this new system, and fragments with mutations and/or polymorphisms in different capillaries or different runs can be reliably detected. The relative peak heights between alleles are quantitative and reproducible between runs, and so allele frequencies of single nucleotide polymorphisms can be accurately estimated by a pooled DNA strategy. The method allows unattended, low-cost, and quantitative SSCP analysis using instruments that are widely accessible.

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

We describe a new environment of a single-stranded conformational polymorphism (SSCP) analysis using automated capillary array sequencers (e.g., ABI PRISm® 3100 and 3700). In this environment, electrophoretic conditions, settings for instrument management, and software for data analysis are adjusted for SSCP analysis. Highly reproducible results are obtained with this new system, and fragments with mutations and/or polymorphisms in different capillaries or different runs can be reliably detected. The relative peak heights between alleles are quantitative and reproducible between runs, and so allele frequencies of single nucleotide polymorphisms can be accurately estimated by a pooled DNA strategy. The method allows unattended, low-cost, and quantitative SSCP analysis using instruments that are widely accessible.

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

PCR single-stranded conformational polymorphism (SSCP) analysis is a simple and rapid electrophoretic technique for the sensitive detection of sequence variants of PCR products. Here we describe a cross-platform program package, quantitative interpretation of SSCP in capillary array (QUISCA), which allows semi-automated quantitative detection of sequence variants separated by multicolor fluorescence-based SSCP electrophoresis using various capillary array apparatus. The program, together with the QUISCAview as a graphical user interface, takes trace data in ASCII format and processes them with three modules: signal denoising/baseline subtraction, color-matrix construction/application, and calibration of peak positions between multiple capillary runs using internal standard peaks. QUISCA is compatible with data from various widely used capillary array sequencers and is suitable not only for finding or typing SNPs in individual DNAs but also for the accurate estimation of the allele frequencies of many SNPs using a pooled DNA strategy. QUISCA can also serve as a versatile core program for various fragment analyses.

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

PCR single-stranded conformational polymorphism (SSCP) analysis is a simple and rapid electrophoretic technique for the sensitive detection of sequence variants of PCR products. Here we describe a cross-platform program package, quantitative interpretation of SSCP in capillary array (QUISCA), which allows semi-automated quantitative detection of sequence variants separated by multicolor fluorescence-based SSCP electrophoresis using various capillary array apparatus. The program, together with the QUISCAview as a graphical user interface, takes trace data in ASCII format and processes them with three modules: signal denoising/baseline subtraction, color-matrix construction/application, and calibration of peak positions between multiple capillary runs using internal standard peaks. QUISCA is compatible with data from various widely used capillary array sequencers and is suitable not only for finding or typing SNPs in individual DNAs but also for the accurate estimation of the allele frequencies of many SNPs using a pooled DNA strategy. QUISCA can also serve as a versatile core program for various fragment analyses.

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

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

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

We present a high-throughput single-strand conformation polymorphism (SSCP) method, performed on a commercially available capillary array DNA sequencer. We tested various sieving matrices and electrophoretic conditions, using 51 DNA fragments which included 45 fragments carrying only one single nucleotide polymorphism (SNP), 4 fragments having two SNPs and 2 fragments with insertion or deletion. Resolution of alleles was improved by increasing concentrations of both sieving matrices and buffers, and all examined polymorphisms of DNA fragments were detected, most of them (45 fragments) as clearly split allele peaks in heterozygotes. Allele frequencies of SNPs can be estimated accurately by determining the relative amounts of alleles in pooled DNA. In this method, the turn-around time for the analysis of 96 samples is less than 3 h. These results demonstrate that capillary array-based SSCP is an efficient and accurate technique for the large-scale quantitative analysis of mutations/polymorphisms.

DOI： 10.1002/1522-2683(200207)23:14<2259::AID-ELPS2259>3.0.CO;2-8

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

We present a high-throughput single-strand conformation polymorphism (SSCP) method, performed on a commercially available capillary array DNA sequencer. We tested various sieving matrices and electrophoretic conditions, using 51 DNA fragments which included 45 fragments carrying only one single nucleotide polymorphism (SNP), 4 fragments having two SNPs and 2 fragments with insertion or deletion. Resolution of alleles was improved by increasing concentrations of both sieving matrices and buffers, and all examined polymorphisms of DNA fragments were detected, most of them (45 fragments) as clearly split allele peaks in heterozygotes. Allele frequencies of SNPs can be estimated accurately by determining the relative amounts of alleles in pooled DNA. In this method, the turn-around time for the analysis of 96 samples is less than 3 h. These results demonstrate that capillary array-based SSCP is an efficient and accurate technique for the large-scale quantitative analysis of mutations/polymorphisms.

DOI： 10.1002/1522-2683(200207)23:14<2259::AID-ELPS2259>3.0.CO;2-8

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

We show that single-nucleotide polymorphisms (SNPs) of moderate to high heterozygosity (minor allele frequencies >10%) can be efficiently detected, and their allele frequencies accurately estimated, by pooling the DNA samples and applying a capillary-based SSCP analysis. In this method, alleles are separated into peaks, and their frequencies can be reliably and accurately quantified from their peak heights (SD <1.8%). We found that as many as 40% of publicly available SNPs that were analyzed by this method have widely differing allele frequency distributions among groups of different ethnicity (parents of Centre d'Etude Polymorphisme Humaine families vs. Japanese individuals). These results demonstrate the effectiveness of the present pooling method in the reevaluation of candidate SNPs that have been collected by examination of limited numbers of individuals. The method should also serve as a robust quantitative technique for studies in which a precise estimate of SNP allele frequencies is essential - for example, in linkage disequilibrium analysis.

