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Your search keyword '"Yoshikawa, Etsuji"' showing total 244 results
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244 results on '"Yoshikawa, Etsuji"'

1. Neural substrates of cough control during coughing

Author

Sugi, Takafumi, Inubushi, Tomoo, Ohno, Tomohisa, Onishi, Yuya, Isobe, Takashi, Shigematsu, Takashi, Hanai, Satoshi, Okada, Yoshiro, Takahashi, Ryosuke, Tawara, Yuichi, Suzuki, Chie, Kanno, Toshihiko, Magata, Yasuhiro, Fujishima, Ichiro, Yoshikawa, Etsuji, and Ouchi, Yasuomi

Published
2024
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2. Anatomical-Guided Attention Enhances Unsupervised PET Image Denoising Performance

Author

Onishi, Yuya, Hashimoto, Fumio, Ote, Kibo, Ohba, Hiroyuki, Ota, Ryosuke, Yoshikawa, Etsuji, and Ouchi, Yasuomi

Subjects
Physics - Medical Physics, Computer Science - Computer Vision and Pattern Recognition, Computer Science - Machine Learning
Abstract

Although supervised convolutional neural networks (CNNs) often outperform conventional alternatives for denoising positron emission tomography (PET) images, they require many low- and high-quality reference PET image pairs. Herein, we propose an unsupervised 3D PET image denoising method based on an anatomical information-guided attention mechanism. The proposed magnetic resonance-guided deep decoder (MR-GDD) utilizes the spatial details and semantic features of MR-guidance image more effectively by introducing encoder-decoder and deep decoder subnetworks. Moreover, the specific shapes and patterns of the guidance image do not affect the denoised PET image, because the guidance image is input to the network through an attention gate. In a Monte Carlo simulation of [$^{18}$F]fluoro-2-deoxy-D-glucose (FDG), the proposed method achieved the highest peak signal-to-noise ratio and structural similarity (27.92 $\pm$ 0.44 dB/0.886 $\pm$ 0.007), as compared with Gaussian filtering (26.68 $\pm$ 0.10 dB/0.807 $\pm$ 0.004), image guided filtering (27.40 $\pm$ 0.11 dB/0.849 $\pm$ 0.003), deep image prior (DIP) (24.22 $\pm$ 0.43 dB/0.737 $\pm$ 0.017), and MR-DIP (27.65 $\pm$ 0.42 dB/0.879 $\pm$ 0.007). Furthermore, we experimentally visualized the behavior of the optimization process, which is often unknown in unsupervised CNN-based restoration problems. For preclinical (using [$^{18}$F]FDG and [$^{11}$C]raclopride) and clinical (using [$^{18}$F]florbetapir) studies, the proposed method demonstrates state-of-the-art denoising performance while retaining spatial resolution and quantitative accuracy, despite using a common network architecture for various noisy PET images with 1/10th of the full counts. These results suggest that the proposed MR-GDD can reduce PET scan times and PET tracer doses considerably without impacting patients., Comment: 30 pages, 12 figures

Published
2021
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13. Brain serotonin and dopamine transporter bindings in adults with high-functioning autism

Author

Nakamura, Kazuhiko, Sekine, Yoshimoto, Ouichi, Yasuomi, Tsujii, Masutsugu, Yoshikawa, Etsuji, Futatsubashi, Masami, Tsuchiya, Kenji J., Sugihara, Genichi, Iwata, Yasuhide, Suzuki, Katsuaki, Matsuzaki, Hideo, Suda, Shiro, Sugiyama, Toshiro, Takei, Nori, and Mori, Norio

Subjects
Autism -- Development and progression, Autism -- Research, Autism -- Demographic aspects, Serotonin metabolism -- Physiological aspects, Serotonin metabolism -- Research, Dopaminergic mechanisms -- Physiological aspects, Dopaminergic mechanisms -- Research, Health, Psychology and mental health
Published
2010

