Hideki Otsuka

The University of Tokushima, Tokusima, Tokushima, Japan

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Publications (34)17.9 Total impact

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    ABSTRACT: Positron emission tomography-computed tomography (PET-CT) with [18F] fluorodeoxyglucose (FDG) has recently been applied for evaluating tumor response to anticancer therapy. The aim of the present study was to evaluate the utility of FDG PET-CT in monitoring non-invasively and repeatedly the inhibitory effect of cisplatin (CDDP) on an orthotopic lung cancer model. Validation of in vivo FDG uptake in human lung cancer Ma44-3 cell line in an orthotopic SCID mouse model was carried out. Next, we assessed the use of FDG PET-CT to monitor the response of orthotopic lung cancer to the anticancer effect of CDDP. SCID mice were divided into the CDDP group (7 mg/kg single dose intraperitoneally) and the control group. Tumor volume and maximal standardized uptake value (SUV max) were calculated for all mice. All mice were sacrificed for histopathologic analysis. Validation of FDG PET-CT showed that tumor volume and SUV max were significantly correlated with postmortem tumor length measured in specimens (P=0.023) and (P=0.012), respectively, and there was a significant correlation between SUV max and tumor volume (P=0.048). Response monitoring showed that significant growth inhibition by CDDP in the form of SUV max of the CDDP group was significantly lower than that of the control group on day 8 (P=0.02) and on day 13 (P=0.003). Tumor volume of the CDDP group was significantly lower than that of the control group on day 13 (P=0.03). The present study supports using FDG PET-CT in monitoring tumor progression and therapeutic response of lung cancer in an orthotopic model non‑invasively and repeatedly.
    Oncology Reports 03/2014; · 2.30 Impact Factor
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    ABSTRACT: Introduction The utility of FDG PET/CT for the detection and evaluation of invasive ductal carcinoma has been widely reported, but a few studies have assessed the utility of FDG PET/CT to detect malignancy in a variety of pancreatic lesions other than invasive ductal carcinoma. Purpose To compare the diagnostic performance of visual estimation with the semi-quantitative scores of FDG PET/CT for detecting malignancy in a variety of pancreatic lesions other than invasive ductal carcinoma. Material and Methods Images of pathologically proven pancreatic lesions from 32 patients were retrospectively evaluated: 14 benign lesions, 7 borderline (low malignant) lesions, and 11 malignant lesions. The average scores from visual estimation by the two observers were compared to two semi-quantitative analyses of FDG uptake in the lesions, namely the maximum standardized uptake value (SUVmax) and mean standardized uptake value (SUVmean). Results Visual analysis value, SUVmax and SUVmean were 0.33±0.21, 1.8±0.7 and 1.5±0.7 for the benign lesions, 0.70±0.28, 5.0±2.6 and 3.1±1.7 for the borderline lesions, and 0.73±0.18, 4.7±2.5 and 3.2±1.6 for the malignant lesions, respectively. Receiver operating characteristic analysis revealed the areas under the curves for detecting non-benign (malignant or borderline) lesions through visual analysis, SUVmax, and SUVmean were 0.914, 0.954, and 0.875, respectively. Conclusion For a variety of pancreatic lesions other than invasive ductal carcinoma, visual analysis and semi-quantitative analyses all showed strong diagnostic performance. However, semi-quantitative analysis with SUVmax proved to be the most effective method for detecting non-benign pancreatic lesions. J. Med. Invest. 61: 171-179, February, 2014.
    The Journal of Medical Investigation 01/2014; 61(1.2):171-9.
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    ABSTRACT: Purpose: The purpose of this study was to evaluate the impact of a cyclotron on small-animal PET equipment installed directly above the cyclotron. Methods: The cyclotron equipment was HM-12, which has two targets, and the PET/CT equipment was Inveon. The equipment was installed in conformity to Japanese law and regulations. Before installation of the PET/CT equipment, the radiation dose, radio waves, and static and fluctuating magnetic fields were measured at the position where it would be placed, both when the cyclotron was in use and when it was not in use. After installation of the PET/CT, natural background and emission counts were measured at the same place under the same conditions. Results: An increase of radiation dose was observed when the target nearest the PET equipment was used. There were no distinct effects of radio waves or static and fluctuating magnetic fields. A significant increase of emission counts, approximately 300 cpm, was observed when the nearest target was used. Conclusions: Though radio waves and static and fluctuating magnetic fields generated by running cyclotron had no influence, a significant increase in emission count was observed. Careful attention should be paid to this influence when very low-radioactivity PET measurements are done. J. Med. Invest. 61: 46-52, February, 2014.
