2021/05/15 更新

写真a

オオクボ マサキ
大久保 真樹
OHKUBO Masaki
所属
教育研究院 医歯学系 保健学系列 教授
医学部 保健学科 教授
保健学研究科 保健学専攻 教授
職名
教授
外部リンク

学位

  • 博士(医学) ( 1994年6月   新潟大学 )

  • 工学修士 ( 1988年3月   新潟大学 )

研究分野

  • その他 / その他

経歴

  • 新潟大学   保健学研究科 保健学専攻   教授

    2013年4月 - 現在

  • 新潟大学   医学部 保健学科   教授

    2013年4月 - 現在

  • 新潟大学   保健学研究科 保健学専攻   准教授

    2004年4月 - 2013年3月

  • 新潟大学   医学部 保健学科   助教授

    1999年10月 - 2004年3月

  • 新潟大学   医療技術短期大学部   助教授

    1997年4月 - 1999年9月

  • 新潟大学   医療技術短期大学部   助手

    1988年4月 - 1997年3月

▶ 全件表示

所属学協会

 

論文

  • Advances and Challenges in Assessing 2-Hydroxyglutarate in Gliomas by Magnetic Resonance Spectroscopy: A Short Review 査読

    Neuropsychiatry (London)8 ( 6 ) 1831 - 1838   2018年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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  • Improved wedge method for the measurement of sub-millimeter slice thicknesses in magnetic resonance imaging 査読

    Tsutomu Kanazawa, Masaki Ohkubo, Tatsuya Kondo, Takayuki Miyazawa, Shoichi Inagawa

    Radiological Physics and Technology10 ( 4 ) 446 - 453   2017年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Springer Tokyo  

    The standard method for measuring the slice thickness of magnetic resonance images uses the inclined surface of a wedge (wedge method)
    it is sensitive to small increases in noise because of the differentiation of the edge response function (ERF) required. The purpose of this study was to improve the wedge method by fitting a curve to the ERF. The curve-fit function was obtained by convolving an ideal ERF (a ramp function) with a Gaussian function to represent ERF blurring. Measurements of 5- and 3-mm slice thicknesses were performed on a 3T scanner using the conventional wedge method, the improved wedge method, and another standard method using an inclined slab (slab method). Subsequently, 0.5- and 0.25-mm slice thicknesses from multiple slices acquired using a three-dimensional sequence were measured using the improved wedge method. When measuring 5-mm slices, the differences in measurements obtained using the improved wedge method and the conventional slab and wedge methods were very small: &lt
    0.6% of the 5-mm slice thickness. The difference was ≤1.7% for 3-mm slices. For 0.5- and 0.25-mm slices, the mean values obtained using the improved wedge method were 0.543 ± 0.007 mm and 0.247 ± 0.015 mm, with a 1.2 and 5.9% coefficient of variation across slices, respectively. The improved wedge method is valid and potentially applicable to the measurement of sub-millimeter slice thicknesses.

    DOI: 10.1007/s12194-017-0417-2

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  • Generation of realistic virtual nodules based on three-dimensional spatial resolution in lung computed tomography: A pilot phantom study 査読

    Akihiro Narita, Masaki Ohkubo, Kohei Murao, Toru Matsumoto, Shinichi Wada

    MEDICAL PHYSICS44 ( 10 ) 5303 - 5313   2017年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY  

