Kimiteru Ito

Tokyo Metropolitan Hiroo Hospital, Edo, Tokyo, Japan

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Publications (81)191.8 Total impact

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    ABSTRACT: We used a new tracer, N-[4-[6-(isopropylamino) pyrimidin-4-yl]-1,3-thiazol-2-yl]-4-11C-methoxy-N-methylbenzamide (11C-ITMM), to compare radiation doses from positron emission tomography (PET)/computed tomography (CT) with previously published doses from PET alone. Twelve healthy volunteers [six males (mean age ± SD, 27.7 ± 6.7 years) and six females (31.8 ± 14.5 years)] in 12 examinations were recruited. Dose estimations from PET/CT were compared with those from PET alone. Regions of interest (ROIs) in PET/CT were delineated on the basis of low-dose CT (LD-CT) images acquired during PET/CT. Internal and external radiation doses were estimated using OLINDA/EXM 1.0 and CT-Expo software. The effective dose (ED) for 11C-ITMM calculated from PET/CT was estimated to be 4.7 ± 0.5 μSv/MBq for the male subjects and 4.1 ± 0.7 μSv/MBq for the female subjects. The mean ED for 11C-ITMM calculated from PET alone in a previous report was estimated to be 4.6 ± 0.3 μSv/MBq (males, n = 3). The ED values for 11C-ITMM calculated from PET/CT in the male subjects were almost identical to those from PET alone. The absorbed doses (ADs) of the gallbladder, stomach, red bone marrow, and spleen calculated from PET/CT were significantly different from those calculated from PET alone. The EDs of 11C-ITMM calculated from PET/CT were almost identical to those calculated from PET alone. The ADs in several organs calculated from PET/CT differed from those from PET alone. LD-CT images acquired during PET/CT may facilitate organ identification.
    No preview · Article · Jan 2016 · Australasian physical & engineering sciences in medicine / supported by the Australasian College of Physical Scientists in Medicine and the Australasian Association of Physical Sciences in Medicine
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    ABSTRACT: Purpose Progressive supranuclear palsy (PSP) is a neurodegenerative disorder characterized by supranuclear palsy, postural instability, and cognitive impairment. Recently, it has been reported that PSP comprises not only typical cases (i.e., Richardson's syndrome) but also various clinical subtypes with atypical symptoms such as levodopa-responsive parkinsonism, non-fluent aphasia and corticobasal syndrome. As well as clinical symptoms, the degree of midbrain atrophy, a well-known imaging hallmark, is not consistent in pathologically proven atypical PSP patients. This fact has important implications for the limitation of midbrain atrophy as a diagnostic biomarker of PSP pathology. The purpose of this study is to review magnetic resonance imaging (MRI) findings of pathologically proven typical and atypical PSP patients for educational presentations of the imaging spectrum of PSP. Methods We retrospectively reviewed conventional MRI mainly including T1-weighted, T2-weighted and fluid-attenuated inversion recovery images of 11 pathologically diagnosed PSP patients. Additionally, voxel based morphometry (VBM) analyses had been performed in six patients. Results As expected, typical PSP patients revealed typical atrophy of the midbrain and superior cerebellar peduncle. Contrary to typical patients, other findings including the atrophy of the frontal lobe, cerebral peduncle and globus pallidus were more conspicuous in atypical cases. Notably, the atrophy of the left inferior frontal gyrus in a patient with non-fluent aphasia (PSP-PNFA) and asymmetrical paracentral white matter atrophy in a patient with corticobasal syndrome (PSP-CBS) were characteristic findings. On the other hand, a patient with pure akinesia with gait freezing (PSP-PAGF) revealed only mild atrophy of the globus pallidus. In addition to these atrophic changes, some patients revealed dilatation of the third and fourth ventricle and T2 prolongation of the globus pallidus and brainstem tegmentum. VBM analyses were useful for the objective evaluation of the subtle atrophy of the frontal lobe white matter and basal ganglia which were difficult for visual assessment. Conclusions Radiologists should understand that in addition to the midbrain atrophy, PSP patients revealed the various imaging findings including abnormalities of the frontal lobe, globus pallidus and brainstem.