    The Journal of Medical Investigation 01/2014; 61(1.2):46-52.
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    ABSTRACT: Purpose: The purpose of this study was to evaluate the physiological uptake pattern of (18)F-FDG in the left ventricular myocardium of patients under preparation for tumor FDG-PET. Patients and Methods: We enrolled 188 patients without cardiac disease. The accumulation patterns were classified as either 'none', 'diffuse', 'focal' or 'focal on diffuse'. When a focal uptake was only observed on the basal wall, then the patterns were classified as having either a 'ring', 'over half' or 'spot' uptake. Results: The frequencies of the myocardial FDG uptake patterns were as follows: none, n=52 (27.7%); diffuse, n=63 (33.5%); focal on diffuse, n=40 (21.3%) and focal, n=33 (17.6%). The age, blood glucose level, weight and dose of FDG did not differ significantly for each pattern. The focal and focal on diffuse patterns were seen in 73 patients, and 65 patients had a focal uptake only on the basal wall; ring uptake in 29 patients, over half in 20 and spot uptake in 16 patients. Conclusions: The physiological myocardial uptake showed several patterns. Focal uptake was often seen in patients with cardiac disease, but it did not always indicate an abnormal finding when the accumulation was only on the basal wall. J. Med. Invest. 61: 53-58, February, 2014.
    The Journal of Medical Investigation 01/2014; 61(1.2):53-8.
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    ABSTRACT: Purpose: Our purposes were to establish suitable conditions for proton magnetic resonance spectroscopy (MRS) to measure dynamic changes in alcohol concentration in the human brain, to evaluate these changes, and to compare the findings with data from analysis of breath vapor and blood samples. Materials and Methods: We evaluated 4 healthy volunteers (mean age 26.5 years; 3 males, one female) with no neurological findings. All studies were performed with 3-tesla clinical equipment using an 8-channel head coil. We applied our modified single-voxel point-resolved spectroscopy (PRESS) sequence. Continuous measurements of MRS, breath vapor, and blood samples were conducted before and after the subjects drank alcohol with a light meal. The obtained spectra were quantified by LCModel Ver. 6.1, and the accuracy of the MRS measurements was estimated using the estimated standard deviation expressed in percentage (%SD) as a criterion. Results: Alcohol peaks after drinking were clearly detected at 1.2 ppm for all durations of measurement. Good correlations between breath vapor or blood sample and MRS were found by sub-minute MRS measurement. The continuous measurement showed time-dependent changes in alcohol in the brain and various patterns that differed among subjects. Conclusions: The clinical 3T equipment enables direct evaluation of sub-minute changes in alcohol metabolism in the human brain.
    Magnetic Resonance in Medical Sciences 07/2013; · 0.75 Impact Factor
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    ABSTRACT: OBJECTIVES: The objective of this study was to evaluate the usefulness of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) and the relationships among the expressions of hypoxia-inducible factor-1α (HIF-1α), glucose transporter-1 (Glut-1) and vascular endothelial growth factor (VEGF), histological type, other clinical factors and FDG uptake in thymic epithelial tumours. METHODS: Thirty-three patients who underwent FDG-PET/CT before treatment were reviewed. All types of tumours were reclassified into three subgroups: low-risk thymomas (types A, AB and B1), high-risk thymomas (types B2 and B3) and thymic carcinomas. Tumour contour, pattern of FDG uptake, tumour size and maximum standardized uptake value (SUVmax) were obtained. Expressions of HIF-1α, Glut-1 and VEGF were analysed immunohistochemically, and these expressions were evaluated using grading scales. RESULTS: FDG uptake was visually recognized in all (100%) tumours. A homogeneous pattern of FDG uptake was increasingly observed in the order of low-risk thymomas to high-risk thymomas to thymic carcinomas (P = 0.016). SUVmax for thymic carcinomas was significantly higher than that for thymomas (P = 0.008). With the optimal cut-off value of SUVmax of 5.6, the sensitivity, specificity and accuracy for diagnosing thymic carcinoma were 0.75, 0.80 and 0.79, respectively. Regarding the mean scoring of HIF-1α, Glut-1 and VEGF, increasing trends were observed in the order of low-risk thymomas to high-risk thymomas to thymic carcinomas. Tumour size revealed a significant correlation