Takashi Nihashi

Japanese Red Cross Kyoto Daiichi Hospital, Kioto, Kyōto, Japan

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Publications (40)98.64 Total impact

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    ABSTRACT: The purpose of this study was to assess the value of magnetic resonance imaging (MRI) and additional (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for tumor response to neoadjuvant chemotherapy (NAC) in patients with locally advanced rectal cancer (LARC). Data on 40 patients with LARC, who were treated with NAC and underwent MRI and FDG-PET/CT before and after NAC, were analyzed retrospectively. Surgery was performed at a median of 6 weeks after NAC and the images were compared with the histological findings. The tumor regression grade 3/4 was classified as a responder. Sixteen patients were pathological responders. Receiver operating characteristic (ROC) analysis revealed that MRI total volume after NAC (MRI-TV2) and ΔMRI-TV had the highest performance to assess responders (area under the ROC curve [AUC] 0.849 and AUC 0.853, respectively). The reduction rate of the maximum standardized uptake value (ΔSUVmax) was also an informative factor (AUC 0.719). There seems no added value of adding FDG-PET/CT to MRI-TV2 and ΔMRI-TV in assessment of NAC responders judging from changes in AUC (AUC of ΔSUVmax and MRI-TV2 was 0.844, and AUC of ΔSUVmax and ΔMRI-TV was 0.846). MRI-TV2 and ΔMRI-TV were the most accurate factors to assess pathological response to NAC. Although ΔSUVmax by itself was also informative, the addition of FDG-PET/CT to MRI did not improve performance. Patients with LARC who were treated by induction chemotherapy should receive an MRI examination before and after NAC to assess treatment response. A more than 70 % volume reduction shown by MRI volumetry may justify the omission of subsequent radiotherapy.
    Annals of Surgical Oncology 02/2014; · 4.12 Impact Factor
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    ABSTRACT: The purpose of this study was to examine the (11)C-methionine (MET) and (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) findings of central nervous system (CNS) germinoma and the diagnostic utility of these findings. We retrospectively evaluated the cases of 10 patients who were diagnosed with CNS germinoma according to their histopathological or clinical findings. All the patients underwent pretreatment MET and/or FDG-PET scans, and the resultant images were assessed qualitatively and quantitatively. In the qualitative assessments, we used 3- and 5-grade visual scoring systems for the MET- and FDG-PET images, respectively. In the quantitative assessments, the maximal standardized uptake value (SUVmax) and the ratio of the SUVmax of the tumor (T) divided by the mean SUV for the normal white or gray matter [T/N (WM), T/N (GM)], was calculated. The mean and SD values of SUVmax, T/N (WM), and T/N (GM) were 1.9 ± 1.4, 2.5 ± 1.3, and 1.7 ± 0.9 on MET-PET and 5.8 ± 2.2, 1.6 ± 0.5, and 0.8 ± 0.2 on FDG-PET, respectively. On MET-PET, only one lesion was not detected. On the other hand, on FDG-PET all of the lesions exhibited uptake values that were intermediate between those of the normal white matter and gray matter. In terms of its tumor-contouring ability, MET is a good tracer for diagnosing CNS germinomas; therefore, MET-PET is considered to be useful for planning biopsies or surgery. Although FDG-PET is capable of detecting CNS germinomas, it produced insufficient image contrast in the present study. Further studies are needed before FDG-PET can be used in clinical examinations of CNS germinoma.
    Annals of Nuclear Medicine 11/2013; · 1.41 Impact Factor
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    ABSTRACT: OBJECTIVE. The purpose of the study was to compare observer performance in the detection of cerebral infarction on a brain CT using medical-grade liquid crystal display (LCD) monitors calibrated with the gray-scale standard display function and with γ 2.2 and using an iPad with a simulated screen setting. MATERIALS AND METHODS. We amassed 97 sample sets, from 47 patients with proven cerebral infarction and 50 healthy control subjects. Nine radiologists independently assessed brain CT on a gray-scale standard display function LCD, a γ 2.2 LCD, and an iPad in random order over 4-week intervals. Receiver operating characteristic (ROC) analysis was performed by using the continuous scale, and the area under the ROC curve (Az) was calculated for each monitor. RESULTS. The Az values for gray-scale standard display function LCD, γ 2.2 LCD, and iPad were 0.875, 0.884, and 0.839, respectively. The difference among the three monitors was very small. There was no significant difference between gray-scale standard display function LCD and γ 2.2 LCD. However, the Az value was statistically significantly smaller for the iPad than the γ 2.2 LCD (p < 0.05). CONCLUSION. Observer performance for detecting cerebral infarction on the LCD with γ 2.2 calibration was found to be similar to the LCD with gray-scale standard display function calibration. Although observer performance using the iPad was poorer than that using the other LCDs, the difference was small. Therefore, the iPad could not substitute for other LCD monitors. However, owing to the promising potential advantages of tablet PCs, such as portability, further examination is needed into the clinical use of tablet PCs.