DOI： 10.1086/316928

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

OBJECTIVE. Our goal was to elucidate the CT and MR imaging characteristics in patents with autoimmune pancreatitis, which is a reversible chronic pancreatitis with an autoimmune cause. CONCLUSION. On CT and MR imaging, a capsulelike rim, which is thought to correspond to an inflammatory process involving peripancreatic tissues, appears to be a characteristic finding of autoimmune pancreatitis. Also, diffuse pancreatic enlargement along with hypointensity on T1-weighted MR images and delayed enhancement on dynamic CT and MR studies are other features of this disorder.

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

The effects of tumor necrosis factor (TNF)-α and -β on the spontaneous firing rate of ventromedial hypothalamic (VMH) neurons were examined in rat brain slice preparations. Of 89 neurons, 36 (40%) showed a decrease in the firing rate to 78.2 ± 4.0% (n = 36, mean ± SE) of the preapplication level after a bath application of 20 ng/ml (~1.2 nM) of TNF- α. This response to TNF-α still persisted in a low-Ca²⁺, high-Mg²⁺ medium. Six (7%) of the 89 neurons were excited and 47 (53%) were unaffected by TNF-α. The inhibitory responses induced by TNF-α were abolished in a solution that contained sodium salicylate (1.9 x 10^-8 M). In contrast, TNF-β at a dose of 20 ng/ml (~1.1 nM) increased the firing rate to +39.2 ± 6.5% (n = 11) of the preapplication level in 11 (24.5%) of 45 VMH neurons. Two of the 45 neurons (4.5%) were inhibited and 32 (71%) were unaffected by TNF-β. The threshold concentration of TNF-α to alter the VMH neuron activity was lower than that of TNF-β. Heat-inactivated TNFs were without effect. These findings suggest that TNF-α and -β act as neuromodulators in the VMH, at least partly through prostaglandin synthesis, and differentially modulate the VMH neuron activity.

Responsible for pages：5(2),2014. 98-101   Language：Japanese   Book type：Scholarly book

Responsible for pages：2014　vol.59　No.10　1292-1301   Language：Japanese   Book type：Scholarly book

Responsible for pages：Vol. 30, 10月増刊号　150-161   Language：Japanese   Book type：Scholarly book

Responsible for pages：Vol.25　No1   Language：Japanese   Book type：Scholarly book

褐色脂肪組織(Brown adipose tissue、BAT)または褐色脂肪はその名前のとおり通常の白色の脂肪組織と比較して褐色の色調を呈する脂肪組織である。多量のミトコンドリアを含んでいるため白色脂肪組織に比べはるかに多量の酸素を必要とする。活性化した褐色脂肪組織ではエネルギー代謝の亢進が認められ、核医学検査の一種であるPET検査によって糖代謝の亢進を画像によって評価可能である。ここでは画像診断の分野において近年認知度が高くなった褐色脂肪組織についてその特徴を概説する。

Responsible for pages：P128-131   Language：Japanese   Book type：Scholarly book

Responsible for pages：JCR News 　2020　No.235　19-21   Language：Japanese  

Responsible for pages：Vol.18 (No.8) 2020 46-49   Language：Japanese   Book type：Scholarly book

Responsible for pages：374-382   Language：Japanese   Book type：Scholarly book

Responsible for pages：342-349   Language：Japanese   Book type：Scholarly book

Responsible for pages：２０１３年５月号　241-244   Language：Japanese   Book type：Scholarly book

Responsible for pages：2011　Autum　No.15   Language：Japanese   Book type：Scholarly book

Responsible for pages：６核医学治療　362-370   Language：Japanese   Book type：Scholarly book

Responsible for pages：４インビボ検査各論　I. 腫瘍・炎症　318-337   Language：Japanese   Book type：Scholarly book

Language：Japanese   Book type：Scholarly book

Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Country：Japan  

本講演では大学病院に要求される放射線安全管理について概説する。近年、医療分野における放射線管理に関連する２つの重要な法律が改正された。2019年には放射線障害防止法がセキュリティー強化の観点から放射線規制法となり特定放射性同位元素への規制要求がなされた。医療現場においては腔内治療装置への防護措置が必要となった。また2020年には医療法施行規則の一部が改正された。その背景として日本人の医療被曝が国際的に多いこと、医療被曝には規制値がないことから欧米の考えをとりいれて対策をとることが規定された。被曝は大きく職業被ばく、医療被曝、公衆被曝に分類されるがそれぞれに防護の原則が適用される。そのうち医療被曝には線量限度が設けられておらず正当化と最適化によって防護を達成する。今回の改正では従来医師の裁量にまかせられていた最適化に特に着目し、管理体制の構築、職員研修、患者への説明、DRL（診断参考レベル）などの客観指標を利用した線量管理と記録が義務つけられた。以下は九州大学病院にて法令改正に合わせて行った対応や放射線安全管理について紹介する。X線透視装置を使用した医療では手技の高度化に伴い放射線曝射時間の延長と患者、術者の被ばく線量の増加が懸念される。特にERCP(内視鏡的逆行性胆管膵管造影)では透視時間が長くなる傾向にあり対策が必要である。透視装置へのカーテン型の遮蔽体の設置や水晶体外部被ばく減少のための防護メガネの装着が有効である。CT検査では放射線技師の被ばくのおそれは大きくないが、多相CTやdynamic撮影など装置性能とプロトコールの高度化に伴い患者の被ばく線量が増える傾向にある。同時に被曝低減のための新たな再構成法も開発されているがDRLを参考にして施設ごとのプロトコールを見直す必要がある。リニアックを使用した放射線治療では放射線技師の外部被曝への対策は基本的に不要であるが、治療装置の性能の定期的評価が必要である。密封線源を用いる腔内照射では外部被曝への対策と防護措置が必要となる。非密封の放射性同位元素を使用する核医学では各種の防護装置を使用し医療従事者の被ばくを防止する必要がある。核医学領域においてのDRLは投与量によって規定される。当院ではPET用の短半減期核種を製造するサイクロトロンがあるため、ホットセルからの分注、運搬における被曝防止にも注意する必要がある。またPET用核種は放射線エネルギーが比較的高いため、投与から撮影までの患者同線などに工夫が重要になる。高用量のβ線あるいはα線核種を治療に使用する核医学治療は近年急速に重要性を増している。核医学治療を施行するためには投与法の工夫、専用病室での隔離、隔離中の対応、排水管理などさまざまな防護措置が必要となる。またさらに近年では画像からの特定臓器の吸収線量推定も副作用の予測に重要である。

