Shuhei Sato

Okayama University, Okayama, Okayama, Japan

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Publications (44)89.96 Total impact

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    ABSTRACT: Epicardial adipose tissue (EAT) volume is reported to be associated with coronary plaques. We evaluated whether non-invasive measurement of EAT thickness by echocardiography can predict high-risk coronary plaque characteristics determined independently by coronary computed tomography (CT) angiography. We enrolled 406 patients (mean age 63 years, 57 % male) referred for 64-slice CT. EAT was measured on the right ventricle free wall from a parasternal long-axis view at the end of systole. High-risk coronary plaques were defined as low-density plaques (<30 Hounsfield units) with positive remodeling (remodeling index >1.05). Patients were divided into thin or thick EAT groups using a cutoff value derived from receiver operator characteristic curve analysis for discriminating high-risk plaques. The receiver operator characteristic cutoff value was 5.8 mm with a sensitivity of 83 % and specificity of 64 % (area under the curve 0.77, 95 % confidence interval 0.70–0.83, p < 0.01). Compared with the thin EAT group, the thick EAT group had a high prevalence of low-density plaques (4 vs. 24 %, p < 0.01), positive remodeling (39 vs. 60 %, p < 0.01), and high-risk plaques (3 vs. 17 %, p < 0.01). Multiple logistic analysis revealed that thick EAT was a significant predictor of high-risk plaques (odds ratio 7.98, 95 % confidence interval 2.77–22.98, p < 0.01) after adjustment for covariates, including conventional risk factors, visceral adipose tissue area, and medications. The measurement of EAT thickness by echocardiography may provide a non-invasive option for predicting high-risk coronary plaques.
    No preview · Article · Feb 2016 · Heart and Vessels
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    ABSTRACT: The objective of this study was to assess factors affecting image quality of 320-row computed tomography angiography (CTA) of coronary arteries in children with congenital heart disease (CHD). We retrospectively reviewed 28 children up to 3 years of age with CHD who underwent prospective electrocardiography (ECG)-gated 320-row CTA with iterative reconstruction. We assessed image quality of proximal coronary artery segments using a five-point scale. Age, body weight, average heart rate, and heart rate variability were recorded and compared between two groups: patients with good diagnostic image quality in all four coronary artery segments and patients with at least one coronary artery segment with nondiagnostic image quality. Altogether, 96 of 112 segments (85.7 %) had diagnostic-quality images. Patients with nondiagnostic segments were significantly younger (10.0 ± 11.6 months) and had lower body weight (5.9 ± 2.9 kg) (each p < 0.05) than patients with diagnostic image quality of all four segments (20.6 ± 13.8 months and 8.4 ± 2.5 kg, respectively; each p < 0.05). Differences in heart rate and heart rate variability between the two imaging groups were not significant. Receiver operating characteristic analyses for predicting patients with nondiagnostic image quality revealed an optimal body weight cutoff of ≤5.6 kg and an optimal age cutoff of ≤12.5 months. Prospective ECG-gated 320-row CTA with iterative reconstruction provided feasible image quality of coronary arteries in children with CHD. Younger age and lower body weight were factors that led to poorer image quality of coronary arteries.