    American Journal of Roentgenology 06/2013; 200(6):1304-1309. · 2.90 Impact Factor
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    ABSTRACT: OBJECTIVE. Several studies have assessed PET to complement the anatomic information obtained from other imaging modalities in various clinical contexts for the management of glioma. We constructed an evidence map of clinical evidence on the use of PET in glioma and identified research gaps. MATERIALS AND METHODS. We searched PubMed and Scopus (from inception through June 30, 2011) to identify studies assessing the use of PET for glioma regardless of setting of care or indication. We extracted test objectives, study characteristics, and phases of diagnostic evidence and then assessed research diversity and temporal trends in the literature. We excluded studies assessing only technical feasibility and optimization of PET. RESULTS. A total of 129 studies were considered eligible; the number of articles published annually has greatly increased over time (p for trend < 0.001). Most studies (n = 118, 91%) assessed diagnostic or prognostic performance; fewer studies reported on the impact of PET on diagnostic thinking (n = 4, 3%), therapeutic decisions (n = 4, 3%), or patient-relevant clinical outcomes (n = 3; 2%). Fluorine-18 FDG (n = 73, 57%) or (11)C-methionine (n = 44, 34%) were the two most commonly evaluated PET tracers. Pretherapy assessment (n = 72, 56%) and monitoring of treatment response (n = 48, 37%) were the most common settings of test use assessed in the research studies. CONCLUSION. More primary studies, particularly studies of newer tracers focusing on biopsy or treatment planning, are needed to better characterize the role of PET in specific contexts.
    American Journal of Roentgenology 06/2013; 200(6):W654-W660. · 2.90 Impact Factor
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    ABSTRACT: OBJECTIVE: Differentiation between metastasis-free pancreatic cancer and mass-forming pancreatitis is important to avoid unnecessary operative procedures. This study was aimed at evaluating the efficacy of PET/CT with F-FDG (FDG PET/CT) for the differential diagnosis between them. PATIENTS AND METHODS: FDG-PET/CT was performed in 47 study patients with pancreatic masses and without any detectable metastases, 33 of which cases were finally diagnosed as pancreatic cancer and the other 14 as pancreatitis, and the corresponding imaging data were evaluated retrospectively. The maximal SUV (SUVmax) within the masses were determined at 1 hour and mostly at 2 hours after intravenous injection of FDG. RESULTS: SUVmax at 1 hour in pancreatic cancer was significantly higher than that in mass-forming pancreatitis, and the change in SUVmax from 1- to 2-hour time points was more consistent with pancreatic cancer than with mass-forming pancreatitis. However, there remained considerable overlapping between the SUVmax values of both diseases except either at the higher range for pancreatic cancer (>7.7 at 1 hour or >9.98 at 2 hours) or at the lower range for mass-forming pancreatitis (<3.37 at 1 hour or <3.53 at 2 hours). No obvious difference was found in the FDG uptake patterns of the mass areas between both diseases. CONCLUSIONS: Differentiation between metastasis-free pancreatic cancer and mass-forming pancreatitis is difficult by FDG-PET/CT due to considerable overlapping between the SUVmax values of the two diseases, although the differential diagnosis may be possible either at the higher range of SUVmax (> 7.7 at 1 hour or >9.98 at 2 hours) for pancreatic cancer or at the lower range of SUVmax (<3.37 at 1 hour or <3.53 at 2 hours) for mass-forming pancreatitis.