    Purpose: The aim of this feasibility study using phantoms was to propose a novel method for obtaining computer-generated realistic virtual nodules in lung computed tomography (CT).
    Methods: In the proposed methodology, pulmonary nodule images obtained with a CT scanner are deconvolved with the point spread function (PSF) in the scan plane and slice sensitivity profile (SSP) measured for the scanner; the resultant images are referred to as nodule-like object functions. Next, by convolving the nodule-like object function with the PSF and SSP of another (target) scanner, the virtual nodule can be generated so that it has the characteristics of the spatial resolution of the target scanner. To validate the methodology, the authors applied physical nodules of 5-, 7- and 10-mm-diameter (uniform spheres) included in a commercial CT test phantom. The nodule-like object functions were calculated from the sphere images obtained with two scanners (Scanner A and Scanner B); these functions were referred to as nodule-like object functions A and B, respectively. From these, virtual nodules were generated based on the spatial resolution of another scanner (Scanner C). By investigating the agreement of the virtual nodules generated from the nodule-like object functions A and B, the equivalence of the nodule-like object functions obtained from different scanners could be assessed. In addition, these virtual nodules were compared with the real (true) sphere images obtained with Scanner C. As a practical validation, five types of laboratory-made physical nodules with various complicated shapes and heterogeneous densities, similar to real lesions, were used. The nodule-like object functions were calculated from the images of these laboratory-made nodules obtained with Scanner A. From them, virtual nodules were generated based on the spatial resolution of Scanner C and compared with the real images of laboratory-made nodules obtained with Scanner C.
    Results: Good agreement of the virtual nodules generated from the nodule-like object functions A and B of the phantom spheres was found, suggesting the validity of the nodule-like object functions. The virtual nodules generated from the nodule-like object function A of the phantom spheres were similar to the real images obtained with Scanner C; the root mean square errors (RMSEs) between them were 10.8, 11.1, and 12.5 Hounsfield units (HU) for 5-, 7-, and 10-mm-diameter spheres, respectively. The equivalent results (RMSEs) using the nodule-like object function B were 15.9, 16.8, and 16.5 HU, respectively. These RMSEs were small considering the high contrast between the sphere density and background density (approximately 674 HU). The virtual nodules generated from the nodule-like object functions of the five laboratory-made nodules were similar to the real images obtained with Scanner C; the RMSEs between them ranged from 6.2 to 8.6 HU in five cases.
    Conclusions: The nodule-like object functions calculated from real nodule images would be effective to generate realistic virtual nodules. The proposed method would be feasible for generating virtual nodules that have the characteristics of the spatial resolution of the CT system used in each institution, allowing for site-specific nodule generation. (C) 2017 American Association of Physicists in Medicine

    DOI: 10.1002/mp.12503

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  • Magnetic Resonance Imaging of Neurotransmitter-Related Molecules 査読

    Hironaka Igarashi, Satoshi Ueki, Ken Ohno, Masaki Ohkubo, Yuji Suzuki

    JOURNAL OF NIPPON MEDICAL SCHOOL84 ( 4 ) 160 - 164   2017年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:MEDICAL ASSOC NIPPON MEDICAL SCH  

    Molecular imaging implies the method capable of pictorially displaying distribution of target molecules and their relative concentration in space. In clinical medicine, where non-invasiveness is mandatory, diagnostic molecular imaging has been considered virtually identical to positron emission tomography (PET). However, there is another powerful, apparently underutilized molecular imaging, namely, proton magnetic resonance spectroscopic imaging (H-1-MRSI). The technique can detect target molecules endogenous in brain in virtue of their own specific resonance frequencies (chemical shift) and can create quantitative images of each molecule. H-1-MRSI is conventionally utilized for imaging relatively easily detectable molecules such as N-acetyl-aspartate or lactate. More recently, however, the method is extended into imaging of more challenging molecules such as glutamate or gamma-aminobutyric acid (GABA). In this small review, we summarize basic concept of H-1-MRSI and introduce an advanced technique, i.e. chemical exchange saturation transfer magnetic resonance imaging (CEST MRI), which made realistic glutamate imaging in vivo possible.

    DOI: 10.1272/jnms.84.160

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  • Measurement of thin slice thickness in MRI using an improved wedge method 査読

    Kanazawa T, Ohkubo M, Kondo T

    European Congress of RadiologyC-1063   1 - 14   2017年3月

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:European Society of Radiology  

    DOI: 10.1594/ecr2017/C-1063

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  • パーソナルコンピュータ上で動作するDICOMデータのCT画像からの体積測定プログラムの開発と評価(PC用のDICOM体積測定プログラムの開発と評価)(The development and assessment of program for volume measurement for CT images of: DICOM data running on a personal computer: (Development and assessment of volume measurement program for DICOM on PC)) 査読