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都府　京都国際会議場   Country：Japan  

Usefulness of MTV measurement of FDG-PET images of malignant lymphoma using machine learning model

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都府　京都国際会議場   Country：Japan  

Usefulness of MTV measurement of FDG-PET images of malignant lymphoma using machine learning model

Event date： 2022.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Vancouver, BC, Canada   Country：Canada  

Event date： 2022.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Vancouver, BC, Canada   Country：Canada  

Event date： 2021.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：愛知県名古屋市　名古屋国際会議場   Country：Japan  

Establishment of automated tumor segmentation of whole-body FDG-PET using 3D U-net

Event date： 2021.6

Language：English   Presentation type：Oral presentation (general)  

Venue：online   Country：United States  

Other Link： https://www.snmmi.org/MeetingsEvents/EventDetail.aspx?EventID=60908

Event date： 2020.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：兵庫県神戸市   Country：Japan  

Relationship between the visualization of the lesion and uptake time of 131NaI

Event date： 2020.6

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：online   Country：United States  

Objectives: Radioiodine therapy is used to treat distant metastases from thyroid cancer. A reverse relationship between iodine and FDG accumulation is found in thyroid cancer lesions, the so-called “flip-flop” phenomenon. The aim of this study was to assess the relationship between iodine and FDG uptake in bone metastasis lesions from thyroid cancer.Methods: The cases of 20 patients who underwent radioiodine therapy for bone metastasis were studied retrospectively (age, 27-74 yrs; median, 62 yrs; males : females, 6 : 14). Iodine uptake was evaluated visually and the lesions showing iodine uptake more than background were determined as positive. FDG uptake was assessed using SUVmax. We compared FDG uptake between the lesions with (n=19) and without (n=88) iodine uptake in bone metastasis.Results: The bone metastasis lesions without iodine showed significantly higher FDG uptake than those with iodine uptake (p < 0.0001). However, the degree of FDG uptake in bone metastasis lesions was also relatively high (Median of SUVmax: 4.64). Thirty-nine out of 88 iodine-positive bone metastasis lesions (44.3 %) showed more than 5 of SUVmax. On the other hand, only one iodine-positive lesion (1.1 %) showed more than 10 of SUVmax, while 9 out of 19 (47.4 %) iodine-negative lesions did.Conclusions: Bone metastasis lesion from thyroid cancer not showing iodine uptake showed higher FDG uptake compared to those with iodine uptake. On the other hand, more than 40 % of bone metastasis lesions with iodine uptake showed relatively high FDG uptake (SUVmax>5). Enormously high degree of FDG uptake (SUVmax>10) was rare in the lesions with iodine uptake, while it was common in those without iodine uptake.

Event date： 2020.5 - 2020.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：WEB開催   Country：Japan  

[Objective]Evaluate and compare Population-Based Input Function (PBIF) to Image Derived Input Function (IDIF) [Materials and Methods]Dynamic imaging of SiPM PET/CT was performed on 70 patients with various diseases. 20 patients used IDIF, and 50 patients used PBIF to perform Patlac analysis.Six minutes of single bed cardiac scan was performed soon after the administration of 18F-FDG, followed by 90 minutes continuous bed motion whole-body dynamic scan. Ki(μg of FDG/min/100ml) and distribution volume (DV) was calculated and compared. [Results]The individual difference of PBIF was very small with the CV of 0.06(AUC). When using another person's IDIF, the effect on Ki was less than DV and within 10%. The best reproducibility was observed in the scanning after 40 minutes post FDG injection.[Conclusion]Patlak analysis using PBIF was useful as good as IDIF, with no apparent inferiority.

