Masatoyo Nakajo

Kagoshima University, Kagosima, Kagoshima, Japan

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Publications (28)69.5 Total impact

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    ABSTRACT: Purpose: The purpose of this study is to compare diagnostic performances of (18)F-fluorodeoxyglucose (FDG) visual score, maximum standardized uptake value (SUVmax), ratio of adrenal SUVmax to liver SUVmax (A/L SUVmax), apparent diffusion coefficient (ADC) from diffusion-weighted imaging, and SUVmax/ADC ratio to differentiate adrenal pheochromocytoma from other benign tumors. Methods: Eleven pheochromocytomas and 22 other benign tumors in 30 patients were included. FDG-based indices, ADC, and SUVmax/ADC ratio were compared between groups using the Mann-Whitney U test, and sensitivity, specificity, accuracy, and area under the curve (AUC) for diagnosing pheochromocytoma by receiver operating characteristic analyses. The correlation between SUVmax and ADC was analyzed using the Spearman's rank test. Results: Pheochromocytoma showed significantly higher visual score (2.8 ± 0.4 vs. 1.3 ± 0.9), SUVmax (11.0 ± 8.9 vs. 3.2 ± 1.4), A/L SUVmax ratio (3.96 ± 3.48 vs. 0.96 ± 0.51), and SUVmax/ADC ratio (10.6 ± 8.09 vs. 2.28 ± 0.98) (each P < 0.001) and significantly lower ADC (1.08 ± 0.23 × 10(-3) mm(2)/s vs. 1.43 ± 0.29 × 10(-3) mm(2)/s, P = 0.003) than other benign tumors. Sensitivity, specificity, and accuracy for diagnosing pheochromocytoma were 100, 73, and 82% for visual score, 100, 86, and 91% for both SUVmax and A/L SUVmax ratio, and 64, 100, and 88% for ADC and 82, 95, and 91% for SUVmax/ADC ratio. No significant differences in AUC were found between FDG-based indices, ADC, and SUVmax/ADC ratio. A significant negative correlation was noted between SUVmax and ADC (ρ = -0.36, P = 0.039). Conclusion: FDG-based indices and ADC appear comparably useful for differentiating pheochromocytoma from other benign adrenal tumors.
    Abdominal Imaging 11/2014; · 1.91 Impact Factor
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    ABSTRACT: Radioiodide is commonly used to diagnose and treat hyperthyroidism and thyroid carcinoma. However, we could not find any experimental data that strictly compared the biodistribution and thyroid uptake of radioactive iodide between the oral and intravenous (iv) routes with time. This prompted us to compare (123)I biodistribution and thyroid uptake to clarify the differences between oral and iv bolus administration in rats.
    Annals of Nuclear Medicine 10/2014; · 1.41 Impact Factor
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    ABSTRACT: Effective treatments for malignant neuroendocrine tumors are under development. While iodine-131 metaiodobenzylguanidine ((131)I-MIBG) radiotherapy has been used in the treatment of malignant neuroendocrine tumors, there are few studies evaluating its therapeutic effects and safety in a multicenter cohort. In the current study, we sought to evaluate the effects and safety of (131)I-MIBG therapy for conditions including malignant pheochromocytoma and paraganglioma within a multicenter cohort. Forty-eight malignant neuroendocrine tumors (37 pheochromocytoma and 11 paraganglioma) from four centers underwent clinical (131)I-MIBG radiotherapy. The tumor responses were observed before and 3 to 6 months after the (131)I-MIBG radiotherapy in accordance with RECIST criteria. We also evaluated the data for any adverse effects. The four centers performed a total of 87 (131)I-MIBG treatments on 48 patients between January 2000 and March 2009. Of the treatments, 65 were evaluable using RECIST criteria. One partial response (PR), 40 stable disease (SD), and 9 progressive disease (PD) in malignant pheochromocytoma were observed after each treatment. Fourteen SD and one PD were observed in paraganglioma. Patients with normal hypertension (systolic blood pressure (BP) > 130 mmHg) showed significantly reduced systolic BP after the initial follow-up (n=10, 138.1±8.2 to 129.5±13.5 mmHg, P=0.03). In adult neuroendocrine tumors with a treatment-basis analysis, there were side effects following 41 treatments (47.1%) and most of them (90.2%) were minor. In this multicenter registry, PR or SD was achieved in 84.6% of the treatment occasions in adult neuroendocrine tumors through (131)I-MIBG radiotherapy. This indicated that most of the (131)I-MIBG radiotherapy was performed safely without significant side effects.
