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Featured researches published by Sunao Mizumura.


American Journal of Neuroradiology | 2012

Automatic Voxel-Based Morphometry of Structural MRI by SPM8 plus Diffeomorphic Anatomic Registration Through Exponentiated Lie Algebra Improves the Diagnosis of Probable Alzheimer Disease

Hiroshi Matsuda; Sunao Mizumura; Kiyotaka Nemoto; Fumio Yamashita; Etsuko Imabayashi; Noriko Sato; Takashi Asada

BACKGROUND AND PURPOSE: The necessity for structural MRI is greater than ever to both diagnose AD in its early stage and objectively evaluate its progression. We propose a new VBM-based software program for automatic detection of early specific atrophy in AD. MATERIALS AND METHODS: A target VOI was determined by group comparison of 30 patients with very mild AD and 40 age-matched healthy controls by using SPM. Then this target VOI was incorporated into a newly developed automated software program independently running on a Windows PC for VBM by using SPM8 plus DARTEL. ROC analysis was performed for discrimination of 116 other patients with AD with very mild stage (n = 45), mild stage (n = 30) and moderate-to-advanced stages (n = 41) from 40 other age-matched healthy controls by using a z score map in the target VOI. RESULTS: Medial temporal structures involving the entire region of the entorhinal cortex, hippocampus, and amygdala showed significant atrophy in the patients with very mild AD and were determined as a target VOI. When we used the severity score of atrophy in this target VOI, 91.6%, 95.8%, and 98.2% accuracies were obtained in the very mild AD, mild AD, and moderate-to-severe AD groups, respectively. In the very mild AD group, a high specificity of 97.5% with a sensitivity of 86.4% was obtained, and age at onset of AD did not influence this accuracy. CONCLUSIONS: This software program with application of SPM8 plus DARTEL to VBM provides a high performance for AD diagnosis by using MRI.


Annals of Nuclear Medicine | 2009

Contribution of subtraction ictal SPECT coregistered to MRI to epilepsy surgery: a multicenter study

Hiroshi Matsuda; Kazumi Matsuda; Fumihiro Nakamura; Shigeki Kameyama; Hiroshi Masuda; Taisuke Otsuki; Hideyuki Nakama; Hiroshi Shamoto; Nobukazu Nakazato; Masahiro Mizobuchi; Joji Nakagawara; Takato Morioka; Yasuo Kuwabara; Hideo Aiba; Masayuki Yano; Yeong-Jin Kim; Hiroyuki Nakase; Ichiei Kuji; Yoko Hirata; Sunao Mizumura; Etsuko Imabayashi; Noriko Sato

ObjectiveA multicenter prospective study was performed to assess the additional value of a subtraction ictal SPECT coregistered to MRI (SISCOM) technique to traditional side-by-side comparison of ictal- and interictal SPECT images in epilepsy surgery.MethodsOne hundred and twenty-three patients with temporal and extratemporal lobe epilepsy who had undergone epilepsy surgery after evaluation of scalp ictal and interictal electroencephalogram (EEG), MRI, and ictal and interictal SPECT scans were followed up in terms of postsurgical outcome for a period of at least 1xa0year. Three reviewers localized the epileptogenic focus using ictal and interictal SPECT images first by side-by-side comparison and subsequently by SISCOM. Concordance of the localization of the epileptogenic focus by SPECT diagnosis with the surgical site and inter-observer agreement between reviewers was compared between side-by-side comparison and SISCOM. Logistic regression analysis was performed in predicting the surgical outcome with the dependent variable being the achievement of a good postsurgical outcome and the independent variables using the SISCOM, side-by-side comparison of ictal and interictal SPECT images, MRI, and scalp ictal EEG.ResultsThe SISCOM presented better concordance in extratemporal lobe epilepsy and less concordance in temporal lobe epilepsy than side-by-side comparison. Inter-observer concordance was higher in SISCOM than in side-by-side comparison. Much higher concordance of the epileptogenic focus by SPECT diagnosis with the surgical site was obtained in patients with good surgical outcome than in those with poor surgical outcome. These differences in concordance between good and poor surgical outcomes were greater in SISCOM than in side-by-side comparison. Logistic regression analysis showed the highest odds ratio of 12.391 (95% confidence interval; 3.319, 46.254) by SISCOM evaluation for concordance of the epileptogenic focus with the surgical site in predicting good surgical outcome.ConclusionsA SISCOM technique of ictal and interictal SPECT images provides higher predictive value of good surgical outcome and more reliability on the diagnosis of the epileptogenic focus than side-by-side comparison in medically intractable partial epilepsy.