Event date： 2019.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Anaheim Convention Center Headquarter Hotel: Hilton Anaheim Anaheim, California   Country：Japan  

Background
C-11Methionine positron emission tomography has reported to be useful to distinguish brain tumor recurrence from radiation necrosis. We undertook this study to directly compare visual and semiquantitative analysis for the evaluation of recurrence in brain tumors.
Method
Thirty-nine patients with a history of treated brain tumors (32 primary brain tumor and 7 metastatic tumor) referred for evaluation of recurrent disease were initially included in the study. There were 24 males and 15 females (mean age: 39.1. ± 15.4 years; range: 15 to 69 years). All patients are suspected recurrence, persistence, or necrotic post-therapeutic changes and underwent the MET PET/CT study. Visual image interpretation was performed independently by 2 PET physicians using the fused PET/CT images. Images were also analyzed semiquantitatively using ratio of SUVmax of tumor and normal contralateral white matter (T/Nw) and grey matter (T/Ng). Imaging results were compared with histopathology on tumor excision or biopsy in 12 patients and with clinical follow-up in 27 patients.
Results
The final diagnosis was tumor recurrence in 28 patients and no recurrence/stable disease in 11 patients. Visual analyses were positive in 25 (64.1%) and negative in 9 (35.9%). The sensitivity, specificity and accuracy were 82.1%, 81.8% and 82.1% respectively. For the semiquantitative analysis, positive cases were seen in 26 (66.7%) (TNw) and 25 (64.1%) (TNg). The sensitivity, specificity and accuracy were [89.3(TNw); 85.7(TNg)], [90.9(TNw); 90.9(TNg)] and [89.7(TNw); 87.2(TNg)] respectively. Highest AUC of 0.93 was seen in TNw using the cut-off value of 1.95. There was no statistically significant differences among three methods.
Conclusion
Although, it was a slight difference, diagnostic performance using semiquantitative analysis using T/Nw was the best among the three method used in this study. MET-PET/CT was a useful technique to differentiate post-therapeutic changes from tumor presence in treated patients with brain tumor in whom diagnosis was nonconclusive.

Event date： 2019.5 - 2019.6

Language：English   Presentation type：Symposium, workshop panel (public)  

Country：China  

BACKGROUND:
Magnetic resonance imaging (MRI) is the investigation of choice for diagnosing cerebral glioma, but its capacity to differentiate tumor tissue from non-specific tissue changes is limited. 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a molecular imaging technique, which provides information on the metabolic behavior of the tumor. However, FDG-PET often leads to several controversies in making clinical decisions due to their high uptake of normal surrounding tissues, and pose difficulty in delineating treatment-induced necrosis, edema, inflammation, and pseudoprogression. Thus, it is imperative to find new approach to demarcate normal and tumor tissues. PET using radiolabeled amino acids is a promising technique and it increases diagnostic accuracy for brain tumor.
PURPOSE: We have provided some cases and literature of 11C methionine-PET (MET-PET) and other amino acid PET for gliomas, along with prognostic and diagnostic significance.
METHODS:
Review based on the authors' own research results and a selective literature review
RESULTS:
The use of radiolabeled amino acids allows better delineation of tumor margins and improves targeting of biopsy and radiotherapy, and planning surgery. In addition, amino acid imaging appears useful in distinguishing tumor recurrence from non-specific post-therapeutic necrosis, in predicting prognosis in low grade gliomas, and in monitoring metabolic response during treatment.
CONCLUSION:
Amino acid PET including MET-PET can lead to a better understanding of the existing controversies and can enhance our knowledge for future treatment of GBM patients based on their tumor gene signatures to achieve better prognosis and treatment outcome.

Event date： 2018.11

Language：Japanese  

Country：Japan  

Event date： 2018.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：沖縄市   Country：Japan  

Effect of spatial resolution on the PET Radiomics parameters of malignant tumors

Event date： 2018.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：沖縄市   Country：Japan  

Event date： 2018.6

Language：English  

Country：Japan  

Background
C-11Methionine positron emission tomography has reported to be useful to distinguish brain tumor recurrence from radiation necrosis. We undertook this study to directly compare F-18 flurodeoxyglucose (FDG) PET and C-11 methionine (MET) PET for the evaluation of recurrence in brain tumors.
Method
Thirty-seven patients with a history of treated brain tumors (31 primary brain tumor and 6 metastatic tumor) referred for evaluation of recurrent disease were initially included in the study. There were 22 males and 15 females (mean age: 38.7 ± 14.4 years; range: 15 to 65 years). All patients underwent the MET and FDG study within 2 weeks. Visual image interpretation was performed independently by 2 PET physicians for each tracer using the fused PET/CT images. Images were analyzed semiquantitatively using tumor to normal contralateral cortex ratios (T/N). Imaging results were compared with histopathology on tumor excision or biopsy in 10 patients and with clinical follow-up in 27 patients.
Results
The final diagnosis was tumor recurrence in 27 patients and no recurrence/stable disease in 10 patients. On FDG, findings in 23/37 (62.2%) were suggestive of recurrent tumors. On MET, findings in 28/37 (75.7%) cases were suggestive of recurrent tumors. Spatially separated secondary lesions were clearly delineated in 4 cases, 3 were glioblastoma multiforme (GBM) and 1 were anaplastic astrocytoma. Two of the secondary lesions were missed on FDG PET. Using a cutoff for T/N ratio on FDG of >0.90 to differentiate recurrence from no recurrence, sensitivity of FDG was 74.1%, whereas specificity was 70.0%. Area under the curve was 0.86. Using a cutoff for T/N ratio of >2.1 to differentiate recurrence from no recurrence, sensitivity of MET was 92.6%, whereas specificity was 80.0%. Area under the curve was 0.95.
Conclusion
Semiquantitative analysis of MET can provide more informative values than FDG to aid in the differentiation of tumor recurrence from radiation necrosis.