    No preview · Article · Nov 2015 · Pediatric Cardiology
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    ABSTRACT: To evaluate the relevance of high-resolution computed tomography (HRCT) findings and fluorine-18-fluorodeoxyglucose ((18)F-FDG) uptake for risk stratification of visceral pleural invasion by lung adenocarcinoma. The HRCT findings and (18)F-FDG uptake for lung adenocarcinomas with pleural contact on CT were retrospectively analyzed in 208 consecutive patients (94 females and 114 males; median age, 69.0 years) between January 2009 and December 2013, with institutional review board approval. The HRCT findings and maximum standardized uptake value (SUVmax) were recorded for each patient. Multivariate logistic regression was used for statistical analysis, and subgroup analysis stratified for whole tumor size ≤3 cm was also performed. Multivariate analysis showed that SUVmax [odds ratio (OR) 1.09, 95 % confidence interval (CI) 1.02-1.16, P = 0.014] and obtuse angle (OR 4.14, 95 % CI 1.97-8.74, P < 0.001) were significant independent predictors for visceral pleural invasion. Receiver operating characteristic (ROC) analysis showed that, compared with the multivariate models [area under the curve (Az) 0.819-0.829], SUVmax alone (Az 0.815) was useful in predicting visceral pleural invasion. In the subgroup analysis, multivariate analysis showed that SUVmax (OR 1.29, 95 % CI 1.12-1.50, P = 0.001) and contact length with the pleura (OR 1.13, 95 % CI 1.05-1.22, P = 0.001) were significant independent predictors for visceral pleural invasion. ROC analysis showed that SUVmax alone (Az 0.844) showed similar diagnostic performance to the multivariate models (Az 0.845-0.857). SUVmax alone and multivariate models including SUVmax are useful for the prediction of visceral pleural invasion by lung adenocarcinoma.
    No preview · Article · Jul 2015 · Annals of Nuclear Medicine
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    ABSTRACT: Nonalcoholic fatty liver disease is associated with a risk of coronary artery disease (e.g., diabetes mellitus, dyslipidemia, metabolic syndrome). We evaluated whether nonalcoholic hepatic steatosis is associated with high-risk plaques as assessed by multidetector computed tomography (CT). This retrospective study involved 414 participants suspected of having coronary artery disease. Nonalcoholic hepatic steatosis was defined as a liver-to-spleen fat ratio of <1.0 and the presence and appropriate characteristics of coronary-artery plaques as assessed by coronary CT angiography. High-risk plaques were identified, as were low-density plaques, positive remodeling, and spotty calcification. Compared with patients who did not have nonalcoholic hepatic steatosis, patients with nonalcoholic hepatic steatosis had more low-density plaques (21% vs. 44%, p<0.01), positive remodeling (41% vs. 58%, p = 0.01), and spotty calcification (12% vs. 36%, p<0.01). The number of high-risk plaques in patients with nonalcoholic hepatic steatosis was greater than in those without nonalcoholic hepatic steatosis (p<0.01). Patients with nonalcoholic hepatic steatosis were more likely to have high-risk plaques than were those with only an elevated level of visceral adipose tissue (≥86 cm2; 35% vs. 16%, p<0.01). Multivariate analyses that included nonalcoholic hepatic steatosis, amount of visceral adipose tissue, and the presence/absence of traditional risk factors demonstrated that nonalcoholic hepatic steatosis was an independent predictor of high-risk plaques (odds ratio: 4.60; 95% confidence interval: 1.94-9.07, p<0.01). Diagnosis of nonalcoholic hepatic steatosis may be of value when assessing the risk of coronary artery disease.
    Full-text · Article · Jun 2015 · PLoS ONE
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    ABSTRACT: This retrospective study aims to evaluate the diagnostic capacity of thallium-201 (201Tl) scintigraphy for differentiating malignant bone tumors from benign bone lesions. Between January 2006 and December 2012, 279 patients with bone lesions (51 malignant and 228 benign) underwent 201Tl scintigraphy before treatment. To evaluate 201Tl uptake, we investigated tumor-to-background contrast (TBC) as well as TBC washout rate (WR). The differences of TBC on early and delayed images and WR were estimated by the Mann-Whitney U test. Receiver operating characteristic (ROC) analyses were used to determine the cut-off TBC values for differentiating malignant bone tumors from benign bone lesions. There were statistically significant differences in median TBC between malignant tumors and benign lesions. These differences occurred for early imaging (1.57 vs. 0.09, p < 0.001) as well as for delayed imaging (0.83 vs. 0.07, p < 0.001). However, there was no statistical difference in WR between malignant tumors and benign lesions (44 vs. 43 %, NS). The chosen TBC cut-off value was 0.68 for early imaging and 0.38 for delayed imaging. Using these cut-off values, the prediction of malignancy had a 77 % sensitivity, 74 % specificity, and 75 % accuracy for early imaging and an 80 % sensitivity, 76 % specificity, and 77 % accuracy for delayed imaging. 201Tl scintigraphy may have the ability to distinguish malignant bone tumors from benign bone lesions.