    Clinical nuclear medicine 03/2013; · 3.92 Impact Factor
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    ABSTRACT: The aim of our study was to examine the usefulness of PET with C-methionine (MET) and F-fluorodeoxyglucose (FDG) in the differentiation of glioblastoma multiforme (GBM) and intracranial diffuse large B-cell lymphoma (DLBCL). We evaluated 22 patients retrospectively with an enhancing brain tumor on MRI, including 15 GBM and 7 DLBCL, which was confirmed by histopathology. Dynamic PET scans with MET and FDG were performed for preoperative differential diagnosis. We assessed the images qualitatively and quantitatively. In quantitative assessment, the SUVmax was used on FDG PET and both late and early phases on MET PET. In addition, the ratio of SUVmax in the late and early phases on MET-PET was evaluated (ΔSUVmax). SUVmax on FDG PET of DLBCL was significantly higher than that of GBM. Setting an SUVmax of 12.0 as the cutoff for differentiating DLBCL from GBM, 1 GBM and 1 DLBCL were found to be false-positive and false-negative, respectively.SUVmax in the late and early phases of MET-PET was not significantly different between DLBCL and GBM; however, we also found significant differences in ΔSUVmax on MET-PET. Using ΔSUVmax 1.17 as the cutoff, we could differentiate DLBCL from GBM completely. In the present study, ΔSUVmax on MET-PET was slightly superior to SUVmax on FDG PET. Both SUVmax on FDG PET and ΔSUVmax on MET-PET were considered to be good diagnostic tests when encountering difficulties in this differential diagnosis.
    Clinical nuclear medicine 09/2012; 37(9):843-9. · 3.92 Impact Factor
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    ABSTRACT: Functional connectivity (FC) analysis with slow brain oscillation as measured by functional MRI has been shown to be useful in elucidating human brain's neural network activity. We examined if epileptogenic focus for the subjects with medically intractable lesion-related epilepsy could be detected by FC analysis. Cortical hub region map was created by calculating each cortical voxel's mean FC (correlation coefficient between the two voxels) to all other cortical voxels. Relatively high cortical hub regions were found around the lesions for all the subjects, which corresponded to the presumptive epileptogenic foci. These hubs had FC with the subcortical regions such as the basal ganglia and the thalamus. For 6 subjects with secondary generalized seizure, the hubs around the lesions had high FC with the ventral part of the posterior cingulate cortex (vPCC). The results suggest the usefulness of cortical hub map for the detection of epileptogenic focus and the networks involved in the propagation of seizure signals from the focus. Further, the FC between the presumptive focus and vPCC suggests that abnormal signal from the focus interferes the normal function of the default mode network even in inter-ictal state.
    Complex Medical Engineering (CME), 2012 ICME International Conference on; 01/2012
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    ABSTRACT: Three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) imaging after intratympanic gadolinium injection is useful for pathophysiologic and morphologic analysis of the inner ear. However, statistical analysis of differences in inner ear signal intensity among 3D-FLAIR and other sequences has not been reported. We evaluated the signal intensity of cochlear fluid on each of 3D-FLAIR, 3D-T(1)-weighted imaging (T(1)WI), and 3D-constructive interference in the steady state (CISS) to clarify the differences in contrast effect among these 3 sequences using intratympanic gadolinium injection. Twenty-one patients underwent 3D-FLAIR, 3D-T(1)WI, and 3D-CISS imaging at 3 tesla 24 hours after intratympanic injection of gadolinium. We determined regions of interest of the cochleae (C) and medulla oblongata (M) on each image, evaluated the signal intensity ratio between C and M (CM ratio), and determined the ratio of cochlear signal intensity of the injected side to that of the non-injected side (contrast value). The CM ratio of the injected side (3.00+/-1.31, range, 0.53 to 4.88, on 3D-FLAIR; 0.83+/-0.30, range, 0.36 to 1.58 on 3D-T(1)WI) was significantly higher than that of the non-injected side (0.52+/-0.14, range, 0.30 to 0.76 on 3D-FLAIR; 0.49+/-0.11, range, 0.30 to 0.71 on 3D-T(1)WI) on 3D-FLAIR and 3D-T(1)WI (P<0.001), although no significant difference was observed on 3D-CISS (10.03+/-2.19, range, 5.19 to 14.98, on the injected side; 9.52+/-1.63 range, 7.48 to 13.48, on the non-injected side) (P=0.11). The mean contrast value on 3D-FLAIR (5.93+/-2.57, range, 1.22 to 11.05) was significantly higher than that on 3D-T(1)WI (1.73+/-0.60, range, 0.98 to 3.09) (P<0.001). The 3D-FLAIR sequence is the most sensitive for observing alteration in inner ear fluid signal after intratympanic gadolinium injection. Our results warrant use of 3D-FLAIR as a sensitive imaging technique to clarify the pathological and morphological mechanisms of disorders of the inner ear.