with SUVmax (r = 0.60, P < 0.001), and the expression of HIF-1α showed a moderate association, but the expression of Glut-1 showed no correlation with SUVmax. Regarding correlations between the expression of the three markers, there were moderate associations between HIF-1α and Glut-1, and HIF-1α and VEGF, and a significant correlation between Glut-1 and VEGF (r = 0.60, P < 0.001). In type B1 thymoma, HIF-1α and Glut-1 were partly expressed in non-neoplastic immature lymphocytes. CONCLUSIONS: FDG-PET/CT should be performed in patients with tumours in the anterior mediastinum because the pattern of FDG uptake and SUVmax are useful in the differential diagnosis of thymic epithelial tumours. Furthermore, the expressions of HIF-1α, Glut-1 and VEGF might be associated with malignancy of thymic epithelial tumours. In contrast, FDG uptake might be dependent on tumour size rather than Glut-1 overexpression.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 05/2013; · 2.40 Impact Factor
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    ABSTRACT: Objective: To evaluate the usefulness of (201)Tl-SPECT in differentiating benign from malignant brain tumors. Methods and Materials: Eighty-eight patients (44 males and 44 females) with 58 high-grade (WHO grade III-IV) and 30 low-grade (WHO grade I-II) tumors were evaluated with (201)Tl-SPECT. (1) Visual assessment was performed by board-certificated radiologists using (201)Tl-SPECT. Tumors were classified in two groups (Tl-positive and Tl-negative) and scored using the five grade evaluation system. Receiver operating characteristic (ROC) analysis was performed in the Tl-positive group. (2) Semi-quantitative assessment involved measurement of early and delayed (201)Tl uptake, and the retention index (RI) was applied as follows: RI=delayed uptake ratio/early uptake ratio. Three combinations of RI using mean and maximum values of the region of interest were calculated. Results: (1) Seventy-four Tl-positive and 14 Tl-negative tumors. The area under the ROC curve (AUC) estimated by three radiologists exceeded a value of 0.7. The value was greater when estimated by the more experienced radiologist. (2) In all RIs, the difference of RI between high-grade tumors and low-grade tumors was statistically significant. Conclusion: A visual and semi-quantitative assessment using (201)Tl-SPECT was found to be useful for differentiating benign from malignant brain tumors. J. Med. Invest. 60: 121-126, February, 2013.
    The Journal of Medical Investigation 01/2013; 60(1-2):121-6.
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    ABSTRACT: Incidental (18)F-2-fluoro-2-deoxyglucose (FDG) uptake in blood vessel walls is sometimes demonstrated during routine oncologic imaging with positron emission tomography/computed tomography (PET/CT). FDG uptake in vessel walls can also be seen under some non-physiological conditions such as vasculitis and arteriosclerosis. Radiologists need to be aware of the diseases which can exhibit FDG uptake in the vessel wall for proper interpretation. J. Med. Invest. 60: 15-20, February, 2013.
    The Journal of Medical Investigation 01/2013; 60(1-2):15-20.
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    ABSTRACT: Objective: To evaluate the correlations between F-18 FDG uptake imaged with PET/CT and pathological findings in soft tissue lesions. Methods: Fifty-four soft tissue lesions in 47 patients were evaluated. The correlations between the degree of FDG uptake, pathological type and grade, and MRI signal intensity and/or enhancement pattern were evaluated. Tumor FDG uptake was quantified by the maximum standardized uptake value (SUVmax). Results: Thirty-one lesions were malignant and twenty-three lesions were benign. The difference between SUVmax in the malignant and benign groups was statistically significant (p<0.001). Malignant myxoid lesions and well differentiated liposarcoma showed low FDG uptake. Benign neurogenic lesions showed low FDG uptake while malignant neurogenic tumors showed high FDG uptake, and the difference between SUVmax in the benign and malignant lesions was statistically significant (p<0.001). In a neurofibromatosis type-1 patient who had multiple neurogenic tumors, FDG-PET/CT could distinguish malignant peripheral nerve sheath tumors from other benign lesions with similar MRI findings. Conclusions: FDG-PET/CT is useful for differentiating malignant from benign soft tissue lesions, but malignant soft tissue lesions may show various patterns on FDG-PET, and MRI may be helpful for a differential diagnosis. J. Med. Invest. 60: 184-190, August, 2013.