    No preview · Article · Jun 2015 · Annals of Nuclear Medicine
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    ABSTRACT: Cardiac CT is an excellent tool for evaluating the anatomy of a secundum atrial septal defect (ASD). However, a comprehensive assessment of its usefulness, including measurement of the pulmonary to systemic blood flow ratio in secundum ASD patients, has not been performed. Therefore, this study was designed to evaluate the usefulness of CT for assessing the hemodynamics of secundum ASD in adults compared with transesophageal echocardiography (TEE), transthoracic echocardiography, and invasive catheterization. Fifty adult patients with secundum ASD were enrolled. Cardiac CT scans (128-slice multidetector CT instrument) were acquired. These were followed by 2-dimensional reconstruction of the secundum ASDs to determine the defect size, the rim length between the outer edge of the defect, and the pulmonary to systemic blood flow (Qp/Qs) ratio. The maximum sizes of the secundum ASDs derived from CT and TEE studies were comparable (21.2 ± 8.0 vs 20.0 ± 7.3 mm; P = .41; r = 0.960; P < .001). The rim lengths for the aortic, mitral, and tricuspid valves; the inferior vena cava; and posterior atrium were also comparable between CT and TEE measurements. The mean Qp/Qs ratio that was derived from CT measurements was comparable with that found by invasive catheterization (2.3 ± 0.7 vs 2.3 ± 0.8; P = .73; r = 0.786; P < .001). Cardiac CT is feasible for assessing pathology and the severity of secundum ASD in adults. Copyright © 2015 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.
    No preview · Article · May 2015 · Journal of Cardiovascular Computed Tomography
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    ABSTRACT: The aims of this prospective study were to assess the relationship between tumor aggressiveness and Tc-99m (V) dimercaptosuccinic acid (DMSA) uptake in chondrogenic bone tumors and the value of Tc-99m (V) DMSA scintigraphy for differentiating benign from malignant tumors. Twenty-four patients with chondrogenic tumors (19 benign and five malignant) underwent Tc-99m DMSA (V) scintigraphy. Radiopharmaceutical uptake was classified using a three-point scale to allow a visual-only analysis, and a tumor-to-background contrast (TBC) was computed using regions of interest to provide a semiquantitative analysis. Spearman's correlation coefficient was used to assess the correlation between tumor aggressiveness and TBC. The difference in TBC between benign and malignant tumors was analyzed with the Mann-Whitney U-test. An appropriate cutoff value of TBC was chosen for the diagnosis of malignancy of a tumor using receiver operating characteristic analysis. Six benign tumors showed negative uptake (uptake score 0), whereas 13 benign tumors showed positive uptake (n=10 uptake score 1; n=3 uptake score 2). All chondrosarcomas showed positive uptake (n=2 uptake score 1; n=3 uptake score 2). A significant correlation was found between tumor aggressiveness and TBC. A significant difference was seen in TBC between benign and malignant tumors. With the chosen cutoff value of TBC equal to 0.611, the sensitivity was 80.0%, specificity was 78.9%, the positive predictive value was 50.0%, and the negative predictive value was 93.8%. Tc-99m (V) DMSA scintigraphy may have the potential to improve diagnostic methods for detecting chondrosarcomas using visual and/or semiquantitative analyses.