    Magnetic Resonance in Medical Sciences 01/2010; 9(2):65-71. · 0.75 Impact Factor
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    ABSTRACT: We conducted a systematic review and meta-analysis to better define the prognostic ability of fluorine-18-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) following salvage chemotherapy for relapsed or refractory Hodgkin's lymphoma (HL) and aggressive non-Hodgkin's lymphoma. We searched PubMed (from inception to January 31, 2010), bibliographies, and review articles without language restriction. Two assessors independently assessed study characteristics, quality, and results. We performed a meta-analysis to determine prognostic accuracy. Twelve studies including 630 patients were eligible. The most commonly evaluated histologies were diffuse large B-cell lymphoma (n = 313) and HL (n = 187), which were typically treated with various salvage and high-dose chemotherapy regimens. Studies typically employed nonstandardized protocols and diagnostic criteria. The prognostic accuracy was heterogeneous across the included studies. (18)F-FDG PET had a summary sensitivity of 0.69 (95% confidence interval [CI], 0.56-0.81) and specificity of 0.81 (95% CI, 0.73-0.87). The summary estimates were stable in sensitivity analyses. In four studies that performed direct comparisons between PET and conventional restaging modalities, PET had a superior accuracy for predicting treatment outcomes. Subgroup and metaregression analyses did not identify any particular factor to explain the observed heterogeneity. (18)F-FDG PET performed after salvage therapy appears to be an appropriate test to predict treatment failure in patients with refractory or relapsed lymphoma who receive high-dose chemotherapy. Some evidence suggests PET is superior to conventional restaging for this purpose. Given the methodological limitations in the primary studies, prospective studies with standardized methodologies are needed to confirm and refine these promising results.
    The Oncologist 01/2010; 15(7):750-9. · 4.10 Impact Factor
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    ABSTRACT: PURPOSE I-123 IMP SPECT is a sensitive and accurate method for the detection of uveal malignant melanoma, whereas the efficacy of F18 -FDG PET for this purpose is low due to a high incidence of false negative results (Kato K, et al. J Nucl Med. 2006;47:404-409). The efficacy of F-18 Dopa PET/CT for detection of uveal malignant melanoma is unknown. The purpose of this study is to compare the efficacy of I-123 IMP SPECT, F-18 FDG PET/CT, and F-18 Dopa PET/CT for detection of uveal malignant melanoma. METHOD AND MATERIALS Seven patients with suspected uveal malignant melanoma were examined by I-123 IMP SPECT, F-18 FDG-PET/CT, and F-18 Dopa PET/CT. I-123 IMP SPECT was performed 24 hours after intravenous administration of I-123 IMP using a gamma camera (Symbia; Siemens, E.com Toshiba) with LEHR Fan-beam collimator. F-18 FDG-PET/CT and F-18 Dopa PET/CT was performed 60 minutes after intravenous administration of F-18 FDG using a PET/CT camera (Biograph, Siemens). RESULTS One case was positive in F-18 FDG PET/CT, whereas 4 cases were positive in I-123 IMP SPECT and F-18 Dopa PET/CT. In two cases which showed negative results with all these three examinations, there was no uveal melanoma lesion. One case is positive in I-123 IMP SPECT and in F-18 Dopa PET/CT, respectively, and these two cases were negative in the other two examinations; and in these two cases there were uveal malignant melanoma. In the cases which showed positive results with all these three examinations, the tumor diameter was longer than 1cm. On the other hand, the tumors with a diameter less than 1cm exhibited positive results in both I-123 IMP SPECT and F-18 Dopa PET/CT but negative results in F-18 FDG PET/CT. I-123 IMP SPECT seems to show higher tracer accumulation than F-18 Dopa PET/CT. CONCLUSION Uveal malignant melanoma with a diameter longer than 1cm exhibited positive results in all of I-123 IMP SPECT, F-18 FDG PET/CT, and F-18 Dopa PET/CT. The tumors with a diameter less than 1cm exhibited positive results in both I-123 IMP SPECT and F-18 Dopa PET/CT but negative results in F-18 FDG PET/CT. I-123 IMP SPECT seems to show higher accumulation than F-18 Dopa PET/CT in detecting uveal malignant melanoma with a diameter shorter than 1cm. CLINICAL RELEVANCE/APPLICATION F-18 FDG PET/CT is nearly equal to I-123 IMP SPECT in detecting uveal malignant melanoma and both are recommended for the diagnosis of such lesions.