14. Brain serotonin transporter density and aggression in abstinent methamphetamine abusers

Author

Sekine, Yoshimoto, Ouchi, Yasuomi, Takei, Nori, Yoshikawa, Etsuji, Nakamura, Kazuhiko, Futatsubashi, Masami, Okada, Hiroyuki, Minabe, Yoshio, Suzuki, Katsuaki, Iwata, Yasuhide, Tsuchiya, Kenji J., Tsukada, Hideo, Iyo, Masaomi, and Mori, Norio

Subjects
Serotonin -- Research, Methamphetamine -- Complications and side effects, Drug withdrawal symptoms -- Evaluation, Aggressiveness (Psychology) -- Physiological aspects, Health, Psychology and mental health
Published
2006

22. In vivo imaging of dopamine D1 receptor and activated microglia in attention-deficit/hyperactivity disorder: a positron emission tomography study

Author

Yokokura, Masamichi, primary, Takebasashi, Kiyokazu, additional, Takao, Akiyo, additional, Nakaizumi, Kyoko, additional, Yoshikawa, Etsuji, additional, Futatsubashi, Masami, additional, Suzuki, Katsuaki, additional, Nakamura, Kazuhiko, additional, Yamasue, Hidenori, additional, and Ouchi, Yasuomi, additional

Published
2020
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41. F148. A PILOT STUDY OF [11C] (R)-MEQAA PET BRAIN IMAGING ANALYSIS OF ALPHA 7 NICOTINIC ACETYLCHOLINE RECEPTORS AVAILABILITY IN SCHIZOPHRENIA

Author

Wakuda, Tomoyasu, primary, Yokokura, Masamichi, additional, Nakaizumi, Kyoko, additional, Kato, Yasuhiko, additional, Kameno, Yosuke, additional, Futatsubashi, Masami, additional, Yoshikawa, Etsuji, additional, Magata, Yasuhiro, additional, Ouchi, Yasuomi, additional, Yamasue, Hidenori, additional, and Takei, Nori, additional

Published
2018
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45. A pilot study of serotonergic modulation after long‐term administration of oxytocin in autism spectrum disorder

Author

Hirosawa, Tetsu, primary, Kikuchi, Mitsuru, additional, Ouchi, Yasuomi, additional, Takahashi, Tetsuya, additional, Yoshimura, Yuko, additional, Kosaka, Hirotaka, additional, Furutani, Naoki, additional, Hiraishi, Hirotoshi, additional, Fukai, Mina, additional, Yokokura, Masamichi, additional, Yoshikawa, Etsuji, additional, Bunai, Tomoyasu, additional, and Minabe, Yoshio, additional

Published
2017
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46. Biopathological Significance of Early-Phase Amyloid Imaging in the Spectrum of Alzheimer's Disease.

Author

Cook, David, Bunai, Tomoyasu, Ouchi, Yasuomi, Terada, Tatsuhiro, Kakimoto, Akihiro, and Yoshikawa, Etsuji

Subjects
ALZHEIMER'S disease, POSITRON emission tomography, AMYLOID, ALZHEIMER'S disease diagnosis, MILD cognitive impairment
Abstract

Background: Amyloid imaging with positron emission tomography (PET) often comes with glucose metabolic imaging in diagnosis of Alzheimer's disease (AD).Objective: The present purpose was to explore the clinical valence of early amyloid-β (Aβ) PET scans to determine whether they could substitute for other imaging biomarkers (early and delayed Aβ images of 11C-Pittsburgh compound B (PIB) and 18F-fluorodeoxyglucose (FDG) images) in the AD spectrum.Methods: Thirty healthy control subjects, 20 patients with mild cognitive impairment, and 45 patients with AD underwent 11C-PIB and 18F- FDG PET. Image analyses were performed with three-dimensional stereotactic surface projection and Brodmann's area regions-of-interest methods. Since early accumulation of PIB (ePIB) reflects blood flow, we classified all subjects according to the level of ePIB in the posterior cingulate gyrus, precuneus, and lateral parietal cortex. We compared the PET parameters (ePIB, delayed-phase PIB accumulation or dPIB, FDG) to determine whether ePIB-based categorization reflected Aβ deposition in a Braak stage-related fashion.Results: We found that ePIB images were similar to 18F-FDG images and that the progress of Aβ deposition deduced from the reduction in ePIB index was similar to the pathological progress of Braak staging. A decrease in the ePIB level in the posterior cingulate gyrus, precuneus, and parietal cortex was shown to correspond to greater and wider Aβ deposition in the medial frontal, anterior, and posterior cingulate gyri.Conclusions: The early-phase 11C-PIB index can be an alternative to the neurogenerative markers of glucose hypometabolism and reflects the Braak stage of Aβ deposition in the living AD brain. [ABSTRACT FROM AUTHOR]