    No preview · Conference Paper · Sep 2015
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    ABSTRACT: Purpose: The aim of this multi-center study was to assess the diagnostic capability of visual assessment in L-methyl-11C-methionine positron emission tomography (MET-PET) for differentiating a recurrent brain tumor from radiation-induced necrosis after radiotherapy, and to compare it to the accuracy of quantitative analysis. Methods: A total of 73 brain lesions (glioma: 31, brain metastasis: 42) in 70 patients who underwent MET-PET were included in this study. Visual analysis was performed by comparison of MET uptake in the brain lesion with MET uptake in one of four regions (around the lesion, contralateral frontal lobe, contralateral area, and contralateral cerebellar cortex). The concordance rate and logistic regression analysis were used to evaluate the diagnostic ability of visual assessment. Receiver-operating characteristic curve analysis was used to compare visual assessment with quantitative assessment based on the lesion-to-normal (L/N) ratio of MET uptake. Results: Interobserver and intraobserver κ-values were highest at 0.657 and 0.714, respectively, when assessing MET uptake in the lesion compared to that in the contralateral cerebellar cortex. Logistic regression analysis showed that assessing MET uptake in the contralateral cerebellar cortex with brain metastasis was significantly related to the final result. The highest area under the receiver-operating characteristic curve (AUC) with visual assessment for brain metastasis was 0.85, showing no statistically significant difference with L/Nmax of the contralateral brain (AUC = 0.89) or with L/Nmean of the contralateral cerebellar cortex (AUC = 0.89), which were the areas that were the highest in the quantitative assessment. For evaluation of gliomas, no specific candidate was confirmed among the four areas used in visual assessment, and no significant difference was seen between visual assessment and quantitative assessment. Conclusion: The visual assessment showed no significant difference from quantitative assessment of MET-PET with a relevant cut-off value for the differentiation of recurrent brain tumors from radiation-induced necrosis.
    Preview · Article · Jul 2015 · PLoS ONE
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    ABSTRACT: The purpose of this study was to evaluate the clinical impact of addition of (11) C-PiB PET on routine clinical diagnosis of Alzheimer's disease (AD) dementia and mild cognitive impairment (MCI), and to assess diagnostic agreement between clinical criteria and research criteria of the NIA-AA. The diagnosis in 85 patients was made according to clinical criteria. Imaging examinations, including both MRI and SPECT/CT to identify neuronal injury (NI), and (11) C-PiB PET to identify amyloid were performed, and all subjects were re-categorized according to research criteria. Among 40 patients with probable AD dementia (ProAD), 37 were NI-positive, 29 were (11) C-PiB-positive, and 27 who were both NI- and (11) C-PiB-positive were categorized as having "ProAD dementia with a high level of evidence of the AD pathophysiological process". Among 20 patients with possible AD dementia (PosAD), 17 were NI-positive, and 6 who were both NI- and (11) C-PiB-positive were categorized as having "PosAD with evidence of the AD pathophysiological process". Among 25 patients with MCI, 18 were NI-positive, 13 were (11) C-PiB-positive, and 10 who were both NI- and (11) C-PiB-positive were categorized as having "MCI due to AD-high likelihood". Diagnostic concordance between clinical criteria and research criteria may not be high in this study. (11) C-PiB PET may be of value in making the diagnosis of dementia and MCI in cases with high diagnostic uncertainty. This article is protected by copyright. All rights reserved.
    No preview · Article · Jun 2015 · Psychiatry and Clinical Neurosciences
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    ABSTRACT: We evaluated factors associated with increased radiation exposure dose in nursing staff who assisted patients with (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)/computed tomography (CT) examinations. The Barthel Index and Mini-Mental State Examination (MMSE) score were obtained before PET/CT examinations in 193 patients (mean age ± SD, 77.7 ± 8.0 yr). Three nurses self-measured their radiation exposure dose while assisting patients during each PET examination. Disturbance factors during PET examinations (use of a stretcher or wheelchair, use of lines or tubes connected to the patient, use of diapers or urethral catheterization, patient age), (18)F-FDG injection dose, and previous PET/CT experience in the patients and outpatient or inpatient status were evaluated as factors possibly associated with increased radiation exposure. Principle component analysis, univariate analysis, and multivariate regression analysis were used for assessing associations between radiation exposure dose and factors. The mean radiation exposure dose of the nursing staff was 6.07 ± 5.71 µSv per examination. Statistically significant factors associated with increased radiation exposure (<8 or ≥8 µSv/case) in the univariate analysis were the Barthel Index (<75 or ≥75), MMSE score (<22 or ≥22) of the patients, numbers of lines or tubes to the patient, use of a stretcher or wheelchair, and (18)F-FDG injection dose. Multivariate logistic regression modeling showed that the Barthel Index (<75 or ≥75) and MMSE score (<22 or ≥22) of the patients were significant factors in the final model. Lower Barthel Indexes (lower ADL) and lower MMSE scores (lower cognitive function) were independent factors associated with increased radiation exposure dose in nursing staff assisting during (18)F-FDG PET/CT.