    No preview · Article · Apr 2015 · Nuclear Medicine Communications
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    ABSTRACT: Coronary artery calcification (CAC) is associated with the incidence of congestive heart failure. We evaluated the association between CAC and left ventricular diastolic dysfunction (LVDD) in elderly patients without coronary artery disease. Coronary computed tomography was performed in 1,021 consecutive patients >55 years of age who were suspected of having coronary artery disease. A total of 530 patients (age, 70 ± 8 years; 56 % men) with a LV ejection fraction >50 % and without obstructive coronary artery disease and a history of coronary artery disease were included in the analysis. LVDD was defined according to a standard algorithm by echocardiography (septal e' <8, lateral e' <10, and left atrial volume index ≥34 mL/m(2)). A total of 224 of 530 patients had LVDD. CAC scores in patients with LVDD were higher than those in patients without LVDD (p < 0.01). The prevalence of LVDD in patients with CAC scores ≥400 was greater than that in patients with CAC scores of 0-9 (58 vs. 34 %, p < 0.01). After adjustment for confounding factors, the CAC score was associated with LVDD, with an odds ratio of 1.96 (95 % confidence interval: 1.11-3.43, p = 0.02) for a CAC score ≥400 compared with a CAC score of 0-9. A CAC score ≥400 was associated with LVDD in elderly patients without CAD in this population. Further prospective studies are needed to evaluate the clinical relevance of CAC as a risk of heart failure with preserved ejection fraction.
    No preview · Article · Feb 2015 · Heart and Vessels
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    ABSTRACT: Multi-detector coronary CT angiography (CCTA) can detect coronary stenosis, but it has a limited ability to evaluate myocardial perfusion. We evaluated the usefulness of first-pass CT-myocardial perfusion imaging (MPI) in combination with CCTA for diagnosing coronary artery disease (CAD). A total of 145 patients with suspected CAD were enrolled. We used 64-row multi-detector CT (Definition Flash, Siemens). The same coronary CCTA data were used for first-pass CT-MPI without drug loading. Images were reconstructed by examining the signal densities at diastole as colour maps. Diagnostic accuracy was assessed by comparison with invasive coronary angiography. First-pass CT-MPI in combination with CCTA significantly improved diagnostic performance compared with CCTA alone. With per-vessel analysis, the sensitivity, specificity, positive predictive value and negative predictive value increased from 81% to 85%, 87% to 94%, 63% to 79% and 95% to 96%, respectively. The area under the receiver operating characteristic curve for detecting CAD also increased from 0.84 to 0.89 (p=0.02). First-pass CT-MPI was particularly useful for assessing segments that could not be directly evaluated due to severe calcification and motion artefacts. First-pass CT-MPI has an additional diagnostic value for detecting coronary stenosis, in particular in patients with severe calcification.
    No preview · Article · Apr 2014 · Heart (British Cardiac Society)
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    ABSTRACT: Excess visceral adipose tissue (VAT) is closely associated with the presence of coronary artery plaques that are vulnerable to rupture. Patients with diabetes mellitus (DM) have more VAT than patients without DM, but the extent to which VAT contributes to the characteristics of coronary plaques before and after the development of DM is not fully understood. We retrospectively evaluated 456 patients (60% male, age 64 +/- 16 years) who were suspected to have cardiovascular disease and underwent 64-slice computed tomography angiography (CTA). Seventy-one (16%) patients had vulnerable plaques (CT density < 50 Hounsfield Units, positive remodeling index > 1.05, and adjacent spotty areas of calcification). Patients were divided into tertiles according to the VAT area. There were stepwise increases in noncalcified and vulnerable plaques with increasing tertiles of VAT area in patients without DM, but not in patients with DM. Multivariate analysis showed that a larger VAT area was significantly associated with a higher risk of vulnerable plaque in patients without DM (odds ratio 3.17, 95% confidence interval 1.08-9.31, p = 0.04), but not in patients with DM. The VAT area is associated with the characteristics of coronary plaques on CTA in patients without DM, but not in patients with DM. VAT may be a significant cardiometabolic risk factor that is associated with plaque vulnerability before the development of DM. CTA findings may help to improve risk stratification in such patients.
    Full-text · Article · Mar 2014 · Cardiovascular Diabetology
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    ABSTRACT: A relatively large number of women in their 40s with high-density breasts, in which it can be difficult to detect lesions, are encountered in mammography cancer screenings in Japan. Here, we retrospectively investigated factors related to breast density. Two hundred women (40-49 years old) were examined at the screening center in our hospital. Multivariate analysis showed that factors such as small abdominal circumference, high HDL cholesterol, and no history of childbirth were related to high breast density in women in their 40s undergoing mammography. Other non-mammographic screening methods should be considered in women with abdominal circumferences <76cm, HDL-C >53mg/dl, and no history of childbirth, as there is a strong possibility of these women having high-density breasts that can make lesion detection difficult.