    Endocrine Journal 09/2014; · 2.23 Impact Factor
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    ABSTRACT: To examine correlations of (18)F-fluorothymidine (FLT) uptake with pathological tumour size and immunohistochemical Ki-67, and thymidine kinase 1 (TK-1) expressions in primary and metastatic node colorectal cancer foci.
    European radiology. 08/2014;
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    ABSTRACT: PURPOSE To examine whether the intratumoral heterogeneity of FDG uptake on PET/CT can be helpful to discriminate between primary benign and malignant musculoskeletal (MS) tumors. METHOD AND MATERIALS The study population consisted of 63 patients who underwent PET/CT examinations before therapy for primary MS tumors. The intratumoral heterogeneity was evaluated by the calculated cumulative standardized uptake value (SUV)-volume histograms which were describing % of total tumor volume above % threshold of maximum SUV (SUVmax). Percent tumor areas above a threshold from 0 to 100% of the SUVmax were plotted and the area under curve of the cumulative SUV histograms (AUC-CSH) was used as a heterogeneity index, with lower values corresponded with increased heterogeneity. The differences in the SUVmax and AUC-CSH between benign and malignant tumors were examined using the Mann-Whitney’s U test. To examine the applicability of SUVmax and AUC-CSH for discrimination between benign and malignant tumors, receiver operating characteristic (ROC) analyses were conducted. RESULTS There were 35 benign (8 schwannomas, 5 giant cell tumors and 22 others) and 28 malignant (11 MFHs, 4 liposarcomas, 4 myxofirosarcomas and 9 others) tumors. There was no significant difference in the SUVmax between benign and malignant tumors (6.9 ± 4.4 vs. 9.2 ± 6.0, P=0.17). However, the AUC-CSH was significantly lower for malignant tumors than for benign tumors (0.43 ± 0.14 vs. 0.52 ±0.10, P=0.004), and malignant tumors exhibited more heterogeneous uptake than benign tumors. The optimal threshold values were >6.9 for SUVmax and ≤0.42 for AUC-CSH to diagnose malignant tumors. The sensitivity, specificity, accuracy and area under the ROC curve (AUC-ROC) were 61% (17/28), 66% (23/35), 63% (40/63) and 0.60 for SUVmax, and 61% (17/28), 89% (31/35), 76% (48/63) and 0.71 for AUC-CSH, which was superior to SUVmax in the AUC-ROC (P=0.018). CONCLUSION Primary malignant MS tumors exhibited more heterogeneous intrarumoral uptake than primary benign ones. Evaluation of the intratumoral heterogeneity of FDG uptake may be more helpful than SUVmax in discrimination between primary benign and malignant MS tumors. CLINICAL RELEVANCE/APPLICATION Evaluation of the intratumoral heterogeneity of FDG uptake may help in discrimination between primary benign and malignant musculoskeletal tumors.