    Takahashi Naoya, Kobayashi Arashi, Nishihama Saori, Minamizawa Natsuki, Suzuki Noriko, Higuchi Takeshi, Ohkubo Masaki, Narita Akihiro, Sasamoto Ryuta

    新潟大学保健学雑誌14 ( 1 ) 27 - 33   2017年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:新潟大学医学部保健学科  

    著者等は数値計算言語(MATLAB)を使ってPC上で動作するDICOM画像から体積を算出するプログラムを開発し、その有用性と正確度を検討した。CTの水平断像上に関心領域(ROI)を設置し、設定した閾値で必要な領域を抽出して三次元表示し、体積測定を行うこととした。本プログラムを用いて、64列CTで実施した死後CT検査5例について、肝、脾、腎を抽出した。ImageJにて目的とする臓器にROIを設定して面積を算出し、厚さを乗じて体積を測定した。臓器ごとに、ImageJにて求めた体積に最も近い値が得られるように閾値を決定した。著者等が開発したプログラムとImageJで測定した平均体積は、肝がそれぞれ1690.3±505.1cm3と107.9±60.7cm3、脾が107.9±60.7cm3と105.5±62.4cm3、腎が141.1±26.4cm3と143.9±32.1cm3であり、有意差は認められなかった。体積測定に要した平均時間は開発したプログラムの方が有意に短かった。著者等が開発したPC上で動作するDICOM画像の体積測定プログラムを用いると、簡便かつ正確に臓器の体積を測定することが可能であった。

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    その他リンク: http://dspace.lib.niigata-u.ac.jp/dspace/bitstream/10191/47194/1/14%281%29_27-33.pdf

  • A method for evaluating the performance of computeraided detection of pulmonary nodules in lung cancer CT screening: detection limit for nodule size and density 査読

    Hajime Kobayashi, Masaki Ohkubo, Akihiro Narita, Janaka C. Marasinghe, Kohei Murao, Toru Matsumoto, Shusuke Sone, Shinichi Wada

    BRITISH JOURNAL OF RADIOLOGY90 ( 1070 ) 1 - 10   2017年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:BRITISH INST RADIOLOGY  

    Objective: We propose the application of virtual nodules to evaluate the performance of computer-aided detection (CAD) of lung nodules in cancer screening using lowdose CT.
    Methods: The virtual nodules were generated based on the spatial resolution measured for a CT system used in an institution providing cancer screening and were fused into clinical lung images obtained at that institution, allowing site specificity. First, we validated virtual nodules as an alternative to artificial nodules inserted into a phantom. In addition, we compared the results of CAD analysis between the real nodules (n=6) and the corresponding virtual nodules. Subsequently, virtual nodules of various sizes and contrasts between nodule density and background density (Delta CT) were inserted into clinical images (n=10) and submitted for CAD analysis.
    Results: In the validation study, 46 of 48 virtual nodules had the same CAD results as artificial nodules (kappa coefficient = 0.913). Real nodules and the corresponding virtual nodules showed the same CAD results. The detection limits of the tested CAD system were determined in terms of size and density of peripheral lung nodules; we demonstrated that a nodule with a 5- mm diameter was detected when the nodule had a Delta CT> 220 HU.
    Conclusion: Virtual nodules are effective in evaluating CAD performance using site-specific scan/reconstruction conditions.
    Advances in knowledge: Virtual nodules can be an effectivemeans of evaluating site-specific CAD performance. The methodology for guiding the detection limit for nodule size/density might be a useful evaluation strategy.