    No preview · Article · May 2015 · Journal of Occupational Health
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    ABSTRACT: PurposeWe examined the temperature of the intraventricular cerebrospinal fluid (Tv) in patients with Parkinson's disease (PD) and those with multiple system atrophy (MSA) in comparison with healthy subjects, and we examined normal changes in this temperature with aging.Methods Tv was estimated by magnetic resonance (MR) diffusion-weighted imaging (DWI) thermometry in 36 PD patients (19 males, 17 females), 34 MSA patients (17 males, 17 females), 64 age-matched controls (27 men, 37 women), and 114 all-age adult controls (47 men, 67 women; 28–89 years old). The volume of lateral ventricles was also estimated using FreeSurfer in all subjects. Tv and ventricular volume data were compared among the PD and MSA patients and age-matched controls. We also evaluated the relationship between Tv and age in the 114 all-age controls, controlling for ventricular volume. Men and women were analyzed separately.ResultsThe male PD and MSA patients had significantly higher Tv values compared to the male controls, with no significant difference in ventricular volume among them. There was no significant difference in Tv between the female patients and controls. In the all-age male controls, there was a significant negative correlation between Tv and age controlling for ventricular volume, and this was not observed in the women.ConclusionDWI thermometry is a useful and easy method for demonstrating an altered intracranial environment in male patients and healthy controls, but not in females. DWI thermometry can thus be used to help to explore the pathophysiology of Parkinsonian syndromes and to differentiate individuals affected by neurodegenerative disease with autonomic dysfunction from those without it.
    Full-text · Article · Apr 2015 · Brain and Behavior
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    ABSTRACT: The association between amygdala enlargement (AE) and temporal lobe epilepsy (TLE) has increasingly been reported. However, the pathology of AE remains poorly understood. The purpose of this study was to explore AE pathology using (11)C-methionine (Met) positron emission tomography (PET)/computed tomography (CT) in patients who have TLE with AE. Twenty-six TLE patients with AE and 18 TLE patients without AE underwent (11)C-Met PET/CT and magnetic resonance imaging (MRI). (11)C-Met uptake in amygdala was evaluated by both visual inspection and semi-quantitative measurement. MRI was assessed visually and semi-quantitatively for AE. Laterality index (LI) was obtained by comparing the amygdala volumes of ipsilateral and contralateral sides. The clinical course and histopathological findings of all patients were also analyzed. On (11)C-Met PET/CT images, visual examination detected increased uptake in the enlarged amygdala in 7 of 26 (27%) TLE patients with AE, and the results were confirmed by semi-quantitative analysis. Among six TLE patients with AE who underwent surgery, histopathology revealed neoplasms (low grade astrocytoma and gangliocytoma) in two patients and focal cortical dysplasia in one patient with increased (11)C-Met uptake, but non-neoplastic lesions (focal cortical dysplasia, vacuolar degeneration, and hamartoma) in all three patients with no increased (11)C-Met uptake. On MRI, volume of the affected amygdala was significantly larger compared to the contralateral amygdala. LI was significantly higher in the group with AE than in the group without AE. This study revealed that some TLE patients with AE showed increased (11)C-Met uptake in the enlarged amygdala. (11)C-Met PET/CT is potentially useful for the evaluation of AE pathology, and may provide beneficial information for appropriate decision-making. Copyright © 2015 Elsevier B.V. All rights reserved.