    Radiological Society of North America 2013 Scientific Assembly and Annual Meeting; 12/2013
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    ABSTRACT: Transcatheter arterial embolization (TAE) with absolute ethanol is widely accepted as a therapeutic procedure for renal angiomyolipoma (AML). We aim to evaluate the split renal function before and after AE for renal AML by using 99m-technetium ((99m)Tc)-mercaptoacetyltriglycine 3 (MAG3) renography. This study was approved by the Institutional Review Board. The study population comprised 11 renal AML patients (three males, eight females, age 55.1 ± 13.8 years, AML in eight right and three left kidneys) who received unilateral renal TAE with absolute ethanol from April 2002 to January 2013. Blood renal function (i.e. serum creatinine and estimated glomerular filtration rate [eGFR] and split effective renal plasma flow [ERPF]) calculated on (99m)Tc-MAG3 renography was compared before and within 1 week after renal AE. Statistical analysis was calculated using Wilcoxon signed-ranked test. TAE for renal AML was technically successful in all patients. Serum creatinine and eGFR did not change before and after TAE. ERPF on the embolized kidney did not change before (127.3 ± 60.8 ml/min) and after (127.6 ± 47.4 ml/min) TAE (p = 0.9726). ERPF on the nonembolized kidney showed a statistically significant increase before (152.5 ± 46.8 ml/min) and within 1 week after (169.1 ± 41.5 ml/min) TAE (p = 0.0093 and p < 0.05, respectively). TAE for renal AML may not induce renal dysfunction on the embolized kidney and may immediately increase the renal blood flow of the nonembolized kidney.
    CardioVascular and Interventional Radiology 11/2013; · 2.09 Impact Factor
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    ABSTRACT: PURPOSE: To examine the diagnostic performance of (18)F-fluorothymidine (FLT) PET/CT in primary and metastatic lymph node colorectal cancer foci in comparison with (18)F-fluorodeoxyglucose (FDG) PET/CT. METHODS: The study population comprised 28 patients with 30 newly diagnosed colorectal cancers who underwent surgical resection of the primary lesion and regional lymph nodes after both FLT and FDG PET/CT. The associations between SUVmax levels and pathological factors were evaluated using the Mann-Whitney U or Kruskal-Wallis test. Differences in diagnostic indexes for detecting nodal metastasis between the two tracers were estimated using the McNemar exact or χ (2) test. RESULTS: All 30 primary cancers (43.0 ± 20.0 mm, range 14 - 85 mm) were visualized by both tracers, but none of the FLT SUVmax values exceeded the FDG SUVmax values in any of the primary cancers (6.6 ± 2.4 vs. 13.6 ± 5.8, p < 0.001). The sensitivity, specificity and accuracy for detecting nodal metastasis were 41 % (15/37), 98.8 % (493/499) and 94.8 % (508/536) for FDG PET/CT, and 32 % (12/37), 98.8 % (493/499) and 94.2 % (505/536) for FLT PET/CT, respectively. The sensitivity (p = 0.45), specificity (p = 0.68) and accuracy (p = 0.58) were not different between the tracers. Nodal uptake of FLT and FDG was discordant in 7 (19 %) of 37 metastatic nodes. There were ten concordant true-positive nodes of which six showed higher FDG SUVmax and four showed higher FLT SUVmax, but the difference between FDG and FLT SUVmax was not significant (5.56 ± 3.55 and 3.62 ± 1.45, respectively; p = 0.22). CONCLUSION: FLT has the same potential as FDG in PET/CT for the diagnosis of primary and nodal foci of colorectal cancer despite significantly lower FLT uptake in primary foci.