    DOI: 10.1259/bjr.20160313

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  • Technical Note: Image filtering to make computer-aided detection robust to image reconstruction kernel choice in lung cancer CT screening 査読

    Masaki Ohkubo, Akihiro Narita, Shinichi Wada, Kohei Murao, Toru Matsumoto

    MEDICAL PHYSICS43 ( 7 ) 4098 - 4105   2016年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICS  

    Purpose: In lung cancer computed tomography (CT) screening, the performance of a computer-aided detection (CAD) system depends on the selection of the image reconstruction kernel. To reduce this dependence on reconstruction kernels, the authors propose a novel application of an image filtering method previously proposed by their group.
    Methods: The proposed filtering process uses the ratio of modulation transfer functions (MTFs) of two reconstruction kernels as a filtering function in the spatial-frequency domain. This method is referred to as MTFratio filtering. Test image data were obtained from CT screening scans of 67 subjects who each had one nodule. Images were reconstructed using two kernels: f(STD) (for standard lung imaging) and f(SHARP) (for sharp edge-enhancement lung imaging). The MTFratio filtering was implemented using the MTFs measured for those kernels and was applied to the reconstructed f(SHARP) images to obtain images that were similar to the f(STD) images. A mean filter and a median filter were applied (separately) for comparison. All reconstructed and filtered images were processed using their prototype CAD system.
    Results: The MTFratio filtered images showed excellent agreement with the f(STD) images. The standard deviation for the difference between these images was very small, similar to 6.0 Hounsfield units (HU). However, the mean and median filtered images showed larger differences of similar to 48.1 and similar to 57.9 HU from the f(STD) images, respectively. The free-response receiver operating characteristic (FROC) curve for the f(SHARP) images indicated poorer performance compared with the FROC curve for the f(STD) images. The FROC curve for the MTFratio filtered images was equivalent to the curve for the f(STD) images. However, this similarity was not achieved by using the mean filter or median filter.
    Conclusions: The accuracy of MTFratio image filtering was verified and the method was demonstrated to be effective for reducing the kernel dependence of CAD performance. (C) 2016 American Association of Physicists in Medicine.

    DOI: 10.1118/1.4953247

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  • Interventional Radiology 装置の線量率測定における留意点 査読

    吉田秀義, 高橋千春, 成田信浩, 水沢康彦, 関谷 勝, 大久保真樹

    日本放射線技術学会雑誌72 ( 1 ) 63 - 72   2016年1月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.6009/jjrt.2016_JSRT_72.1.63

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  • Characterization of the model-based iterative reconstruction algorithm: Confirmation of coexistence of dose reduction and spatial resolution improvement 査読

    Kayugawa A, Noto Y, Taga T, Fukaya T, Tasaki K, Fujioka T, Ohkubo M

    European Congress of RadiologyC-0946   1 - 24   2015年3月

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:European Society of Radiology  

    DOI: 10.1594/ecr2015/C-0946

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  • Quality assurance of lung cancer CT screening CAD system by applying PSF-based reference virtual nodule set 査読

    Marasinghe JC, Ohkubo M, Kobayashi H, Yoshida A, Murao K, Matsumoto T, Sone S, Wada S

    European Congress of RadiologyC-1125   1 - 11   2015年3月

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:European Society of Radiology  

    DOI: 10.1594/ecr2015/C-1125

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  • Diffuse Brain Abnormalities in Myotonic Dystrophy Type 1 Detected by 3.0 T Proton Magnetic Resonance Spectroscopy 査読

    Yuhei Takado, Kenshi Terajima, Masaki Ohkubo, Kouichirou Okamoto, Takayoshi Shimohata, Masatoyo Nishizawa, Hironaka Igarashi, Tsutomu Nakada

    EUROPEAN NEUROLOGY73 ( 3-4 ) 247 - 256   2015年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:KARGER  

    Patients with myotonic dystrophy type 1 (DM1) (n = 14) were compared with healthy controls (n = 13) using 3.0 T proton magnetic resonance spectroscopy (H-1-MRS) to investigate brain pathophysiology. H-1-MRS imaging revealed reduced N-acetylaspartate to creatine ratio (NAA/Cr) in multiple brain regions (average 24%), suggesting diffuse brain abnormalities among patients with DM1. Single-voxel H-1-MRS among patients with DM1 showed (1) reduced NAA in both the frontal cortex (23%) and frontal white matter (31%) and unaltered myo-inositol, suggesting neuronal abnormalities without significant gliosis; and (2) elevated glutamine in the frontal cortex (36%) and reduced glutamate in the frontal white matter (20%) among patients with DM1, suggesting abnormalities in the glutamatergic system in the brain of patients with DM1. We consider that these results reflect brain abnormalities that cannot be detected by neuropathological assessment in patients with DM1. (C) 2015 S. Karger AG, Basel