    Radiological Society of North America 2009 Scientific Assembly and Annual Meeting; 12/2009
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    ABSTRACT: Changes in regional cerebral blood flow (rCBF) induced by unilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) were investigated in 7 consecutive patients with Parkinson's disease, 4 men and 3 women (mean age 62.3 +/- 8.1 years), who underwent rCBF measurement by N-isopropyl-p-(iodine-123)-iodoamphetamine single photon emission computed tomography at rest before and after unilateral STN DBS preoperatively in the on-drug condition, and postoperatively in the on-drug and on-stimulation condition. Statistical parametric mapping was used to identify significant changes in rCBF from the preoperative to the postoperative conditions. rCBF was increased in the bilateral cingulate cortices and bilateral cerebellar hemispheres. rCBF was decreased in the bilateral medial frontal cortices and left superior temporal cortex. Unilateral STN DBS produced rCBF changes in the bilateral cingulate cortices, cerebellar hemispheres, and medial frontal cortices. These findings indicate that unilateral STN DBS affects rCBF in both hemispheres.
    Neurologia medico-chirurgica 11/2009; 49(11):507-13. · 0.49 Impact Factor
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    ABSTRACT: We assessed the performance of 37 MBq I-123 as a diagnostic imaging agent in patients with differentiated thyroid cancer using comparisons with their corresponding high-dose post-treatment I-131 scans. We reviewed diagnostic I-123 whole-body scans and post-treatment I-131 scans of 69 patients who underwent I-131 therapy for differentiated thyroid carcinoma (47 papillary and 22 follicular). Diagnostic scans were performed 24 h following the oral administration of 37 MBq of I-123. I-131 doses were administered 3 days after the I-123 diagnostic scans using 2.22-7.4 GBq (median = 5.55 GBq). All images for diagnostic I-123 scans and the corresponding post-treatment I-131 scans were interpreted by consensus of at least 2 experienced radiologists. They evaluated the accumulations of radioiodine in the following 5 sites: thyroid bed, cervical and mediastinal lymph nodes, lung, bone and others. The concordance rates between I-123 scans and I-131 scans were calculated. A total of 108 sites were identified on the post-treatment I-131 scans. Seventy-seven sites (71%) were also identified on the I-123 diagnostic scans. The concordance rates between I-123 diagnostic scans and I-131 post-treatment scans were high for thyroid bed and bone metastases (89 and 86%, respectively), while they were low for lymph node and lung metastases on post-treatment scans (61 and 39%, respectively). Diagnostic scanning with relatively low dose I-123 is not always predictive of subsequent therapeutic I-131 uptake, especially for lymph node and lung metastases of differentiated thyroid cancer.