    European Journal of Nuclear Medicine 05/2013; · 4.53 Impact Factor
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    ABSTRACT: Purpose:To compare positron emission tomography (PET)/computed tomography (CT) studies performed with the glucose analog fluorine 18 (18F) fluorodeoxyglucose (FDG) and the cell proliferation tracer 18F fluorothymidine (FLT) in the diagnosis of metastases from postoperative differentiated thyroid cancer.Materials and Methods:The institutional ethics review board approved this prospective study. From March 2010 to February 2012, 20 patients (mean age, 53 years; age range, 22-79 years) with postoperative differentiated thyroid cancer underwent both FDG and FLT PET/CT as a staging work-up before radioiodine therapy. In each patient, 28 anatomic areas were set and analyzed for lymph node and distant metastases. The McNemar exact or χ2 test was used to examine differences in diagnostic indexes in the detection of lymph node and distant metastases between both tracer PET/CT studies.Results:There were 34 lymph node metastases and/or 73 distant metastases (70 metastases in lung and one each in bone, nasopharynx, and brain) in 13 patients. At patient-based analysis, the sensitivity, specificity, and accuracy were 92% (12 of 13 patients), 86% (six of seven patients), and 90% (18 of 20 patients), respectively, for FDG PET/CT and 69% (nine of 13 patients), 29% (two of seven patients), and 55% (11 of 20 patients) for FLT PET/CT. The accuracy of FDG PET/CT was significantly better than that of FLT PET/CT (P = .023). At lesion-based analysis, the sensitivity, specificity, and accuracy for diagnosing lymph node metastases were 85% (29 of 34 lesions), 99.6% (245 of 246 lesions), and 97.9% (274 of 280 lesions), respectively, for FDG PET/CT and 50% (17 of 34 lesions), 90.7% (223 of 246 lesions), and 85.7% (240 of 280 lesions) for FLT PET/CT. The sensitivity, specificity, and accuracy for diagnosing distant metastases were 45% (33 of 73 lesions), 100% (207 of 207 lesions), and 85.7% (240 of 280 lesions), respectively, for FDG PET/CT and 6.8% (five of 73 lesions), 100% (207 of 207 lesions), and 75.7% (212 of 280 lesions) for FLT PET/CT. The sensitivity (P = .002), specificity (P < .001), and accuracy (P < .001) of FDG PET/CT in the diagnosis of lymph node metastases were superior to those of FLT PET, as were the sensitivity (P < .001) and accuracy (P < .001) in the diagnosis of distant metastases.Conclusion:FDG PET/CT is superior to FLT PET/CT in the diagnosis of postoperative differentiated thyroid cancer lymph node and distant metastases. Thus, FDG PET/CT is more suitable than FLT PET/CT for examining recurrence of postoperative differentiated thyroid cancer.© RSNA, 2013Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13121546/-/DC1.
    Radiology 03/2013; · 6.34 Impact Factor
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    ABSTRACT: We report a 58-year-old man whose incidentally discovered papillary thyroid carcinoma in the left lobe showed high FDG and low FLT uptake on PET/CT. The SUVmax was 19.7 for FDG and 3.0 for FLT. The Ki-67 labeling index of the tumor was 1.9%. Thus, the low FLT uptake might be attributed to the low proliferative activity of this cancer.
    Clinical nuclear medicine 06/2012; 37(6):607-8. · 3.92 Impact Factor
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    ABSTRACT: To compare primary tumor (18)F-fluorodeoxyglucose (FDG) maximum standardized uptake value (SUV(max)) and diffusion-weighted imaging (DWI) apparent diffusion coefficient (ADC) obtained in the same patients with head and neck squamous cell carcinoma (HNSCC) to clarify the prognostic significance of both indexes. The study population comprised 26 patients with HNSCC visible on both pretreatment FDG PET/CT and DWI. Correlation between SUV(max) and ADC (b values; 0 and 800 seconds/mm(2)) was analyzed by the Spearman's rank test. Disease-free survival (DFS) was calculated by the Kaplan-Meier method. Prognostic significance was assessed by the long-rank test and Cox proportional hazards analysis. SUV(max) and ADC correlated significantly and negatively (ρ = -0.566, P = 0.005). High (>12.1) SUV(max) (P < 0.001), low (≤ 0.88) ADC (P = 0.009), high (T3-4) T stage (P = 0.030), and high (N2-3) N stage (P = 0.007) were significant in predicting poor 2-year DFS. The accuracy for predicting disease events was 81% (21/26) for SUV(max) (>12.1) and 73% (19/26) for ADC(≤ 0.88) without significant difference between them (P = 0.52). Disease event hazards ratios for significant unadjusted SUV(max) (P = 0.015) and ADC (P = 0.039) remained significant when adjusted for other dichotomized clinical covariates (SUV(max); P = 0.009-0.039, ADC; P = 0.017-0.037) except SUV(max) for ADC and ADC for SUV(max) and T stage. These results suggest that pretreatment primary tumor SUV(max) and ADC correlate significantly and negatively and both may have similar potential to predict DFS or disease events of HNSCC.