Event date： 2018.6

Language：English  

Country：Japan  

Event date： 2018.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2018.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京都   Country：Japan  

Event date： 2018.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜市   Country：Japan  

[Objective] Ventricular assist device (VAD) is an artificial heat supporting right ventricle, left ventricle or both ventricles. Drive-line infection is one of the major complications of implantable VAD and FDG-PET is useful to detect the inflammatory focus. The aim of this study is to analyze the frequent site of drive-line infection and the FDG distribution in and around VAD components.
[Materials and Methods] Nine patients who received VAD implantation were included (M : F = 5 : 4, Median: 51.5 yrs). FDG-PET/CT was performed to investigate the inflammatory focus. FDG uptake (SUVmax) in the following parts was measured and compared: the blood sending tube, the region around pump, blood removing tube and a drive-line (with and without infection).
[Results] FDG uptake around a pump was low (SUVmax=1.2-3.4, Median 2.35). FDG uptake around pump was significantly lower than that of the blood sending tube (SUVmax=2-5.2, Median: 3.5) and blood removing tube (SUVmax=1.2-7.1, median=3.75). High FDG uptake (SUVmax>5) in blood removing tube was observed in 3 out of 9 patients (33.3%). Drive-line infection always involved the portion close to skin and showed high FDG uptake (SUVmax=5.7-17.3, Median: 9.05). FDG uptake in the drive-line without infection was low (SUVmax=0.9-2.7, Median: 1.55)
[Conclusion] FDG uptake in the blood sending and blood removing tubes was significantly higher compared to the region around pump. Blood removing tube occasionally showed high FDG uptake. Drive-line infection occurred from the site close to skin.

Event date： 2018.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：長崎大学病院   Country：Japan  

Event date： 2017.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神奈川県　パシフィコ横浜   Country：Japan  

Event date： 2017.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神奈川県　パシフィコ横浜   Country：Japan  

Event date： 2017.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神奈川県　パシフィコ横浜   Country：Japan  

Event date： 2017.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：久留米シティプラザ   Country：Japan  

Event date： 2017.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：沖縄県那覇市   Country：Japan  

Event date： 2016.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋国際会議場   Country：Japan  

Event date： 2016.11

Language：English   Presentation type：Oral presentation (general)  

Venue：名古屋国際会議場   Country：Japan  

Event date： 2016.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋国際会議場   Country：Japan  

Event date： 2016.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宮崎県宮崎市   Country：Japan  

Event date： 2016.6

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：San Diego, USA   Country：United States  

Event date： 2016.6

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：San Diego, USA   Country：United States  

Event date： 2016.6

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：San Diego, USA   Country：United States  

Event date： 2016.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜市   Country：Japan  

Event date： 2016.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜市   Country：Japan  

Event date： 2016.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡県福岡市   Country：Japan  

Event date： 2015.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京都   Country：Japan  

Event date： 2015.10

Language：English   Presentation type：Oral presentation (general)  

Venue：東京都   Country：Japan  

Event date： 2015.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京都   Country：Japan  

Event date： 2015.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州市   Country：Japan  

Event date： 2015.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2015.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大分県別府市   Country：Japan  

Event date： 2015.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2015.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市   Country：Japan  

Event date： 2015.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Baltimore, USA   Country：United States  

Event date： 2015.6

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Baltimore, USA   Country：United States  

Event date： 2015.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Baltimore, USA   Country：United States  

Event date： 2015.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Baltimore, USA   Country：United States  

Event date： 2015.5

Language：English   Presentation type：Oral presentation (general)  

Venue：Vienna Austria   Country：Austria  

Event date： 2014.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：飯塚市   Country：Japan  

Event date： 2014.6

Language：English  

Venue：St. Louis   Country：United States  

Event date： 2014.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福山市   Country：Japan  

Event date： 2012.6

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Maiami Florida   Country：United States  

Purpose: To evaluate the usefulness of recovery-collected SUVs in the clinical diagnosis of malignant lymphoma patients.
Materials and Methods: Previously reported recovery-collection using simple table look-up method was used in this study. Recovery coefficient was estimated using size and signal-background ratio by phantom experiment. Fifty three patients of malignant lymphoma (DLBCL; 37, FL; 16) were subjected to FDG-PET/CT for initial staging. Recovery-collected SUVs (SUVcor) were calculated and average±SD, coefficient of variation (CV) of SUVcor were compared with those of conventional SUV within the patient and between the groups divided by histology and prognosis.
Result: Average±SD of SUVmax, SUVcor were higher in DLBCL (14.5±9.1, 18.6±9.6) than in FL(8.5±2.6, 11.7±3.24)( p<0.05). With recovery collection, average±SD was increased and CVs within the patient were significantly decreased in both type of histology(p<0.05). CVs of SUVcor was significantly smaller in good responder (20cases) than those of poor responder (17) (p<0.05).
Conclusion: Uptakes of FDG free from partial-volume effect can be measured correctly with this method. Variability of pretreatment SUVs with size-collection is one of the independent predictor of the prognosis of patient with DLBCL.

Event date： 2011.10

Venue：筑波   Country：Japan  

目的：90Yは純β線放出核種であるためガンマカメラでの集積の評価は困難である。我々は90Yの壊変にともなって発生する電子対生成に着目し、微量のポジトロンをPETカメラで検出可能か否かを検討した。
対象と方法： リンパ腫病変へのイブリツモマブチウキセタン(ゼヴァリン)集積の程度を推定するため8人のリンパ腫患者の111In SPECT/CTデータを解析し、集積程度を推定した。90Yの検出能および直線性を二種類のPETシステム(BGOおよびLSO)を用いて測定しTime of Flight(TOF)の有無を含め、各種パラメータによる違いを検討した。また3名の患者について90Yゼヴァリン投与後48時間後に40分間のPET/CT撮像を行った。
結果：111In SPECT/CTから推定された90Yの病巣への集積は127.2±77MBq/ml(40~250)であった。ファントム実験の信号の直線性および視覚評価での画質はTOFを併用したLSOシステムで最もよく、70 から2500 (KBq/ml) の間で直線性が保たれていた。740kBq/ml 以上の信号はいずれのシステムにおいても検出可能であったが200KBq以下の信号はBGOシステムでは検出困難であった。LSO-TOFシステムを用いた3名の臨床データではいずれもFDG-PET、In-SPECTにて集積が描出された部位と一致して集積が描出可能であった。
結論： PETを用いて90Yの信号を検出ことが可能であり、LSO-TOFシステムが最も優れていた。 低いシグナルではあるが本研究の結果は90YをもちいたRI内用療法の集積評価にPET/CTが利用可能であることを示す。