    The Journal of Medical Investigation 01/2013; 60(3-4):184-90.
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    ABSTRACT: The purpose of this retrospective study was to compare fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and ultrasonography (US) in the staging of patients with squamous cell carcinoma of the oral cavity. We compared preoperative evaluations regarding lymph nodes using PET/CT, US, and both methods. The cutoff for the maximum standardized uptake value (SUV(max)) in PET/CT was set at 2.7 by a receiver operating characteristic analysis that was based on the histopathological diagnosis. US was used to examine internal structural changes on B-mode and hilar vascularity on power Doppler. The performance of PET/CT and US in combination was better than that of each modality separately. However, there were histopathological changes that could not be detected on PET/CT or US. PET/CT could not detect nodes with necrotic or cystic changes. US could not detect lymph nodes that did not have abnormal structures. PET/CT and US are complementary tools to evaluate preoperative patients.
    Oral surgery, oral medicine, oral pathology and oral radiology. 10/2012; 114(4):516-25.
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    ABSTRACT: OBJECTIVES Postoperative follow-up and surveillance after curative resection for non-small-cell lung cancer (NSCLC) patients are generally performed. However, there is no consensus on the best programme at this time. The aim of this study was to evaluate the diagnostic capability of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in postoperative NSCLC patients without clinical and radiological evidence of recurrence, as a follow-up and surveillance programme. METHODS Between January 2005 and April 2010, a total of 101 NSCLC patients underwent potentially curative operations and follow-up FDG-PET/CT was performed in patients without clinical and radiological evidence of recurrence at least once a year in principle. A total of 233 FDG-PET/CT studies were entered and retrospectively reviewed. RESULTS Eighteen (18%) asymptomatic patients had recurrent diseases and 22 recurrent sites were confirmed. Of 22 recurrent sites, recurrence was diagnosed by histological examination in 9 (41%) sites and by imaging examination in 13 (59%) sites. FDG-PET/CT correctly diagnosed recurrence in 17 of the 18 (94%) patients and 21 of the 22 (95%) recurrent sites. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 94.4, 97.6, 89.5, 98.8 and 97.0%, respectively. On the other hand, in 3 patients, other diseases were detected and treated appropriately. Post-recurrence therapies were performed in all patients with recurrence, but 4 (22%) patients died of the original diseases. The median post-recurrence survival was 25.2 months, and the 1- and 2-year post-recurrence survival rates were 83.3 and 69.6%, respectively. CONCLUSIONS FDG-PET/CT is a useful tool that has high capability to detect recurrences in asymptomatic NSCLC patients after a potentially curative operation. However, a large-scale multi-institutional randomized control trial may be needed to ascertain the benefit of surveillance with FDG-PET/CT.
    Interactive Cardiovascular and Thoracic Surgery 08/2012; 15(5):859-64. · 1.11 Impact Factor
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    ABSTRACT: We evaluate whether integrated fluorodeoxyglucose-positron emission tomography and computed tomography (FDG-PET/CT) scan can diagnose the presence of lymph node metastasis more accurately than computed tomography (CT) scan alone. Forty-two patients with lung cancer preoperatively underwent integrated PET/CT scan using FDG and CT scan and underwent pulmonary resection and lymph node dissection. We judged cases as lymph node metastasis if the lymph node visually accumulated FDG at PET/CT scan and measured 1 cm or greater in the short axis at CT scan. We retrospectively analyzed whether our judgments in each modality were consistent with the pathological diagnosis. Two-hundred and seventeen stations of lymph node were dissected and 21 stations (9.7%) were histologically diagnosed as positive metastasis. Thirty-two stations of lymph node visually accumulated FDG at PET/CT scan and 17 stations measured 1 cm or greater in the short axis at CT scan. Concerning the diagnosis of lymph node metastasis, PET/CT scan showed significantly higher sensitivity than CT scan (81% vs. 48%, p=0.024). The false-positive rate was significantly high in PET-positive lymph nodes measuring less than 1 cm in diameter. There were 4 false-negative lymph nodes with both scans. All of these were less than 7 mm in diameter and had a low percentage of metastatic foci in the lymph node. Concerning the diagnosis of N staging, there was no significant difference between PET/CT scan and CT scan (83% vs. 69%, p=0.124). However, the identification of N2 disease at PET/CT scan was significantly more accurate than that at CT scan (100% vs. 38%, p=0.031). PET/CT is superior to CT scan in lymph node staging. However, because the false-positive rate is high in PET-positive lymph nodes measuring less than 1 cm in diameter, we think that clinical background should be considered and other modalities or histological examinations should be undertaken if necessary. J. Med. Invest. 57: 305-313, August, 2010.