    Clinical nuclear medicine 05/2012; 37(5):475-80. · 3.92 Impact Factor
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    ABSTRACT: We report a case of multiple benign metastasizing leiomyoma (BML) lung nodules showing faint or non-avid uptake of F-18 fluorodeoxyglucose (FDG) (respective 1-hour early and 2-hour delayed maximum standardized uptake values; 1.3 or less and 1.2 or less) in a 50-year-old woman with a history of hysterectomy for uterine leiomyoma at the age of 38 years. When multiple lung nodules show faint or non-avid FDG uptake in a patient with a history of hysterectomy for uterine leiomyoma, BML should be included in the differential diagnosis.
    Acta radiologica short reports. 01/2012; 1(3).
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    ABSTRACT: To evaluate (18)F-fluorodeoxyglucose (FDG) uptake to predict the malignant nature and analyze the correlation between FDG uptake and expression of glucose transporter 1 (Glut-1) and hexokinase II (HK-II) in thymic epithelial tumors. Eleven patients with a thymic epithelial tumor who underwent FDG PET/CT before therapy were reviewed. The thymic tumors were classified by the WHO histological classification and Masaoka clinical staging. Comparison of maximum standardized uptake value (SUV(max)) of the lesion was made between the low-risk (Type A, AB and B1) and high-risk {Type B2, B3 and C (thymic cancer)} groups and among clinical stages. Expression of Glut-1 and HK-II was analyzed immunohistochemically. All 11 tumors showed FDG uptake visually. SUV(max) was significantly higher in the high-risk group (n=5, 5.24 ± 2.44) than the low-risk group (n=6, 3.05 ± 0.55) (P=0.008). Staining scores of both Glut-1 and HK-II were significantly higher in the high-risk group than in the low-risk group (Glut1: P=0.034 and HK-II: P=0.036). There were no significant differences in SUV(max) (P=0.11), Glut-1 (P=0.35) and HK-II scores (P=0.29) among clinical stages. SUV(max) was significantly correlated to each of the staining scores of Glut-1 (ρ=0.68, P=0.031) and HK-II (ρ=0.72, P=0.024). These preliminary results support the previously published view that SUV(max) may be useful to predict the malignant nature of thymic epitherial tumors and suggest that the degree of FDG uptake in the thymic epitherial tumors is closely related to the amount of Glut-1 and HK-II in the tumor.
    European journal of radiology 01/2012; 81(1):146-51. · 2.65 Impact Factor
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    ABSTRACT: Black adrenal adenoma (BAA) is an adrenal adenoma which contains lipofuscin and has a black or brown appearance. Preoperative diagnosis of BAA is difficult because it is diagnosed by pathologic findings. We report a case of an incidentally discovered non-hyperfunctioning BAA in the left adrenal gland of a 58-year-old man. It showed an oval lipid-poor mass, 3 cm × 2 cm in size on computed tomography (CT) and magnetic resonance imaging (MRI), no avid uptake of (131)I-norcholesterol and (123)I-meta-iodobenzylguanidine (MIBG) on scintigraphy, and intense avid uptake of (18)F-fluorodeoxyglucose (FDG) on positron emission tomography-CT (PET/CT). FDG PET/CT showed that it was a hypermetabolic lesion, more intense than the activity of the liver, and the maximum standardized uptake value was 5.6 on 1-h early imaging and 8.3 on 2-h delayed imaging, suggesting a malignant tumor. BAA is a clinically rare benign adrenal adenoma, but it should be kept in mind that BAA may exhibit false-positive results for malignancy or inconclusive results for benignity with modern imaging modalities including CT, MRI, adrenal scintigraphy with radiolabelled cholesterol and radiolabelled MIBG, and FDG-PET like this case.