    Annals of Nuclear Medicine 09/2009; 23(9):777-82. · 1.41 Impact Factor
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    ABSTRACT: In the vestibular schwannoma patients, the pathophysiologic mechanism of inner ear involvement is still unclear. We investigated the status of the cochleae in patients with vestibular schwannoma by evaluating the signal intensity of cochlear fluid on pre- and post-contrast enhanced thin section three-dimensional fluid-attenuated inversion recovery (3D-FLAIR). Twenty-eight patients were retrospectively analyzed. Post-contrast images were obtained in 18 patients, and 20 patients had the records of their pure-tone audiometry. Regions of interest of both cochleae (C) and of the medulla oblongata (M) were determined on 3D-FLAIR images by referring to 3D heavily T2-weighted images on a workstation. The signal intensity ratio between C and M on the 3D-FLAIR images (CM ratio) was then evaluated. In addition, correlation between the CM ratio and the hearing level was also evaluated. The CM ratio of the affected side was significantly higher than that of the unaffected side (rho < 0.001). In the affected side, post-contrast signal elevation was observed (rho < 0.005). In 13 patients (26 cochleae) who underwent both gadolinium injection and the pure-tone audiometry, the post-contrast CM ratio correlated with hearing level (rho < 0.05). The results of the present study suggest that alteration of cochlear fluid composition and increased permeability of the blood-labyrinthine barrier exist in the affected side in patients with vestibular schwannoma. Furthermore, although weak, positive correlation between post-contrast cochlear signal intensity on 3D-FLAIR and hearing level warrants further study to clarify the relationship between 3D-FLAIR findings and prognosis of hearing preservation surgery.
    Neuroradiology 08/2009; 51(12):855-63. · 2.70 Impact Factor
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    ABSTRACT: To systematically review the prognostic accuracy of fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) for interim response assessment of patients with untreated advanced-stage Hodgkin's lymphoma (HL) or diffuse large B-cell lymphoma (DLBCL). MEDLINE, EMBASE, SCOPUS, and Biologic Abstracts were searched for relevant studies. Two assessors independently reviewed studies for inclusion and extracted data. Relevant unpublished data were requested from the investigators if unavailable from publications. A meta-analysis of the prognostic accuracy was performed. Thirteen studies involving 360 advanced-stage HL patients and 311 DLBCL patients met our inclusion criteria. Advanced-stage HL studies included few unfavorable-risk patients. DLBCL studies were heterogeneous. FDG-PET had an overall sensitivity of 0.81 (95% CI, 0.72 to 0.89) and a specificity of 0.97 (95% CI, 0.94 to 0.99) for advanced-stage HL, and a sensitivity of 0.78 (95% CI, 0.64 to 0.87) and a specificity of 0.87 (95% CI, 0.75 to 0.93) for DLBCL. Meta-regression and subgroup analyses did not identify factors that affect prognostic accuracy. For low- to intermediate-risk advanced-stage HL, FDG-PET performed after a few cycles of standard chemotherapy seems to be a reliable prognostic test to identify poor responders, warranting prospective studies to assess PET-based treatment strategies. For DLBCL, no reliable conclusions can be drawn due to heterogeneity. Interim PET remains an unproven test for routine clinical practice. Its use should be reserved for research settings where treatment regimens and imaging conditions are standardized.
    Journal of Clinical Oncology 04/2009; 27(11):1906-14. · 18.04 Impact Factor
  • NeuroImage 01/2009; 47. · 6.25 Impact Factor
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    ABSTRACT: A 45-year-old man presented with a headache. The medical history included a partial thyroidectomy, a colon polypectomy, and stomach tumors (all benign adenomas) 34, 2, and 1 year earlier, respectively. CT showed a space-occupying lesion in the left cerebellar hemisphere with calcification. The mass showed a striated pattern of hyperintensity on T2-weighted images. An FDG-PET scan was performed after the intravenous administration of 250 MBq (6.8 mCi) F-18 FDG. The images of the brain showed a hypermetabolic area in the left cerebellar hemisphere. The whole body images showed no abnormal accumulation other than physiologic uptake. A presumptive diagnosis of Lhermitte-Duclos disease (LDD) was made.