    The Journal of Medical Investigation 08/2010; 57(3-4):305-13.
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    ABSTRACT: To evaluate (18)F-fluorodeoxyglucose (FDG) uptake and the pathological risk category of gastrointestinal stromal tumors (GISTs), and to investigate the possibility of determining the pathological risk category by positron emission tomography/computed tomography (PET/CT). Patients and We undertook 29 PET/CT studies in 20 patients with GISTs. Eleven of the 20 patients underwent PET/CT prior to therapy, with three of these also undergoing follow-up PET/CT after operation or imatinib therapy. All eleven lesions imaged before treatment were FDG-positive on PET/CT. Seven of these eleven primary lesions were categorized as high risk and the other four primary lesions were categorized as low or intermediate risk. There was a significant difference between the maximum standardized uptake value (SUVmax) of the primary lesions categorized as high risk (11.8±3.15) and that of the primary lesions categorized as low and intermediate risk (2.88±0.47) (p<0.001). Recurrent tumors were also shown as FDG-positive. Primary GISTs and recurrent tumors can be detected by PET/CT. Our study suggests that the degree of FDG uptake is a useful indicator of risk category. In addition, PET/CT is probably useful for follow-up examinations of GIST after operation or imatinib therapy. J. Med. Invest. 57: 270-274, August, 2010.
    The Journal of Medical Investigation 08/2010; 57(3-4):270-4.
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    ABSTRACT: The preoperative evaluation of venous thromboembolism (VTE) is important to avoid complications, because VTE is often induced by orthopedic surgery. We focused on radioisotope venography (RIV) using 99mTc-macroaggregated human serum albumin, examining orthopedic patients. We conducted 34 examinations in 33 patients who were referred for RIV and lung perfusion scintigraphy for the pre-orthopedic operative evaluation of VTE. Two board-certified (one nuclear medicine board-certified) radiologists interpreted the images based on the following: (1) flow defect of the lower extremities; (2) interruption of flow; (3) irregular or asymmetric filling of the deep vein (low flow); (4) presence of collateral vessels; and (5) abnormal RI retention on delayed-phase images. Scoring was based on a 5-point scale, and more than 2 points was considered VTE positive. Abnormal findings were noted in 27 of the 34 examinations performed in the 33 patients and normal findings in the other 7 examinations. According to the RI score, 21 patients were classified into the VTE-positive group and 12 into the VTE-negative group. Surgery was canceled because of advanced age and respiratory dysfunction in 2 of the 21 patients in the VTE-positive group. Of the 19 patients who underwent surgery, an IVH filter was placed before surgery in 2 and anticoagulant treatment with heparin and warfarin was initiated on the day of surgery in 12 to prevent postoperative VTE, and only one of the patients receiving anticoagulant treatment developed PTE after surgery. Surgery was canceled due to advanced age and at patient's request in 2 of 12 patients in the VTE-negative group. Anticoagulant treatment with heparin/ warfarin was performed to prevent postoperative VTE in only 3 patients: one with a past medical history of pulmonary infarction, one with atrial fibrillation, and one suspected of having antiphospholipid antibody syndrome. No patient in the VTE-negative group developed VTE after surgery. The preoperative identification of patients with VTE by RIV might be useful for perioperative management and the evaluation of preventive measures against postoperative VTE.