    Annals of Nuclear Medicine 09/2011; 25(10):812-7. · 1.41 Impact Factor
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    ABSTRACT: To correlate primary oesophageal squamous cell carcinoma (SCC) (18)F-fluoro-deoxyglucose (FDG) uptake with pathological factors and examine its significance regarding choice of therapy. We retrospectively examined the factors affecting visible and non-visible FDG uptake in 37 primary lesions in 32 oesophageal SCC patients who underwent PET/CT before oesophagectomy or endoscopic submucosal dissection (ESD). We divided the lesions into pathological depth invasion ≥sm2 oesophagectomy (n = 18) and ≤sm1 ESD (n = 19) indicated groups and compared the diagnostic accuracy of FDG-PET with that of endoscopic ultrasound (EUS) performed for 23 superficial lesions to discriminate between these groups. There were 17 visible and 20 non-visible lesions. The lesion visibility was significantly higher in the larger (≥40 mm), non-flat type, more deeply invaded, positive vascular invasion (P < 0.001 each), positive nodal metastasis (P = 0.04) and higher Glut-1 score (P = 0.005) tumour groups. When the visible and non-visible lesions indicated a need for oesophagectomy and ESD respectively, the sensitivity, specificity and accuracy of oesophagectomy were 94% (17/18), 100% (19/19) and 97% (36/37) and those of EUS were 75% (3/4), 79% (15/19) and 78% (18/23) respectively. Primary lesion FDG visibility can be one of the indicators for choosing between oesophagectomy and ESD for resectable oesophageal SCCs.
    European Radiology 07/2011; 21(11):2396-407. · 4.34 Impact Factor
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    ABSTRACT: To correlate both primary lesion (18)F-fluorodeoxyglucose (FDG) maximum standardized uptake value (SUVmax) and diffusion-weighted imaging (DWI) apparent diffusion coefficient (ADC) with clinicopathological prognostic factors and compare the prognostic value of these indexes in breast cancer. The study population consisted of 44 patients with 44 breast cancers visible on both preoperative FDG PET/CT and DWI images. The breast cancers included 9 ductal carcinoma in situ (DCIS) and 35 invasive ductal carcinomas (IDC). The relationships between both SUVmax and ADC and clinicopathological prognostic factors were evaluated by univariate and multivariate regression analysis and the degree of correlation was determined by Spearman's rank test. The patients were divided into a better prognosis group (n = 24) and a worse prognosis group (n = 20) based upon invasiveness (DCIS or IDC) and upon their prognostic group (good, moderate or poor) determined from the modified Nottingham prognostic index. Their prognostic values were examined by receiver operating characteristic analysis. Both SUVmax and ADC were significantly associated (p<0.05) with histological grade (independently), nodal status and vascular invasion. Significant associations were also noted between SUVmax and tumour size (independently), oestrogen receptor status and human epidermal growth factor receptor-2 status, and between ADC and invasiveness. SUVmax and ADC were negatively correlated (ρ=-0.486, p = 0.001) and positively and negatively associated with increasing of histological grade, respectively. The threshold values for predicting a worse prognosis were ≥4.2 for SUVmax (with a sensitivity, specificity and accuracy of 80%, 75% and 77%, respectively) and ≤0.98 for ADC (with a sensitivity, specificity and accuracy of 90%, 67% and 77%, respectively). SUVmax and ADC correlated with several of pathological prognostic factors and both indexes may have the same potential for predicting the prognosis of breast cancer.
    European Journal of Nuclear Medicine 11/2010; 37(11):2011-20. · 4.53 Impact Factor
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    ABSTRACT: We experienced a case of a focal pulmonary F-18 fluoro-2-deoxy-D-glucose (FDG) uptake without pulmonary computed tomography (CT) abnormality probably due to the urine FDG in the upper pole calyx of the left kidney. A 76-year-old male patient was referred for evaluation of the postoperative right lung cancer. Positron emission tomography/CT was performed 1 hour after intravenous injection of FDG and showed a small focus of increased uptake in the left lower lung field accompanying no abnormality in the corresponding lung CT images. The lung uptake was not noted in repeated positron emission tomography/CT images taken after 1 hour, suggesting misplacement of the left renal upper calyx into the lower lung.