    No preview · Article · Aug 2013 · Acta medica Okayama
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    ABSTRACT: A high mammographic breast density is considered to be a risk factor for breast cancer. However, only a small number of studies on the association between breast density and lifestyle have been performed. A cross-sectional study was performed using a survey with 29 questions on life history and lifestyle. The breast density on mammography was classified into 4 categories following the BI-RADS criteria. The subjects were 522 women with no medical history of breast cancer. The mean age was 53.3 years old. On multivariate analysis, only BMI was a significant factor determining breast density in premenopausal women (parameter estimate, -0.403;p value, 0.0005), and the density decreased as BMI rose. In postmenopausal women, BMI (parameter estimate, -0.196;p value, 0.0143) and number of deliveries (parameter estimate, -0.388;p value, 0.0186) were significant factors determining breast density;breast density decreased as BMI and number of deliveries increased. Only BMI and number of deliveries were identified as factors significantly influencing breast density. BMI was inversely correlated with breast density before and after menopause, whereas the influence of number of deliveries on breast density was significant only in postmenopausal women in their 50 and 60s.
    No preview · Article · Jun 2013 · Acta medica Okayama
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    ABSTRACT: We retrospectively evaluated the accumulation of fluorodeoxy glucose (FDG) in pulmonary malignancies without local recurrence during 2-year follow-up on positron emission tomography (PET)/computed tomography (CT) after radiofrequency ablation (RFA). Thirty tumors in 25 patients were studied (10 non-small cell lung cancers;20 pulmonary metastatic tumors). PET/CT was performed before RFA, 3 months after RFA, and 6 months after RFA. We assessed the FDG accumulation with the maximum standardized uptake value (SUVmax) compared with the diameters of the lesions. The SUVmax had a decreasing tendency in the first 6 months and, at 6 months post-ablation, FDG accumulation was less affected by inflammatory changes than at 3 months post-RFA. The diameter of the ablated lesion exceeded that of the initial tumor at 3 months post-RFA and shrank to pre-ablation dimensions by 6 months post-RFA. SUVmax was more reliable than the size measurements by CT in the first 6 months after RFA, and PET/CT at 6 months post-RFA may be more appropriate for the assessment of FDG accumulation than that at 3 months post-RFA.
    No preview · Article · Apr 2013 · Acta medica Okayama
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    ABSTRACT: The purpose of this study is to evaluate the diagnostic usefulness of magnetic resonance imaging (MRI) characteristics of endometrial polyps in order to differentiate them from other endometrial lesions. MRI was retrospectively reviewed in 40 patients with pathologically proven endometrial polyps. Special attention was paid to the sizes, shapes, margins, internal structures, signal intensities, and post-contrast enhancement patterns. A central fibrous core, intratumoral cysts, and hemorrhage were seen in 30 (75%), 22 (55%), and 14 (35%) patients, respectively. The predominant signal intensity of the lesions showed iso-to slightly low signal intensity relative to the endometrium on T2-weighted images in 36 (90%), low signal intensity on diffusion-weighted images in 32 (80%), and strong or moderate enhancement on enhanced T1-weighted images in 28 patients (70%), respectively. In 32 (80%) patients, the endometrial polyps showed global or partial early enhancement. On dynamic study, rapid enhancement with a persistent strong enhancement pattern was seen in 17 (42.5%) and a gradually increasing enhancement pattern was seen in 17 patients (42.5%). These MRI features can be helpful to distinguish the endometrial polyps from various other endometrial lesions.