    Annals of Nuclear Medicine 02/2010; 24(2):107-13. · 1.41 Impact Factor
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    ABSTRACT: The aim of this study was to select a suitable substrate candidate for dynamic nuclear polarization (DNP) studies and demonstrate its utility for evaluating intracellular metabolism. Hyperpolarized substances included 1-(13)C-pyruvate (Pyr), 1-(13)C-glucose (Glc), and 1-(13)C-acetate. A DNP polarizer and a 600-MHz vertical small-bore scanner were used for (13)C-MR spectroscopic measurements. After polarization for 1 h, the dissolved solution was injected via a capillary line into the nuclear magnetic resonance tube in the scanner. The sequential spectra of the hyperpolarized (13)C-labeled substrates were acquired in durations of more than 120 s, and a thermal spectrum was obtained more than 1 h thereafter. FM3A cancer cells of mammary tumors were cultured for intracellular detection of the hyperpolarized (13)C-substances. The greatest sensitivity was found using Pyr with the longest T1 decay (51.5 s); and remarkably, the least sensitivity was observed using Glc with a signal decay of less than 2 s. An effective increase in sensitivity was shown using the other substances. The hyperpolarized intracellular study using (13)C-Pyr showed distinct elevation of lactate levels. The DNP technique is useful for evaluating intracellular metabolism. However, Glc is not suitable for use with the DNP technique.
    Japanese journal of radiology 02/2010; 28(2):173-9. · 0.73 Impact Factor
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    ABSTRACT: Advanced imaging techniques, including diffusion tensor imaging (DTI), perfusion-weighted imaging (PWI), and magnetic resonance spectroscopy (MRS) can provide more information than that regarding anatomy. These techniques have been commonly used in the clinical field and recently been shown useful in diagnosing brain tumors, especially in cases difficult to specify using conventional imaging. Differentiation requires more than attention to each advanced image. Diagnostic accuracy improves by combining information from MRS with that from other sequences, such as maps of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) generated from DTI and of cerebral blood volume (CBV) generated from PWI. We show clinical applications of advanced imaging techniques, combined MRS, for brain tumor.
    Magnetic Resonance in Medical Sciences 01/2010; 9(4):167-75. · 0.75 Impact Factor
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    ABSTRACT: We report the findings of Thallium-201 chloride ((201)TlCl) scintigraphy and consider how to use this technique to evaluate the character of soft tissue lesions. We enrolled 91 consecutive patients (45 males and 46 females, age range 8-91-years-old). Nineteen patients were malignant and 72 were benign. Patients were scanned 15 minutes (early phase) and 3 hours (delayed phase) after (201)TlCl injection. More intense uptake in the lesion compared to the normal side was considered as 'high', the same degree of uptake was considered 'iso', and decreased uptake was 'low'. The retention index (RI) was calculated in 9 patients in the malignant group and in 16 patients in the benign group. In malignant tumors, 15 of 19 patients showed high uptake in both the early and delayed phases. One malignant fibrous histiocytoma patient was high only in the delayed phase and 1 liposarcoma patient was high only in the early phase. Two liposarcoma patients showed an iso uptake in both phases. One of these patients was pathologically diagnosed as a myxoid type. In benign lesions, no lipoma showed increased uptake. All neurogenic tumors except for 2 demonstrated high uptake. All 3 ganglions of the lower extremities showed iso uptake. Most inflammatory diseases showed increased uptake. Clinically-considered benign patients consisted of tumorous lesions or inflammatory disease. Only 2 patients were considered 'low', and these were diagnosed as intramuscular hematoma and cyst. RI was variable in both malignant and benign lesions and no statistically significant difference was seen between malignant and benign lesions by t-test (p=0.72). A high (201)TlCl uptake lesion is more frequently seen in malignant tumors, but regardless of whether the tumor is benign or malignant, according to the histopathological variety, the (201)TlCl uptake pattern can not be the only indicator to differentiate malignant from benign tumors. We ultimately need to evaluate the nature of tumors by a combination of several imaging techniques.
    The Journal of Medical Investigation 08/2009; 56(3-4):136-41.
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    ABSTRACT: This study aimed to compare with bone scintigraphy showed round focal accumulation and Multidetector Row CT (MDCT) findings. We obtained 101 patients (mean age 69.2 years; 75 men, 26 women) and 186 diseases. They were examined both MDCT and bone scintigraphy within a month of each other. We classified into two groups (with metastasis and spondylosis) according to their MDCT findings. Bone scintigraphy was estimated on planar image, MDCT was evaluated in three directions with 1 x 1 x 1 mm thickness. We determined 20 metastases cases and 81 of spondylosis. We could not judge abnormal findings on MDCT in 4 patients (1 metastasis, 3 spondylosis); thus, detectability by MDCT was 93.5%. In the spondylosis group, the accumulation lesions were localized on the lower vertebral body in 76 patients (59%), with most showing as osteophytes. In the metastasis group, 11 patients showed more than 1 accumulations, 9 were osteoblastic changes and 10 were lytic. There was a tendency that patients who accumulated more than 1 vertebral bodies (64%) had osteoblastic and irregular distribution and those who accumulated just one body (78%) were lytic and their locations were focused on the lateral side. For evaluating bone scintigraphy, MDCT finding was helpful to increase the detectability in bone metastasis. Therefore, we should refer to MDCT finding positively in reading bone scintigraphy.