International Journal of Geriatric Psychiatry | 2015

Comparison of imaging biomarkers for Alzheimer's disease: amyloid imaging with [18F]florbetapir positron emission tomography and magnetic resonance imaging voxel-based analysis for entorhinal cortex atrophy.

Amane Tateno; Takeshi Sakayori; Yoshitaka Kawashima; Makoto Higuchi; Tetsuya Suhara; Sunao Mizumura; Mark A. Mintun; Daniel Skovronsky; Kazuyoshi Honjo; Keiichi Ishihara; Shin-ichiro Kumita; Hidenori Suzuki; Yoshiro Okubo

We compared amyloid positron emission tomography (PET) and magnetic resonance imaging (MRI) in subjects clinically diagnosed with Alzheimers disease (AD), mild cognitive impairment (MCI), and older healthy controls (OHC) in order to test how these imaging biomarkers represent cognitive decline in AD.


Psychiatry and Clinical Neurosciences | 2011

Cerebral blood flow changes in very-late-onset schizophrenia-like psychosis with catatonia before and after successful treatment.

Naohisa Tsujino; Takahiro Nemoto; Taiju Yamaguchi; Naoyuki Katagiri; Nao Tohgi; Ryu Ikeda; Nobuyuki Shiraga; Sunao Mizumura; Masafumi Mizuno

The purpose of the present study was to investigate regional cerebral blood flow (rCBF) changes in a patient with very‐late‐onset schizophrenia‐like psychosis (VLOS) with catatonia. A 64‐year‐old woman developed catatonia after experiencing persecutory delusions. The patients rCBF was examined using single photon emission computed tomography (SPECT) with easy Z‐score imaging system. Before treatment, hypoperfusion was observed in the striatum and the thalamus, whereas hyperperfusion was observed in the left lateral frontal cortex and the left temporal cortex. After treatment, the disproportions in rCBF disappeared, and hyperperfusion was observed in the motor cortex. Sequential SPECT findings suggest that rCBF abnormalities may be correlated with the symptomatology of catatonia in patients with VLOS.


Psychiatry and Clinical Neurosciences | 2010

Regional cerebral blood flow in patients with orally localized somatoform pain disorder: a single photon emission computed tomography study

Hiroyuki Karibe; Ryosuke Arakawa; Amane Tateno; Sunao Mizumura; Tomoo Okada; Takashi Ishii; Katsuo Oshima; Mitsuhiro Ohtsu; Isao Hasegawa; Yoshiro Okubo

Aim:u2002 Somatoform pain disorder is characterized by persistent and chronic pain at one or more sites without an associated general medical condition and in which psychological factors are thought to play a role. This study aimed to investigate the pathological features of somatoform pain disorder localized to the oral region by single photon emission computed tomography (SPECT).


Journal of Stroke & Cerebrovascular Diseases | 2014

Combined Treatment of Methylprednisolone Pulse and Memantine Hydrochloride Prompts Recovery from Neurological Dysfunction and Cerebral Hypoperfusion in Carbon Monoxide Poisoning: A Case Report

Konosuke Iwamoto; Ken Ikeda; Sunao Mizumura; Kazuhiro Tachiki; Masaru Yanagihashi; Yasuo Iwasaki

A 49-year-old healthy man developed sudden unconsciousness under inadequate ventilation. Blood gas analysis showed carboxyhemoglobin of 7.3%. After normobaric oxygen therapy, he recovered completely 7 days later. At 3 weeks after carbon monoxide (CO) exposures, memory and gait disturbances appeared. Neurological examination revealed Mini-Mental State Examination (MMSE) score of 5 of 30 points, leg hyper-reflexia with Babinski signs, and Parkinsonism. Brain fluid-attenuated inversion recovery imaging disclosed symmetric hypointense lesions in the thalamus and the globus pallidus, and hyperintense lesions in the cerebral white matter. Brain single-photon emission tomography (SPECT) scanning with (99m)Technesium-ethyl cysteinate dimer displayed marked hypoperfusion in the cerebellum, the thalamus, the basal ganglia, and the entire cerebral cortex. He was diagnosed as CO poisoning and treated with hyperbaric oxygen therapy. The neurological deficits were not ameliorated. At 9 weeks after neurological onset, methylprednisolone (1000 mg/day, intravenous, 3 days) and memantine hydrochloride (20 mg/day, per os) were administered. Three days later, MMSE score was increased from 3 to 20 points. Neurological examination was normal 3 weeks later. Brain SPECT exhibited 20% increase of regional cerebral blood flows in the cerebellum, the thalamus, the basal ganglia, and the entire cerebral cortex. These clinicoradiological changes supported that the treatment with steroid pulse and memantine hydrochloride could prompt recovery from neurological dysfunction and cerebral hypoperfusion. Further clinical trials are warranted whether such combined therapy can attenuate neurological deficits and cerebral hypoperfusion in patients with CO poisoning.