    No preview · Article · Mar 2015 · Epilepsy Research
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    ABSTRACT: The aims of this study were to evaluate the possibility of using (11)C-methionine ((11)C-MET) and (11)C-4'-thiothymidine ((11)C-4DST) whole-body PET/CT for the imaging of amino acid metabolism and DNA synthesis, respectively, when searching for bone marrow involvement in patients with multiple myeloma (MM) and to compare these findings with those for (18)F-FDG PET/CT and aspiration cytology. A total of 64 patients with MM, solitary plasmacytoma, monoclonal gammopathy of undetermined significance, or an unspecified diagnosis were prospectively enrolled. All the patients underwent three whole-body PET/CT examinations within a period of 1 week. First, the tracer accumulation was visually evaluated as positive, equivocal, or negative for 55 focal lytic lesions visualized using CT in 24 patients. Second, the percentages of marrow plasma cells as calculated using a bone marrow aspiration smear and tracer accumulation were evaluated in the posterior iliac crests of 36 patients. Among the 55 lytic lesions, the (11)C-MET and (11)C-4DST findings tended to reveal more positive findings than the (18)F-FDG findings. Based on the standard criteria for the diagnosis of active myeloma using the percentage of marrow plasma cells, significant differences were found between the (18)F-FDG and (11)C-MET findings and between the (18)F-FDG and (11)C-4DST findings, but no significant difference was observed between the (11)C-MET and (11)C-4DST findings. The addition of (11)C-MET and (11)C-4DST to (18)F-FDG when performing PET/CT enabled clearer evaluations of equivocal lesions. Based on cytological diagnostic criteria, (11)C-MET and (11)C-4DST were more sensitive than (18)F-FDG for the detection of active lesions. (11)C-MET and (11)C-4DST were more useful than (18)F-FDG for the detection of active lesions, especially during the early stage of disease.
    Preview · Article · Nov 2014 · Annals of Nuclear Medicine
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    ABSTRACT: Although a correct diagnosis is important for appropriate management, accurately differentiating between multiple system atrophy with predominant parkinsonism (MSA-P) and Parkinson's disease (PD) is often difficult because of similarities in the early-stage symptoms. The aim of this study was to evaluate the diagnostic value of cerebral perfusion single photon emission computed tomography (SPECT) and voxel-based analysis for diagnosing MSA-P patients. Thirty-eight subjects (9 with early-stage MSA-P, 11 with PD, and 18 controls) were included in this study. Z-scores suggestive of hypoperfusion were calculated between patients and controls using statistical parametric mapping (SPM) 8 and easy Z-score imaging system (eZIS) programs. A voxel-based stereotactic extraction estimation (vbSEE) program was performed to determine the target volumes of interest (VOIs) in the putamen, pons, and cerebellum, and quantify Z-scores as "extent" (the rate of voxels with a Z-score >2.0 in these VOIs) and "severity" (average Z-scores in these VOIs). These parameters were used as the determinant in receiver operating characteristic (ROC) analyses. The extent and severity of the cerebellar VOIs were higher in MSA-P patients than in PD patients. In ROC analyses, the extent and severity of the cerebellar VOI exhibited the highest areas under the curves of 0.86 and 0.84, and accuracies of 90 and 90 %, respectively. The diagnostic value of significant cerebellar hypoperfusion was the highest for differentiating MSA-P from PD. This voxel-based analysis of cerebral perfusion SPECT using the SPM8, eZIS, and vbSEE programs is useful for clinically diagnosing MSA-P.
    No preview · Article · Nov 2014 · Annals of Nuclear Medicine
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    ABSTRACT: Objective: We prospectively compared the diagnostic value of PET/computed tomography (CT) findings using the tracers 4'-[methyl-11C]-thiothymidine (11C-4DST) and 2-deoxy-2-18F-fluoro-D-glucose (18F-FDG) in patients with head and neck squamous cell carcinoma (HNSCC). Patients and methods: Thirty-eight patients with advanced HNSCC underwent 11C-4DST PET/CT and 18F-FDG PET/CT before treatment. Maximum standardized uptake values (SUVmax) were measured for both PET/CT studies; in addition, total lesion glycolysis (TLG) of 18F-FDG PET/CT and total lesion proliferation (TLP) of 11C-4DST PET/CT were measured. Absolute TLG and TLP values as well as values with various SUV thresholds were measured. All patients were followed up for 13.5±7.5 months (mean±SD) to monitor recurrence. Results: A statistically significant correlation was observed between the primary tumor SUVmax for 11C-4DST PET/CT and 18F-FDG PET/CT (r=0.46, P<0.01). TLP values with SUV thresholds strongly correlated with TLG values relative to the same thresholds (r=0.60-0.92, P<0.001). Nine of the 38 patients with post-treatment recurrence were identified. Receiver operating characteristic curves for TLG3.0 and TLP2.5 showed the highest prognostic ability for recurrence; the sensitivity and specificity of TLG3.0 were 89 and 72%, respectively, and the sensitivity and specificity of TLP2.5 were 89 and 55%, respectively. Conclusion: In patients with advanced HNSCC, the TLP of 11C-4DST PET/CT strongly correlated with the TLG of 18F-FDG PET/CT. Although there were no large differences between these values, the receiver operating characteristic curves of the absolute TLG had slightly better prognostic ability for recurrence.