    No preview · Article · Dec 2012 · Acta medica Okayama
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    ABSTRACT: Background: We evaluated the safety and efficacy of a bolus injection of landiolol hydrochloride, an ultrashort-acting β1-selective antagonist, as an additional treatment after premedication with an oral β-blocker to reduce heart rate prior to multidetector-row computed tomography (MDCT) coronary angiography (CAG). Methods and results: A total of 458 patients who underwent MDCT CAG were retrospectively enrolled. Image quality and hemodynamic parameters were compared in patients before and after approval of landiolol hydrochloride. If heart rate reduction was insufficient after premedication with an oral β-blocker, a bolus injection of landiolol hydrochloride (n=66) or other drugs (n=30) was used. The percentage of evaluable images per segment in patients after approval of landiolol (99.3%) was greater than that in patients before approval of landiolol (97.4%, P<0.01). Heart rates before scanning in patients receiving landiolol hydrochloride were similar to those receiving other drugs. Heart rate was significantly reduced approximately 5 min after injection of landiolol hydrochloride and increased shortly. No decrease in systolic blood pressure or other adverse effects was observed. Conclusions: Bolus injection of landiolol hydrochloride sufficiently reduced heart rate without significantly reducing systolic blood pressure and produced a high percentage of evaluable images, suggesting that bolus injection of landiolol hydrochloride as an additional pretreatment is feasible in MDCT CAG.
    Full-text · Article · Oct 2012 · Circulation Journal
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    ABSTRACT: The aim of this study was to evaluate the usefulness of F-18 fluorodeoxyglucose (FDG) dual-time-point (DTP) positron emission tomography (PET)/computed tomography (CT) with semiquantitative analyses for the initial staging in patients with malignant lymphoma. Forty-three patients had DTP PET/CT, with 60-min and 2-h scan [n = 8, Hodgkin's lymphoma (HL); n = 12, indolent non-Hodgkin lymphoma (NHL); n = 23, aggressive NHL]. A total of 524 lesions were evaluated (406 lymph nodes and 118 extra-nodal lesions). The maximum standardized uptake value (SUV(max)) on 2-h delayed scan (SUV(2)) was significantly higher than those on 1-h early scan (SUV(1)) for all groups (P < 0.0001 for HL; P < 0.0001 for indolent NHL; P < 0.0001 for aggressive NHL). Significant differences were detected between HL and indolent NHL, between indolent NHL and the aggressive NHL for both SUV(1) and SUV(2) (each P < 0.0001). No significant differences were detected between HL and aggressive NHL for both SUV(1) and SUV(2) (P = 0.6891 for SUV(1); P = 0.8828 for SUV(2)); however, significant differences were detected for the retention index of SUV(max) between these groups (P = 0.0238). DTP F-18 FDG PET/CT with a semiquantitative technique may have the potential to provide the more accurate diagnoses for the staging of malignant lymphoma and the more important role in predicting the histological grades of malignancy compared with single-time-point F-18 FDG-PET scan.
    No preview · Article · Jun 2012 · Annals of Nuclear Medicine
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    ABSTRACT: The aim of the present study was to assess the diagnostic usefulness of Fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in the prediction of local recurrence of malignant lung tumors by analyzing the pre-radiofrequency ablation (RFA) maximal standardized uptake value (SUV(max)). We performed a historical cohort study of consecutive malignant lung tumors treated by RFA from January 2007 to May 2008 at Okayama University Hospital. We selected only lung tumors examined by PET/CT within 90 days before RFA and divided them (10 primary and 29 metastatic) into 3 groups according to their tertiles of SUV(max). We calculated recurrence odds ratios in the medium group and the high group compared to the low group using multivariate logistic analysis. After we examined the relationship between SUV(max) and recurrence in a crude model, we adjusted for some factors. Tumors with higher SUV(max) showed higher recurrence odds ratios (medium group; 1.84, high group; 4.14, respectively). The tumor size also increased the recurrence odds ratio (2.67); we thought this was mainly due to selection bias because we excluded tumors less than 10mm in diameter. This study demonstrated the pre-RFA SUV(max) in PET/CT may be a prognostic factor for local recurrence of malignant lung tumors.