    Clinical nuclear medicine 09/2010; 35(9):713-6. · 3.92 Impact Factor
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    ABSTRACT: We report a case of a 38-year-old man with a mesenchymal hamartoma of the liver (MHL) in which FDG did not accumulate intensely. The MHL was an ill-defined multicystic tumor on computed tomography and magnetic resonance imaging. It was an ill-defined mass with multihypometabolic areas on FDG PET/CT. When an ill-defined liver mass with multihypometabolic areas is observed on FDG PET/CT, MHL should be included in the differential diagnosis of liver tumors.
    Clinical nuclear medicine 06/2009; 34(5):327-9. · 3.92 Impact Factor
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    ABSTRACT: The objective of our study was to clarify which clinicopathologic factors affect the FDG PET visibility of colorectal polyps. We used statistical methods in a retrospective examination of factors affecting the visibility of 87 colorectal polyps in 50 patients who underwent PET for cancer screening. PET depicted 37% (32/87) of polyps. Univariate analysis revealed significant associations between polyp visibility and polyp size, histologic grade (p < 0.001 each), type (p = 0.004), and patient age (p = 0.049) but not sex or polyp location. The visualization rate increased with increases in polyp size (< or = 5 mm, 12%; 6-10 mm, 47%; > or = 11 mm, 59%) and severity of dysplasia (indefinite or low-grade dysplasia, 13%; high-grade dysplasia, 67%; polyp with early carcinoma, 75%) and was higher for pedunculated polyps (59%) than for nonpedunculated polyps (27%). Multivariate analysis showed that histologic grade was the strongest factor (p < 0.001) among three independent factors (histologic grade, type, and age). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for visualization of high-grade or early carcinoma polyps to be removed were 71%, 87%, 78%, 82%, and 80%. Maximum standardized uptake values did not differ significantly between visualized polyps with indefinite or low-grade dysplasia and visualized polyps with high-grade dysplasia or early carcinoma. Histologic grade is the strongest independent factor in FDG PET visibility of colorectal polyps. FDG PET visibility may be helpful for predicting whether a polyp should be removed or observed. FDG PET findings also may suggest the need to alter the treatment of patients with colorectal polyps.
    American Journal of Roentgenology 04/2009; 192(3):754-60. · 2.90 Impact Factor
  • Clinical nuclear medicine 08/2008; 33(8):579-81. · 3.92 Impact Factor
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    ABSTRACT: The aim of this study was to evaluate retrospectively the efficacy of whole-body (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) for autoimmune pancreatitis (AIP) and associated extrapancreatic autoimmune lesions. Whole-body FDG-PET or PET/computed tomography (CT) findings were reviewed in six patients with AIP. The initial PET scans were performed 1 h and 2 h after FDG injection in all six patients. Follow-up PET scans were performed during or following steroid therapy in five patients and in one patient who did not have steroid therapy. The initial PET scans revealed intense FDG uptake by AIP in all six patients. The maximum standardized uptake value (SUVmax) increased in four patients and was stable in two patients. The intense uptake in the pancreas disappeared during or following steroid therapy in five patients and in one patient who showed spontaneous remission of AIP. Abnormal FDG uptake by extrapancreatic autoimmune diseases was observed in five of the six patients: sclerosing sialadenitis (n = 5), lymphadenopathy (n = 5), retroperitoneal fibrosis (n = 2), interstitial nephritis (n = 2) and sclerosing cholecystitis (n = 1). Abnormal FDG uptake disappeared in the salivary glands (n = 4), lymph nodes (n = 4), retroperitoneum (n = 2), kidneys (n = 1) and gallbladder (n = 1) during or following steroid therapy and remained in the salivary glands and lymph nodes of a spontaneous remission patient. These results suggest that whole-body FDG-PET may be useful for detecting AIP and associated extrapancreatic autoimmune lesions and for monitoring their disease activity but that dual time point imaging may not be useful for differentiating malignancy from AIP.
    European journal of nuclear medicine and molecular imaging 01/2008; 34(12):2088-95. · 5.11 Impact Factor