    No preview · Article · Nov 2014 · Nuclear Medicine Communications
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    ABSTRACT: The purpose of this study was to clarify the concordance of diagnostic abilities and interobserver agreement between (18) F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and brain perfusion single photon-emission computed tomography (SPECT) in patients with Alzheimer's disease (AD) who were diagnosed according to the research criteria of the National Institute of Aging-Alzheimer's Association Workshop. Fifty-five patients with "AD and mild cognitive impairment (MCI)" (n = 40) and "non-AD" (n = 15) were evaluated with (18) F-FDG PET and (99m) Tc-ethyl cysteinate dimer (ECD) SPECT during an 8-week period. Three radiologists independently graded the regional uptake in the frontal, temporal, parietal, and occipital lobes as well as the precuneus/posterior cingulate cortex in both images. Kappa values were used to determine the interobserver reliability regarding regional uptake. The regions with better interobserver reliability between (18) F-FDG PET and (99m) Tc-ECD SPECT were the frontal, parietal, and temporal lobes. The (99m) Tc-ECD SPECT agreement in the occipital lobes was not significant. The frontal, temporal, and parietal lobes showed good correlations between (18) F-FDG PET and (99m) Tc-ECD SPECT in the degree of uptake, but the occipital lobe and precuneus/posterior cingulate cortex did not show good correlations. The diagnostic accuracy rates of "AD and MCI" ranged from 60% to 70% in both of the techniques. The degree of uptake on (18) F-FDG PET and (99m) Tc-ECD SPECT showed significant correlations in the frontal, temporal, and parietal lobes. The diagnostic abilities of (18) F-FDG PET and (99m) Tc-ECD SPECT for "AD and MCI," when diagnosed according to the National Institute of Aging-Alzheimer's Association Workshop criteria, were nearly identical. Copyright © 2014 John Wiley & Sons, Ltd.
    No preview · Article · Oct 2014 · International Journal of Geriatric Psychiatry
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    ABSTRACT: Objective: The purpose of this study was to evaluate the cardiac sarcoidosis (CS) activity according to the classified visual uptake pattern using (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and assess the uptake pattern based on the free fatty acid (FFA) levels. Methods: Nineteen CS subjects who underwent (18)F-FDG PET/CT examinations with heparin loading (HL) were recruited to evaluate their CS activity. The (18)F-FDG uptake in the heart was classified into five categories ("none," "diffuse" and "diffuse at base," regarded as stable CS, and "focal" and "focal on diffuse," regarded as de novo or worsening CS). The subject data were compared with the (18)F-FDG PET/CT findings in 13 healthy volunteers. The FFA serum levels were assessed in 10 patients with CS and all volunteers. Results: The sensitivity and specificity of (18)F-FDG PET/CT with HL were 75% (6/8) and 73% (8/11), respectively. The major pattern of cardiac (18)F-FDG uptake was "diffuse at base." Ten of the 32 subjects, including the control group, exhibited this pattern. The FFA serum levels before heparin administration were statistically significantly different between the patients with the "none" pattern and those with the "diffuse" and "diffuse at base" patterns. There were no significant correlations between the FFA serum levels after heparin administration and the (18)F-FDG uptake patterns. Conclusion: "Diffuse at base" is the major (18)F-FDG uptake pattern associated with inadequate physiologic (18)F-FDG suppression. This pattern should be carefully interpreted when examining the (18)F-FDG PET/CT images of CS patients. Additionally, increased FFAs levels associated with HL may not completely suppress the physiologic myocardial FDG uptake.