Published
2019
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48. Depiction of microglial activation in aging and dementia: Positron emission tomography with [11C]DPA713 versus [11C](R)PK11195

Author

Yokokura, Masamichi, primary, Terada, Tatsuhiro, additional, Bunai, Tomoyasu, additional, Nakaizumi, Kyoko, additional, Takebayashi, Kiyokazu, additional, Iwata, Yasuhide, additional, Yoshikawa, Etsuji, additional, Futatsubashi, Masami, additional, Suzuki, Katsuaki, additional, Mori, Norio, additional, and Ouchi, Yasuomi, additional

Published
2016
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49. In vivo Depiction of α7 Nicotinic Receptor Loss for Cognitive Decline in Alzheimer's Disease.

Author

Kyoko Nakaizumi, Yasuomi Ouci, Tatsuhiro Terad, Etsuji Yoshikawa, Akihiro Kakimoto, Takashi Isobe, Tomoyasu Bunai, Masamichi Yokokura, Katsuaki Suzuki, Yasuhiro Magata, Nakaizumi, Kyoko, Ouchi, Yasuomi, Terada, Tatsuhiro, Yoshikawa, Etsuji, Kakimoto, Akihiro, Isobe, Takashi, Bunai, Tomoyasu, Yokokura, Masamichi, Suzuki, Katsuaki, and Magata, Yasuhiro

Subjects
ALZHEIMER'S disease, COGNITION disorders, NICOTINIC acetylcholine receptors, ALZHEIMER'S patients, PATHOLOGICAL physiology, RADIOACTIVE tracers in physiology, CHOLINERGIC receptors, BRAIN, COMPARATIVE studies, RESEARCH methodology, MEDICAL cooperation, RESEARCH, POSITRON emission tomography, EVALUATION research, CASE-control method
Abstract

Background: The α7 subtype of the nicotinic acetylcholine receptor (nAChR) is considered important in higher cognitive functions, and cholinergic loss underpins the pathophysiology of Alzheimer's disease (AD). However, the relationships between α7 nAChR function and clinical functions or amyloid-β (Aβ) deposition remain to be explored in the living AD brain.Objective: We aimed to elucidate the relationship between α7 nAChR availability in the specific cholinergic region and cognitive decline in the Aβ-confirmed AD brain.Methods: Twenty AD patients and ten age-matched healthy subjects were examined. The α7-nAChR availability and Aβ deposition were evaluated using positron emission tomography with an α7 nAChR radiotracer 11C-(R)-MeQAA and 11C-Pittsburg compound B (11C-PiB), respectively. Semi-quantified values of tracer binding were estimated with a simplified reference tissue method for BPND of 11C-(R)-MeQAA and a tissue ratio method for SUVR of 11C-PiB. These parameters and clinical scores were compared voxel-wise using a statistical parametric mapping method.Results: The levels of 11C-(R)-MeQAA BPND in the temporal and prefrontal cholinergic projection regions were significantly lower in AD, and negative correlations were found between 11C-PiB SUVR and 11C-(R)-MeQAA BPND in the region of the nucleus basalis magnocellularis and medial prefrontal cortex. Levels of 11C-(R)-MeQAA BPND were significantly correlated with memory and frontal function scores in AD.Conclusion: The association between Aβ burden and α7-nAChR reduction in the basal forebrain cholinergic system was highlighted in relation to cognitive decline in AD. This suggests that Aβ-linked α7-nAChR reduction is clinico-pathophyisologically important for considering a good therapeutic target in AD. [ABSTRACT FROM AUTHOR]

Published
2018
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