    No preview · Article · Dec 2011 · Acta medica Okayama
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    ABSTRACT: The aim of this study is to evaluate whether thallium-201 (201-Tl) scintigraphy can differentiate malignant from benign soft-tissue tumors. Between April 1995 and December 2005, 192 patients with soft-tissue tumors (85 malignant and 107 benign) underwent 201-Tl scintigraphy before treatment. Isotope uptake was used as a proxy for tumor-to-background ratio (TBR). The accuracy of TBR on early and delayed imaging was evaluated using the Mann-Whitney U and χ(2) tests. There was a statistically significant difference in mean TBR on early and delayed imaging of malignant and benign soft-tissue tumors (124% ± 109% vs. 22% ± 42%, and 82% ± 83% vs. 12% ± 25%, P < 0.0001). A TBR cutoff of 20% indicated the probability of malignancy on early and delayed imaging (82% sensitivity and 77% specificity; 82% sensitivity and 84% specificity, P < 0.0001). Well-differentiated liposarcomas showed low isotope accumulation, while pigmented villonodular synovitis and giant cell tumors of the tendon sheath showed high isotope accumulation. Thallium-201 scintigraphy can distinguish malignant from benign tumors with relatively high accuracy. With the exception of low grade liposarcomas and locally aggressive benign tumors, 201-Tl scintigraphy may be an effective diagnostic modality to differentiate malignant from benign soft-tissue tumors.
    No preview · Article · Nov 2011 · Clinical nuclear medicine
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    ABSTRACT: To determine the effectiveness of living-donor lobar lung transplantation (LDLLT), it is necessary to predict the recipient's postoperative lung function. Traditionally, Date's formula, also called the segmental ratio, has used the number of lung segments to estimate the forced vital capacity (FVC) of grafts in LDLLT. To provide a more precise estimate of graft FVC, we calculated the volumes of the lower lobe and total lung using three-dimensional computed tomography (3D-CT) and the volume ratio between them. We calculated the volume ratio in 52 donors and tested the difference between the segmental volume ratios with a one-tailed t-test. We also calculated the predicted graft FVC in 21 LDLLTs using the segmental ratio pFVC(c) and the volume ratio pFVC(v), and then found the Pearson's correlation coefficients for both pFVC(c) and pFVC(v) with the recipients' actual FVC (rFVC) measured spirometrically 6 months after surgery. Significant differences were found between the segmental ratio and the average volume ratio for both sides (right, p=0.03;left, p=0.0003). Both pFVC(c) and pFVC(v) correlated significantly with rFVC at 6 months after surgery (p=0.007 and 0.006). Both the conventional and the volumetric methods provided FVC predictions that correlated significantly with measured postoperative FVC.
    No preview · Article · Aug 2011 · Acta medica Okayama
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    ABSTRACT: The aim of this study was to evaluate the local efficacy of I-131 for F-18 fluorodeoxyglucose positron emission tomography (FDG PET)-positive lesions. Whole-body FDG PET/CT was performed on 37 patients (55 cases: 16 men, 21 women; age range: 24-82 years; mean age ± standard deviation: 60.5 ± 16.0 years) with differentiated thyroid cancer after total thyroidectomy. The metastatic or recurrent lesions were divided into 5 categories: primary tumor bed, lymph node, lung, bone, and other. The well-defined lesions were measured on CT, and the sizes were compared before and after radioactive iodine therapy. The analysis was performed on 37 patients with 44 lesions (lymph node:24, lung:16, bone:4). Sixteen lesions (70%) were increased and 7 (30%) showed no change or reduction when there was positive accumulation on FDG PET/CT and negative accumulation on I-131 (F(+)I(-)) group. In the positive accumulation for both FDG PET/CT and I-131 (F(+)I(+)) group, 5 lesions (63%) were increased and 3 (37%) showed no change or reduction. There was no significant difference for the tendency to increase in size between the F(+)I(-) and the F(+)I(+) groups. Lesions which show positive accumulations on FDG PET/CT have a greater tendency to increase in size. FDG-avid lesions are resistant to radioactive iodine therapy with or without I-131 uptake.
    No preview · Article · Feb 2011 · Clinical nuclear medicine