    No preview · Article · Sep 2014 · Internal Medicine
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    ABSTRACT: PURPOSEThe purpose of the present retrospective study was to evaluate the sensitivity of susceptibility-weighted imaging (SWI) compared to conventional spin-echo T2-weighted and T2*-weighted images in detecting iron deposition in the motor cortex of amyotrophic lateral sclerosis (ALS) patients in comparison with age-matched normal controls. We also investigated the etiology of the low signal referring to the pathology of one autopsy case.METHODS This retrospective magnetic resonance (MR) study included 23 ALS patients and 28 age-matched normal controls. The signal intensity of the motor cortex was scored by SWI, conventional T2-weighted images and T2*-weighted images. A postmortem study of one patient was also performed.RESULTSOn SWI, there was a significant difference between the precentral cortical signal intensity scores in the ALS patients and the controls (P < .0001). The total scores of signal intensities of the precentral cortex were positively correlated with age in the normal controls (r = .494), but no correlation was observed in the ALS patients. The postmortem study showed intensely stained microglias and macrophages after antiferritin antibody staining in the precentral cortices.CONCLUSIONS Decreased signal intensity of the motor cortex on SWI may serve a useful role in ALS diagnoses, particularly in young patients. MR images were also helpful for speculating on the etiology of ALS.
    No preview · Article · Jun 2014 · Journal of neuroimaging: official journal of the American Society of Neuroimaging
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    ABSTRACT: Arterial spin labeling (ASL) magnetic resonance imaging (MRI) is a novel noninvasive technique that can measure regional cerebral blood flow (rCBF). To our knowledge, few studies have examined rCBF in patients with schizophrenia by ASL-MRI. Here we used pseudo-continuous ASL (pCASL) to examine the structural and functional imaging data in schizophrenic patients, taking the regional cerebral gray matter volume into account. The subjects were 36 patients with schizophrenia and 42 healthy volunteers who underwent 3-tesla MRI, diffusion tensor imaging (DTI), and pCASL. We evaluated the gray matter volume imaging, DTI, and pCASL imaging data in a voxel-by-voxel statistical analysis. The schizophrenia patients showed reduced rCBF in the left prefrontal and bilateral occipital cortices compared to the healthy volunteers. There was a significant reduction of gray matter volume in the left inferior frontal cortex in the schizophrenia patients. With respect to the fractional anisotropy (FA) values in the DTI, there were significant FA reductions in the left superior temporal, left external capsule, and left inferior prefrontal regions in the patients compared to the controls. Conclusion Our pCASL study with partial volume effect correction together with volumetry and DTI data demonstrated hypoactivity in the left prefrontal area beyond structural abnormalities in schizophrenia patients. There were also hypofunction areas in bilateral occipital cortices, although structural abnormalities were not apparent.
    No preview · Article · Apr 2014 · Schizophrenia Research
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    ABSTRACT: 4[prime]-[Methyl-11C]-thiothymidine (4DST) is a novel positron emission tomography (PET) tracer to assess proliferation of malignancy. The diagnostic abilities of 4DST and 2-deoxy-2-18 F-fluoro-d-glucose (FDG) for detecting regional lymph node (LN) metastases of non-small cell lung cancer (NSCLC) were prospectively compared. In addition, the relationship between the PET result and the patient's prognosis was evaluated. A total of 31 patients with NSCLC underwent 4DST PET/computed tomography (CT) and FDG PET/CT. The PET/CT images were evaluated qualitatively and quantitatively for focal uptake of each PET tracer, according to the staging system of the American Joint Committee on Cancer. Surgical and histological results provided the reference standards. Patients were followed for up to two years to assess disease-free survival. On a per-lesion basis, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for LN staging were 82%, 72%, 32%, 96%, and 73%, respectively, for 4DST, and 29%, 86%, 25%, 88%, and 78%, respectively, for FDG. The sensitivity of 4DST was significantly higher than that of FDG (P < 0.001). The disease-free survival rate with positive 4DST uptake in nodal lesions was 0.35, which was considerably lower than the rate of 0.83 with negative findings (P = 0.04). Among the factors tested, nodal staging by 4DST was the most influential prognostic factor (P = 0.05) in predicting the presence of a previously existing spread lesion or of a recurrence over the course of 2 years. 4DST PET/CT is sensitive for detecting mediastinal lymph node metastasis in NSCLC, but its low specificity is a limitation. However, it may be helpful in predicting the prognosis of NSCLC.