    Kaku igaku. The Japanese journal of nuclear medicine 04/2009; 46(1):13-20.
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    ABSTRACT: (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET/CT) was performed to evaluate a left femoral subcutaneous mass in a patient with von Recklinghausen's disease (vRd) that gradually enlarged, causing pain and numbness. The left femoral mass showed intense FDG uptake with the maximum standardized uptake value (SUVmax) of 9.0. Other subcutaneous masses considered benign and neurogenic in nature also showed FDG uptake (SUVmax around 3 or less), but the degree of FDG uptake differed considerably from the left femoral mass. This observation suggested that the degree of FDG uptake may be a useful indicator of malignant transformation. Incidentally, PET/CT also showed an asymptomatic large abdominal mass with intense FDG uptake (SUVmax 8.8). The abdominal mass was resected and confirmed as gastrointestinal stromal tumor (GIST) of the small intestine. Three months later, the left femoral mass was operated on and pathologically diagnosed as a malignant peripheral nerve sheath tumor (MPNST). Various malignant diseases are known to occur with high frequency in vRd. Therefore, vRd patients need to have periodical examinations including PET/CT. We present a rare case of a patient with vRd with a MPNST of the left femur and coincidental GIST of the small intestine. February, 2009.
    The Journal of Medical Investigation 03/2009; 56(1-2):76-9.
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    ABSTRACT: Imaging techniques such as CT, MRI and PET/CT have essential pre- and post-treatment roles in detecting tumors and evaluating the extension of malignant pleural mesothelioma (MPM). We sough to evaluate the advantages and limitations on FDG-PET/CT findings. We performed 13 FDG-PET/CT studies in 9 patients with MPM (8 males, 1 female, aged 51 to 84 years, 9 at the initial diagnosis, 4 follow up studies). We reviewed FDG-PET/CT findings of primary tumors, recurrent tumors, lymph nodes, metastasis. All primary and recurrent tumors were FDG positive. The uptake patterns at initial diagnosis were; diffuse+multi-nodular uptake pattern in 5, diffuse irregular thickened uptake pattern in 2, some focal thickened pattern in one, and a slight diffuse uptake pattern in one. Two of the 3 patients diagnosed as N0 by PET and operated on had negative lymph nodes confirmed pathologically. The other patient diagnosed as N0 by PET, who had one month of time lag between PET/CT examination and surgery, was confirmed as N2 by extrapleural pneumonectomy. In 3 patients, hilar or mediastinal lymph nodes were difficult to distinguish from irregular pleural thickening. One patient had a FDG positive lymph node in the ipsilateral supraclavicular region confirmed as metastasis (N3). One patient had a FDG positive lymph node in the para-aortic region. Lung metastasis was seen in one patient (M1). In another patient, two focal nodular uptakes in the colon were detected and confirmed as colon polyps (pathologically Group 3-4). At restaging, 3 of 4 patients showed diffuse+multi-nodular uptake and one patient showed multi-nodular uptake. The utility of FDG-PET/CT is limited for evaluation of primary tumor extension and nodal status. FDG-PET/CT is useful for detecting distant metastasis and for evaluating activity in supraclavicular or abdominal lymph nodes. It is also useful for identifying unsuspected diseases.
    The Journal of Medical Investigation 03/2009; 56(1-2):16-20.

Publication Stats

130 Citations
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17.90 Total Impact Points

Institutions

  • 2007–2013
    • The University of Tokushima
      • Department of Radiology
      Tokusima, Tokushima, Japan
  • 2008
    • University of Fukui
      • Biomedical Imaging Research Center
      Hukui, Fukui, Japan
  • 2004–2006
    • University of Iowa
      • Department of Radiology
      Iowa City, IA, United States
  • 2002–2005
    • Ehime Prefectural Central Hospital
      Matuyama, Ehime, Japan