Event date： 2011.6

Venue：San Antonio, Texas   Country：United States  

Event date： 2011.6

Venue：San Antonio, Texas   Country：United States  

Event date： 2011.5

Presentation type：Oral presentation (general)  

Venue：web 開催   Country：Japan  

背景】FDG-PET/CT検査にて悪性肝腫瘍が偽陰性となる主要な原因として限られた空間分解能のほか肝自体の集積による低いS/N比が挙げられ、S/N比の向上が今後の重要な課題である。
【目的】全身PET撮像終了後、肝の追加dynamic収集を行い長時間画像および集積時間変化の画像を作成し、肝腫瘍の診断における臨床的有用性を評価する。
【方法】種々の肝悪性腫瘍に対しFDG-PET/CTを施行した症例(39例 53 病変：転移性肝癌20例、肝細胞癌12例、胆管細胞癌7例)について全身撮像終了後20分間のリストモード収集を追加し、20分間の追加加算画像とともにFDG集積の時間変化率の画像を作成した。Signal noise ratio (SNR)、Tumor to liver ratio (TLR)、病変検出能について通常のPET撮像と比較した。
【結果】20分間の追加画像では通常撮像に比べSNRが平均49%向上(P<0.001)し、TLRも有意に上昇した(p<0.01)。また8/39（20.5%）の症例で通常撮像では検出困難な病変を指摘できた。集積時間変化率の画像も通常撮像に比べ高い検出率をしめし、サイズの大きな病変ほど変化率が高い傾向にあった。追加撮像の有用性は大腸癌、膵癌の転移で高く、肝と同程度の集積を呈した一部のHCCでは追加画像、集積変化率の画像ともに有用性は低かった。
【結論】本手法は大幅な検査時間枠の延長なく臨床に応用できる方法であり、簡便にS/N比を向上させ、診断能を向上した。肝細胞癌以外の肝病変に対しては有用な方法である。

Event date： 2010.11

Presentation type：Oral presentation (general)  

Venue：埼玉県大宮   Country：Japan  

ariability of size-collected SUV evaluated by FDG-PET/CT predicts prognosis of patients with diffuse large cell lymphoma.

Event date： 2010.6

Presentation type：Symposium, workshop panel (public)  

Venue：Salt Lake City   Country：United States  

Other Link： http://www.snm.org/index.cfm?PageID=9219

Event date： 2010.2

Presentation type：Oral presentation (general)  

Venue：コンパルホール（大分市府内町1-5-38）   Country：Japan  

Event date： 2009.10

Presentation type：Oral presentation (general)  

Venue：旭川、　北海道   Country：Japan  

Event date： 2009.6

Presentation type：Oral presentation (general)  

Venue：Toronto   Country：Canada  

Event date： 2009.2

Presentation type：Oral presentation (general)  

Venue：佐賀大学医学部   Country：Japan  

Event date： 2008.10

Presentation type：Oral presentation (general)  

Venue：千葉　幕張メッセ   Country：Japan  

Event date： 2008.6

Presentation type：Oral presentation (general)  

Venue：New Orleans.   Country：United States  

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

PET(PET-CT)は現在悪性リンパ腫の診療においては不可欠の検査法となっている。PETはリンパ腫病変の原発巣、節外病変の検出において感度、特異度ともに従来の造影CTやガリウムシンチグラフィーを上回っており、より正確な病気診断が可能となったためである。リンパ腫は比較的細胞密度が高く、PETにて高率に高集積を呈しやすい点や空間的に離れた部位に短期間で病変を形成する特徴があることから、一度の検査で全身が評価できるPETの特性が有利となる。特にホジキンリンパ腫(HL)やびまん性B細胞性リンパ腫(DLBCL)のような中・高悪性の非ホジキンリンパ腫ではFDGの高度な取り込みが認められることから従来の検査法では見逃されていた病変を指摘できる点に加え、その集積の変化を治療効果の判定指標に使用することができる。また従来のCTでは不可能であった残存軟部腫瘤の活動性を評価できるため、追加治療の要否の判定に有用である。このようなPETの有用性が認められ訂版IWC(国際ワークショップ基準)にはFDG-PET検査が組み込まれた。近年では化学療法早期のPET所見およびその所見の変化が治療の奏功や予後の予測に有用であることが示唆されつつある(interim PET)。これまで臨床で用いられてきた予後予測因子は、治療開始前の臨床情報（病期、LDH、年齢、患者のperformance statusなど）に基づくものであるのに対し、治療途中のFDG-PET画像は患者ごとの特定の治療に対する反応性を反映しているため、治療結果を早めに確認して治療法を再検討できる利点が期待できる。しかしながらこのinterim PET を広く臨床に普及させるためにはまだ解決すべき問題点が残されている。特に問題となるのが偽陽性ならびに陽性所見の定義である。現在用いられている代表的な判定基準として、縦隔や肝臓といった内部リファレンスを用いた５ポイントスケール（Deauville 5 point-scale）が挙げられるが、小児への応用など課題も残される。本講演では悪性リンパ腫診療におけるPET検査の診断、治療効果判定の現状と現在進行中のPETの予後予測因子としての有用性と層別化治療を検証する臨床試験を紹介する。