Annals of Nuclear Medicine | 2013

Voxel-based analysis of 201Tl SPECT for grading and diagnostic accuracy of gliomas: comparison with ROI analysis

Tomoyuki Kuwako; Sunao Mizumura; Ryusuke Murakami; Tamiko Yoshida; Masato Shiiba; Hidetaka Sato; Yoshimitsu Fukushima; Akira Teramoto; Shin-ichiro Kumita

PurposeThe aim of this retrospective study was to assess the utility of a voxel-based analysis (VBA) method for 201Tl SPECT in glioma, compared to conventional ROI analysis.MethodsWe recruited 24 patients with glioma (high-grade 15; low-grade 9), for whom pre-operative 201Tl SPECT and MRI were performed. SPECT images were coregistered with MRI. The uptake ratio (UR) images of tumor to contralateral normal tissue were measured on early and delayed images, and the 201Tl retention index (RI) map was calculated from the early and delayed uptake ratio maps. In the ROI analysis, tumors were traced on a UR map, and the mean and maximal uptake ratio values on the early images were, respectively, defined as the mean and maximal UR. The mean and maximal RI values (mean and maximal RI) were calculated by division of the mean and maximal UR, respectively, on the delayed image by the mean and maximal UR on the early image. For the RI map calculated voxel by voxel, the maximal RI value was defined as VBA-RI. We evaluated sensitivity and accuracy of differential analysis with the mean and maximal UR, RI, and VBA-RI.ResultsThe high- and low-grade groups showed no significant difference in mean and maximal RI (0.98xa0±xa00.12 vs. 1.05xa0±xa00.09 and 0.98xa0±xa00.18 vs. 1.05xa0±xa00.14, respectively). The AUC and accuracy of the mean and maximal RI were 0.681 and 66.7xa0%, and 0.622 and 62.5xa0%, respectively. In contrast, VBA-RI was higher in high-grade than in low-grade glioma (1.69xa0±xa00.27 vs. 0.68xa0±xa00.66, pxa0<xa00.001). The AUC and accuracy of VBA-RI were 0.963 and 95.8xa0%, which are higher than those obtained for mean (pxa0<xa00.05) and maximal RI (pxa0<xa00.01). There was no significant difference in ROC between the VBA-RI and the mean UR (0.911, pxa0=xa00.456) and maximal UR (0.933, pxa0=xa00.639); however, the AUC, sensitivity, and diagnostic accuracy of VBA-RI were all higher than those of the mean and maximal UR.ConclusionThe voxel-based analysis method of 201Tl SPECT may improve diagnostic performance for gliomas, compared with ROI analysis.


Annals of Nuclear Medicine | 2018

Improvement in the measurement error of the specific binding ratio in dopamine transporter SPECT imaging due to exclusion of the cerebrospinal fluid fraction using the threshold of voxel RI count

Sunao Mizumura; Kazuhiro Nishikawa; Akihiro Murata; Kosei Yoshimura; Nobutomo Ishii; Tadashi Kokubo; Miyako Morooka; Akiko Kajiyama; Atsuro Terahara