    Full-text · Article · Mar 2014 · EJNMMI Research
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    ABSTRACT: BACKGROUND AND PURPOSEAmygdala enlargement (AE) has been reported as an epileptogenic focus in subtypes of temporal lobe epilepsy (TLE). The purpose of this study was to investigate the clinical, morphological, and pathological characteristics of AE. METHODS We retrospectively reviewed the clinical data and imaging findings of 23 TLE patients with ipsilateral AE. We performed morphological MR analyses using FreeSurfer and voxel-based morphometry (VBM) in 14 of the 23 patients and in 20 controls whose images were obtained by a 3.0-Tesla MRI. A pathological study was also performed in 2 patients who underwent operations. RESULTSAll patients became seizure free or shSowed dramatic improvement by medical therapy except for two. They received operations and their pathology revealed that both patients had cortical dysplasia in from the amygdala to the ipsilateral temporal pole. The FreeSurfer analysis showed a significant difference in the amygdala volumes between the affected and nonaffected sides. VBM revealed significant increases of gray matter volumes of the temporal pole on the side of AE in seven of the 14 patients with AE (50%). CONCLUSIONS Cortical dysplasia may be one of the pathological diagnoses in AE, and in some patients it may extend to the temporal pole.
    Full-text · Article · Feb 2014 · Journal of neuroimaging: official journal of the American Society of Neuroimaging
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    ABSTRACT: To clarify the prognostic value of post-treatment (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in patients with advanced head and neck squamous cell carcinoma (HNSCC) after combined intra-arterial chemotherapy and radiotherapy (IACR). Thirty-six patients with HNSCC who underwent IACR were recruited. The period from the end of IACR to the last post-treatment (18)F-FDG PET/CT examination was 8-12 weeks. Both patient-based and lesion-based analyses were used to evaluate the PET/CT images. For lesion-based analysis, 36 regions (12 lesions of recurrences and 24 scars at primary sites) were selected. The Kaplan-Meier method was used to assess the overall survival (OS) stratified by (18)F-FDG uptake or visual interpretation results. Twelve patients with recurrence were identified by six months after IACR. The sensitivity and specificity in the patient-based analysis were 67% (8/12) and 88% (21/24), respectively. The mean OS was estimated to be 12.1 months (95% CI, 6.3-18.0 months) for the higher maximum standardized uptake value (SUVmax) group (n=7) and 44.6 months (95% CI, 39.9-49.3 months) for the lower SUVmax group (n=29). OS in the higher SUVmax group (cut-off point, 6.1) or positive visual interpretation group was significantly shorter than that in the lower SUVmax or negative visual interpretation group (P<0.001 and P<0.05, respectively). The SUVmax and visual interpretation of HNSCC on post-IACR (18)F-FDG PET/CT can provide prognostic survival estimates.
    No preview · Article · Feb 2014 · Chinese Journal of Cancer Research
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    ABSTRACT: F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is a promising modality for detecting active lesions of cardiac sarcoidosis (CS). However, determining whether 18F-FDG uptake in the myocardium is physiological is challenging due to metabolic shift in myocardial cells. Although methods for inhibiting physiological myocardial 18F-FDG uptake have been proposed, no standard methods exist. This study therefore aimed to compare the effect of an 18-h fast (long fasting (LF)) with heparin loading plus a 12-h fast (HEP) before 18F-FDG PET scan. We analyzed the effects of LF and HEP on the inhibition of physiological myocardial 18F-FDG uptake in healthy subjects (18 in HEP and 19 in LF) and in patients with known or suspected CS (96 in HEP and 69 in LF). In CS, the lower uptake of 18F-FDG in the myocardium was evaluated. A visual four-point scale was used to assess myocardial 18F-FDG uptake in comparison with hepatic uptake (1 lower, 2 similar, 3 somewhat higher, 4 noticeably higher). Myocardial 18F-FDG uptake was 1.68 +/- 1.06 in LF and 3.17 +/- 1.16 in HEP in healthy subjects (p < 0.0001), whereas it was 1.48 +/- 0.99 in LF and 2.48 +/- 1.33 in HEP in CS patients (p < 0.0001). Logistic regression and regression trees revealed the LF was the most effective in inhibiting myocardial 18F-FDG uptake. In addition, serum free fatty acid levels on intravenous 18F-FDG injection were a possible biomarker. LF is effective in inhibiting myocardial 18F-FDG uptake, and consequently, it could be useful for evaluating active lesions of CS in 18F-FDG PET images.