Presentation type：Oral presentation (general)  

Venue：San Diego, USA   Country：United States  

Presentation type：Oral presentation (general)  

Venue：San Diego, USA   Country：United States  

Presentation type：Oral presentation (general)  

Venue：San Diego, USA   Country：United States  

Presentation type：Oral presentation (general)  

Venue：San Diego, USA   Country：United States  

Presentation type：Oral presentation (general)  

Venue：San Diego, USA   Country：United States  

Presentation type：Oral presentation (general)  

Venue：Chicago. USA   Country：United States  

Presentation type：Oral presentation (general)  

Venue：Chicago. USA   Country：United States  

Presentation type：Oral presentation (general)  

Country：United States  

The 18F-FAZA /FDG uptake ratio: Potential Index of tumor hypoxia?

Presentation type：Oral presentation (general)  

Venue：Washington, D.C., USA   Country：United States  

Presentation type：Oral presentation (general)  

Venue：Washington, D.C., USA   Country：United States  

Presentation type：Oral presentation (general)  

Venue：Hawaii, USA   Country：United States  

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2024.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学医学部　医学図書館   Country：Japan  

Event date： 2023.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：J:COMホルトホール大分   Country：Japan  

Event date： 2023.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：沖縄県　那覇市   Country：Japan  

Event date： 2023.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡県　久留米市   Country：Japan  

【背景】
神経内分泌腫瘍に対するペプチド受容体核医学内用療法（peptide receptor radionuclide therapy：PRRT）としてLu-177 oxodotreotideが本邦でも施行されている。その薬剤分布について、国内においては保険適用上ソマトスタチン受容体シンチグラフィ（In-111 pentetreotide、以下SRS）が利用されるが、SRSの集積程度とルタテラの集積程度との関係については不明である。本研究の目的は、半導体SPECTを用いてSRSおよびルタテラの集積程度を定量化し、SRSの集積程度がルタテラの治療予測における有用性を検証する。
【方法】
対象は2021年12月～2022年12月に当院で初回のPRRTを施行した7例（男性6名、女性1名、年齢 48-76）。全例で投与2ヶ月以内にSRSおよびFDG-PET/CTを施行した。SRSはRI投与後4時間後（SRS4）および24時間後（SRS24）の撮像、PRRTはRI投与後24時間後の撮像を行った。治療前のCT、FDG-PET/CTで指摘できた23病変についてSRS、PRRT、FDG-PETそれぞれのSUV（Standard Uptake Vlaue）を計測し、各2者間での相関を検討した。
【結果】
SRS4とPRRTについては有意な正の相関を認めた（R2＝0.206、p=0.03）。SRS4とFDG（R2＝0.004、p=0.76）、PRRTとFDG（R2＝0.007、p=0.69）についてはいずれも有意な相関を認めなかった。またSRS24とPRRT（R2＝0.130、p=0.09）あるいはFDG（R2＝0.002、p=0.84）でも有意な相関を認めなかった。
【結論】
SRS4時間後像のSUVは神経内分泌腫瘍に対するPRRTの集積程度の予測に有用である。

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡市　福岡大学　ハイブリッド開催   Country：Japan  

Event date： 2022.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宮崎県宮崎市（オンライン開催）   Country：Japan  

Event date： 2021.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：愛知県名古屋市　名古屋国際会議場   Country：Japan  

Establishment of automated tumor segmentation of whole-body FDG-PET using 3D U-net

Event date： 2021.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：愛知県名古屋市　名古屋国際会議場   Country：Japan  

Comparison of CE-CT and scintigraphy in salivary gland dysfunction after repeated I-131 therapy

Event date： 2021.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡県福岡市　web開催   Country：Japan  

【背景】FDGのDINAMIC収集を用いてKiやDV（distribution volume）等のパラメトリック画像作成が可能である。しかし動脈入力関数の取得にはFDG注射時の撮像が必要であり、必ずしも全例に適応できない。そこで本研究では標準入力関数の利用を考慮しFDG入力関数の個人間のばらつきや再現性について検討を行った。
【方法】5名の患者についてFDG投与時に胸部dynamic撮像を行い大動脈に関心領域をおいて入力関数を測定した。データは1秒単位でresampleを行い、関心領域内の平均Bq/Mlを算出しTime to peak,変曲点の時間、AUC、second peakについて比較を行った。
【結果】time to peak は（22.90±2.24s;CV=0.098）、変曲点までの時間は（57.50±2.10s;CV=0.036）、AUCは（57±2.10MBq*sec CV=0.057）,2つのpeakの比は（3.79±1.40 CV=0.37）、peak間の時間は（26.00±3.74s;CV=0.14）であった。
【結論】限られたサンプル数であるが、peak比、peak間時間を除き入力関数の再現性は高く今度標準化された入力関数を用いてのパラメトリックPET施行の可能性が期待される。

Event date： 2021.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大分県大分市（オンライン開催）   Country：Japan  

Event date： 2020.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：佐賀県佐賀市   Country：Japan  

Event date： 2020.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：佐賀県佐賀市   Country：Japan  

Event date： 2020.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：佐賀県佐賀市   Country：Japan  

Event date： 2020.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡県北九州市   Country：Japan  

Event date： 2020.1

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2019.11

Language：Japanese   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：愛媛県松山市   Country：Japan  