    Clinical Nuclear Medicine 02/2008; 33(1):52-4. · 2.96 Impact Factor
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    ABSTRACT: Although studies have shown that (18)F-FDG PET, when used to assess the response of malignant lymphoma after treatment, has a strong ability to predict relapse, its diagnostic accuracy in clinical practice remains unclear. The aim of this study was to systematically review the diagnostic accuracy of (18)F-FDG PET in detecting residual disease at the completion of first-line therapy of Hodgkin's disease (HD) and aggressive non-Hodgkin's lymphoma (NHL). We searched relevant articles from 1966 to July 2006 using MEDLINE, EMBASE, SCOPUS, Biological Abstracts, bibliographies, review articles, and textbooks without language restriction. One assessor (for non-English-language studies) or 2 assessors (for English-language studies) independently reviewed each article to abstract relevant study characteristics and results. Relevant individual patient data or subgroup data were provided by the investigators if they were unavailable from the publications. We estimated summary receiver operating characteristic curves and confidence regions for summary sensitivity and specificity. Nineteen studies consisting of 474 HD and 254 aggressive NHL patients were included. These studies had heterogeneity and suboptimal methodologic quality and reporting. Reported ranges for the sensitivity and specificity of (18)F-FDG PET in predicting disease relapse were 0.50-1.00 and 0.67-1.00, respectively, for HD and 0.33-0.77 and 0.82-1.00, respectively, for NHL. These estimates were similar when conventional imaging tests showed a residual mass. For HD studies, the summary receiver operating characteristic curves were similar irrespective of whether a residual mass was detected by conventional tests. Factors explaining the variability of diagnostic estimates were not identified. Although currently available evidence is still limited, (18)F-FDG PET seems to have good diagnostic accuracy for assessing residual HD at the completion of first-line treatment. Clinical data on this use of (18)F-FDG PET for aggressive NHL are more limited. Prospective studies with a more rigorous research design, conduct, and reporting would more reliably reveal the clinical diagnostic accuracy of this imaging modality.
    Journal of Nuclear Medicine 02/2008; 49(1):13-21. · 5.77 Impact Factor
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    ABSTRACT: Recent technical advances have enabled the visualization of neuromelanin in the substantia nigra pars compacta (SNc) and locus ceruleus (LC) by 3-tesla (T) magnetic resonance imaging in vivo. In the present study, we successfully detected neuromelanin in the SNc and LC of 6 healthy volunteers at 1.5T using a 3D gradient echo sequence with off-resonance magnetization transfer contrast.
    Magnetic Resonance in Medical Sciences 02/2008; 7(4):205-10. · 0.75 Impact Factor
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    ABSTRACT: Renal hemangiopericytoma (HPC) is a rare tumor. There are no unique radiological findings that can reliably aid in its preoperative diagnosis. A 60-year-old Japanese male was admitted for an abdominal mass. Ultrasound revealed a heterogeneous hyperechoic mass. Computed tomography (CT) showed a heterogeneous mass and tumor vascularity by a precontrast and dynamic study with maximum intensity projection (MIP) and volume-rendering technique (VRT). Radical nephrectomy was performed, and the histopathogic diagnosis revealed renal HPC.
    Acta Radiologica 11/2007; 48(8):934-7. · 1.33 Impact Factor
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    ABSTRACT: We assess the usefulness of F-18-fluoro-deoxyglucose (FDG) positron emission tomography (PET) in the evaluation of gastrointestinal metastases. Four cases (five lesions) in which metastases from three lung cancers and one malignant fibrous histiocytoma (MFH) of the femur were found in the gastrointestinal tract were reviewed (men/women 3 : 1, age 63-78 years, mean 72 years). The five lesions were duodenal, jejunal metastasis, and two stomach metastases from lung carcinoma, and rectal metastasis from MFH of the femur. FDG-PET was unable to detect small masses, but it was able to detect unforeseen lesions such as gastrointestinal metastases because FDG-PET is a whole-body scan in a single-operation examination. FDG-PET imaging provided valuable information for the diagnosis of gastrointestinal metastasis.
    Annals of Nuclear Medicine 09/2007; 21(6):361-5. · 1.41 Impact Factor

Publication Stats

382 Citations
98.64 Total Impact Points

Institutions

  • 2013
    • Japanese Red Cross Kyoto Daiichi Hospital
      Kioto, Kyōto, Japan
  • 2008–2013
    • Nagoya University
      • • Division of Radiology
      • • Graduate School of Medicine
      Nagoya, Aichi, Japan
    • National Center for Geriatrics and Gerontology
      • Department of Radiology
      Ōbu, Aichi-ken, Japan
  • 2010
    • Tufts Medical Center
      • Institute for Clinical Research and Health Policy Studies
      Boston, MA, United States
  • 2001–2003
    • The Graduate University for Advanced Studies
      • Department of Integrative Physiology
      Miura, Kanagawa-ken, Japan