    Full-text · Article · Jan 2014 · EJNMMI Research
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    ABSTRACT: In multiple system atrophy with predominant parkinsonism (MSA-P), several voxel-based morphometry (VBM) studies have revealed gray matter loss; however, the white matter volume changes have been rarely reported. We investigated the volume changes of white matter as well as gray matter by VBM. A retrospective MRI study was performed in 20 patients with MSA-P and 30 age-matched healthy controls. We applied VBM with statistical parametric mapping (SPM8) plus diffeomorphic anatomical registration through exponentiated Lie algebra (DARTEL) to explore the regional atrophy of gray and white matter in all of the MSA-P patients, 14 patients with left-side dominant and 6 patients with right-side dominant onset as compared to controls. In all of the MSA-P patients, VBM revealed a significant volume reduction of gray matter in the bilateral putamina, cerebellums and dorsal midbrain. White matter loss was located in bilateral globus pallidi, external capsules extending to the midbrain, right subcortical to precentral area through internal capsule, the pons, bilateral middle cerebellar peduncles and left cerebellum. In left-side dominant MSA-P patients, the gray and white matter volume loss was detected predominantly on the right side and vice versa in right-side dominant MSA-P patients. A correlation with disease duration and severity was not detected. VBM using SPM8 plus DARTEL detected significant volume loss not only in the gray but also in the white matter of the area affected by MSA-P.
    Full-text · Article · Dec 2013 · Clinical neuroimaging
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    ABSTRACT: In infants with hemimegalencephaly, asymmetrical white-matter intensities suggestive of advanced myelination are observed as well as aberrant midsagittal fibers (AMFs) specific to hemimegalencephaly. Also noted are otherwise unreported abnormally enlarged periventricular fibers (APVFs) running anteroposteriorly along the caudate nucleus. This study investigated the degree of myelination and presence of aberrant fibers in hemimegalencephaly through a retrospective review of MRI scans in relation to histopathological findings. MRI scans of 24 infants with hemimegalencephaly (13 boys and 11 girls, 1-9 months old) were evaluated, focusing on the presence and signal intensities of AMFs and APVFs. White-matter signal intensities on T1- and T2-weighted imaging of the cerebral hemisphere were also evaluated and compared with the timetable for normal myelination. Surgical specimens were pathologically examined with Klüver-Barrera staining in four patients. AMFs and APVFs were observed in 18 and nine patients, respectively, while 22 patients had accelerated myelination of the megalencephalic hemisphere that tended to extend along fiber pathways including AMFs and APVFs. In six cases, accelerated myelination even extended into the contralateral hemisphere via the corpus callosum or AMFs. Histopathological analysis identified hypermyelination with disarrayed myelinated fibers corresponding to MRI findings. Accelerated myelination is frequently observed in patients with hemimegalencephaly and tends to extend along fiber pathways, including aberrant or abnormal fibers, as seen in 75% of hemimegalencephaly patients. Accelerated myelination may reflect propagation pathways of abnormal brain activity in such patients.
    No preview · Article · Sep 2013 · Journal of Neuroradiology

Publication Stats

555 Citations
191.80 Total Impact Points

Institutions

  • 2015
    • Tokyo Metropolitan Hiroo Hospital
      Edo, Tokyo, Japan
    • Tokyo Metropolitan Institute
      Edo, Tokyo, Japan
  • 2014-2015
    • Tokyo Metropolitan Geriatric Medical Center
      Edo, Tōkyō, Japan
  • 2011-2015
    • National Center of Neurology and Psychiatry
      • Department of Radiology
      Кодаиры, Tōkyō, Japan
  • 2013-2014
    • Tokyo Metropolitan Institute of Gerontology
      Edo, Tōkyō, Japan
  • 2011-2014
    • National Center for Global Health and Medicine in Japan
      Edo, Tokyo, Japan
  • 2009-2011
    • Saitama Medical University
      • Department of Nuclear Medicine
      Саитама, Saitama, Japan
  • 2010
    • Jichi Medical University
      Totigi, Tochigi, Japan