Event date： 2019.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：愛媛県松山市   Country：Japan  

Event date： 2019.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：愛媛県松山市   Country：Japan  

【目的】メチオニンPET/CTを⽤いて脳腫瘍の再発と放射線壊死の鑑別を⾏う
【⽅法】再発が疑われた脳腫瘍治療歴のある患者39例（原発性脳腫瘍︓32、転移性腫瘍︓7、男性24︓⼥性15）に対しメチオニンPET/CTを施⾏し、視覚的評価と定量指標を⽤いた評価を⾏った。定量評価指標としてSUVmax値、正常対側⽩質⽐(T/Nw)、正常対側灰⽩質⽐（T/Nｇ）を⽤いた。
【結果】最終診断は28⼈の患者で腫瘍再発であった。視覚評価では25⼈で陽性であり、9⼈で陰性であった。感度、特異度および正確度はそれぞれ82.1％、81.8％および82.1％であった。半定量分析では、26⼈（66.7％）（TNw）および25⼈（64.1％）（TNg）に陽性例が⾒られた。感度、特異度および正確度は[89.3（TNw）; 85.7（ＴＮｇ）］、［90.9（ＴＮｗ）︔ 90.9（ＴＮｇ）］および[89.7(TNw); 87.2(TNg)]であった。ＴＮｗ=１．９５のカットオフ値で最も⾼いＡＵＣ(０．９３)が⾒られた。
【結論】本研究で使⽤した3つの⽅法の中では、わずかな違いではあるが、T/ Nwを使⽤した半定量指標を⽤いた診断能が最もよかった。

Event date： 2019.8

Language：Japanese   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：福島県福島市   Country：Japan  

シーメンス社のBiograph Visionが4月から当院に導入されたので、初期使用経験を報告する。本装置はSiPMを装備した半導体PET装置であり、クリスタルサイズが3.2×3.2㎜で1.6㎜での切り出しが可能である。またTOF時間分解能が214psecと高いTOF時間分解能を持つ。NEMAファントムの検討では3min、iteration/subset= 3/5、TOF+PSFの条件下でNECphantom=20、N10=5.4、QH10㎜/N10㎜=39.8、RC10㎜=0.86であった。また本装置flow-motionを応用し、全身dynamic撮像が可能である。大動脈の動脈入力関数から全身のKi画像やDV（distribution volume）画像などのパラメトリック画像の算出が可能である。一部症例について入力関数のばらつきや結果の再現性について評価を行ったので報告する。

Event date： 2019.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡県北九州市   Country：Japan  

【背景】FDGのDINAMIC収集を用いてKiやDV（distribution volume）等のパラメトリック画像作成が可能である。しかし動脈入力関数の取得にはFDG注射時の撮像が必要であり、必ずしも全例に適応できない。そこで本研究では標準入力関数の利用を考慮しFDG入力関数の個人間のばらつきや再現性について検討を行った。
【方法】5名の患者についてFDG投与時に胸部dynamic撮像を行い大動脈に関心領域をおいて入力関数を測定した。データは1秒単位でresampleを行い、関心領域内の平均Bq/Mlを算出しTime to peak,変曲点の時間、AUC、second peakについて比較を行った。
【結果】time to peak は（22.90±2.24s;CV=0.098）、変曲点までの時間は（57.50±2.10s;CV=0.036）、AUCは（57±2.10MBq*sec CV=0.057）,2つのpeakの比は（3.79±1.40 CV=0.37）、peak間の時間は（26.00±3.74s;CV=0.14）であった。
【結論】限られたサンプル数であるが、peak比、peak間時間を除き入力関数の再現性は高く今度標準化された入力関数を用いてのパラメトリックPET施行の可能性が期待される。

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡県福岡市   Country：Japan  

Event date： 2019.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：鹿児島市   Country：Japan  

Event date： 2018.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本市   Country：Japan  

Event date： 2018.11

Language：Japanese  

Country：Japan  

Event date： 2018.11

Language：Japanese  

Country：Japan  

Event date： 2018.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：沖縄市   Country：Japan  

Quantitative parameters and metabolic heterogeneity of FDG-PET in oropharyngeal cancer.

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本市   Country：Japan  

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本市   Country：Japan  

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本市   Country：Japan  

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜市   Country：Japan  

Assessment of the effect of urinary excretion rate of 18F-Sodium fluoride on the SUV of NaF PET/CT

Event date： 2018.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：長崎市   Country：Japan  

Event date： 2016.3

Language：Japanese  

Venue：福岡市九大百年講堂   Country：Japan  

Event date： 2015.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪国際会議場   Country：Japan  

Event date： 2014.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：松山市   Country：Japan  

Event date： 2014.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：佐賀市   Country：Japan  

Event date： 2014.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：佐賀市   Country：Japan  

Event date： 2014.6

Language：English  

Venue：St. Louis   Country：United States  

Event date： 2014.6

Language：English  

Venue：St. Louis   Country：United States  

Event date： 2014.6

Language：English  

Venue：St. Louis   Country：United States  

Event date： 2014.6

Language：English  

Venue：St. Louis   Country：United States  

Event date： 2014.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜市   Country：Japan  

Event date： 2014.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州市   Country：Japan  

Event date： 2014.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州市   Country：Japan  

Event date： 2011.11

Presentation type：Symposium, workshop panel (public)  

Venue：埼玉県大宮市   Country：Japan  

Impact of PET/CT on clinical oncology; for the evaluation of treatment response and prospection :
malignant lymphoma

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：5

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：4