ObjectiveIn Japan, the Southampton method for dopamine transporter (DAT) SPECT is widely used to quantitatively evaluate striatal radioactivity. The specific binding ratio (SBR) is the ratio of specific to non-specific binding observed after placing pentagonal striatal voxels of interest (VOIs) as references. Although the method can reduce the partial volume effect, the SBR may fluctuate due to the presence of low-count areas of cerebrospinal fluid (CSF), caused by brain atrophy, in the striatal VOIs. We examined the effect of the exclusion of low-count VOIs on SBR measurement.MethodsWe retrospectively reviewed DAT imaging of 36 patients with parkinsonian syndromes performed after injection of 123I-FP-CIT. SPECT data were reconstructed using three conditions. We defined the CSF area in each SPECT image after segmenting the brain tissues. A merged image of gray and white matter images was constructed from each patient’s magnetic resonance imaging (MRI) to create an idealized brain image that excluded the CSF fraction (MRI-mask method). We calculated the SBR and asymmetric index (AI) in the MRI-mask method for each reconstruction condition. We then calculated the mean and standard deviation (SD) of voxel RI counts in the reference VOI without the striatal VOIs in each image, and determined the SBR by excluding the low-count pixels (threshold method) using five thresholds: mean-0.0SD, mean-0.5SD, mean-1.0SD, mean-1.5SD, and mean-2.0SD. We also calculated the AIs from the SBRs measured using the threshold method. We examined the correlation among the SBRs of the threshold method, between the uncorrected SBRs and the SBRs of the MRI-mask method, and between the uncorrected AIs and the AIs of the MRI-mask method.ResultsThe intraclass correlation coefficient indicated an extremely high correlation among the SBRs and among the AIs of the MRI-mask and threshold methods at thresholds between mean-2.0D and mean-1.0SD, regardless of the reconstruction correction. The differences among the SBRs and the AIs of the two methods were smallest at thresholds between man-2.0SD and mean-1.0SD.ConclusionThe SBR calculated using the threshold method was highly correlated with the MRI–SBR. These results suggest that the CSF correction of the threshold method is effective for the calculation of idealized SBR and AI values.


The Journal of Nuclear Medicine | 2017

Prognostic value of 123 I-betamethyl-p-iodophenyl-pentadecanoic acid single-photon emission computed tomography in patients with non-ischemic heart failure with preserved ejection fraction

Hidenobu Hashimoto; Rine Nakanishi; Sunao Mizumura; Yukiko Hashimoto; Yuriko Okamura; Shunsuke Kiuchi; Junichi Yamazaki; Takanori Ikeda

Imaging of myocardial fatty acid metabolism using 123I-betamethyl-p-iodophenyl-pentadecanoic acid (123I-BMIPP) SPECT is useful for identifying high-risk patients with known ischemic heart disease. However, its utility for patients who have nonischemic heart failure with preserved ejection fraction is not well known. This study aimed to evaluate the prognostic value of the 123I-BMIPP defect score in such patients. Methods: Of 804 consecutive patients who were admitted to the hospital because of acute heart failure and underwent 123I-BMIPP SPECT, we identified 133 (mean age ± SD, 73 ± 13 y) who had normal coronary arteries by invasive coronary angiography and preserved left ventricular ejection fraction (≥50%) by echocardiography. 123I-BMIPP defects were quantitatively scored to obtain summed defect scores in 17 segments of 123I-BMIPP SPECT images. The patients were divided into 2 groups based on their score. The multivariate Cox model was used to assess a possible correlation between a higher score (≥4, n = 46) and major adverse cardiac events, including cardiac death, cardiovascular events, and hospitalization for heart failure, compared with a lower score (<4, n = 87). Results: During a mean follow-up of 2.5 y, 35 major adverse cardiac events occurred. The median scores in the high-score and low-score groups were 7.13 ± 4.21 and 1.29 ± 0.80, respectively. By multivariate Cox analysis, a higher score was associated with increased major adverse cardiac events, compared with a lower score (hazard ratio, 11.04; 95% confidence interval, 4.93–24.74; P < 0.001). Conclusion: This study demonstrated that the defect score by 123I-BMIPP SPECT may have potential prognostic value in patients who have nonischemic heart failure with preserved ejection fraction.


American Journal of Neuroradiology | 2007

Automated Discrimination Between Very Early Alzheimer Disease and Controls Using an Easy Z-Score Imaging System for Multicenter Brain Perfusion Single-Photon Emission Tomography

Hiroshi Matsuda; Sunao Mizumura; T. Nagao; Tsuneyoshi Ota; T. Iizuka; Kiyotaka Nemoto; N. Takemura; Heii Arai; A. Homma

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Hiroshi Matsuda

Saitama Medical University

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Etsuko Imabayashi

Saitama Medical University

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