    DOI: 10.1159/000371575

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  • Validation of using PSF-based virtual nodules to assess the basic performances of lung cancer CT screening CAD system 査読

    Marasinghe JC, Ohkubo M, Wada S, Kobayashi H, Yoshida A, Murao K, Matsumoto T, Sone S

    Computer Assisted Radiology and Surgery 2014, 28th International and Exhibition9 ( 1 (S236) )   2014年6月

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:CARS 2014  

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  • Feasible method to assess the performance of a lung cancer CT screening CAD system in clinical practice: dependence on nodule size and density 査読

    Marasinghe JC, Ohkubo M, Kobayashi H, Murao K, Matsumoto T, Sone S, Wada S

    International Journal of Medical Physics, Clinical Engineering and Radiation Oncology3 ( 2 ) 107 - 116   2014年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.4236/ijmpcero.2014.32016

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  • [15O]H2O OSEM法PET画像でのsubset とiterationの組み合わせによる画素値の検討: FBP法を基準として 査読

    山野井理恵, 岡本浩一郎, 河村和紀, 大久保真樹, 鈴木雄治, 中村亨弥

    日本核医学会機関紙51 ( 4 ) 373 - 382   2014年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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  • Evaluation of lung CT CAD performance by using PSF-based virtual nodules: a validation of the methodology 査読

    Marasinghe JC, Ohkubo M, Kobayashi H, Murao K, Matsumoto T, Sone S, Wada S

    MEDICAL PHYSICS INTERNATIONAL Journal1 ( 2 ) 350 - 350   2013年9月

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:The International Conference on Medical Physics 2013 (ICMP 2013)  

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  • Observer-independent nodule-detectability index for low-dose lung cancer screening CT: A pilot study 査読

    Masaki Ohkubo, Shinichi Wada, Satoshi Kanai, Kazuhiro Ishikawa, Janaka C. Marasinghe, Toru Matsumoto

    Radiological Physics and Technology6 ( 2 ) 492 - 499   2013年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    For the wide dissemination of lung cancer screening by low-dose computed tomography (CT), it is important to determine the optimal conditions for scan and image reconstruction based on objective standards of evaluation. Our aim in this study was to propose a quantitative index of nodule detectability without an observer test. It was essential to determine the apparent size and density of nodules visible on CT images for developing the nodule-detectability index based on a statistical observer-independent method. Therefore, we introduced a computer simulation technique for CT images based on the spatial resolution of the system to evaluate the size and density accurately. By use of scan/reconstruction parameter settings as employed for low-dose CT screening, a detectability index was obtained for target nodules (ideal spheres) of various sizes and with varying contrast (ΔCT) between nodule density and background density. The index was compared with the qualitative results of observer tests of nodule detectability. As the target nodule diameter or ΔCT was increased, the index value increased, implying improved nodule visibility. According to the index, the detection limits for nodules with ΔCTs of 70, 100, or 150 Hounsfield units were approximately 6, 5, and 4 mm in diameter, respectively. Index values were well correlated with nodule detectability as assessed by four observers. The proposed index was effective for quantifying nodule detectability, and its validity was confirmed by an observer test. This index has potential use in the determination of optimal scan/reconstruction parameters for lung cancer screening by low-dose CT without observer test. © 2013 Japanese Society of Radiological Technology and Japan Society of Medical Physics.

    DOI: 10.1007/s12194-013-0225-2

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  • Accurate determination of ct point-spread-function with high precision 査読

    Akihiro Kayugawa, Masaki Ohkubo, Shinichi Wada

    Journal of Applied Clinical Medical Physics14 ( 4 ) 216 - 226   2013年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:John Wiley and Sons Ltd  

    The measurement of modulation transfer functions (MTFs) in computed tomography (CT) is often performed by scanning a point source phantom such as a thin wire or a microbead. In these methods the region of interest (ROI) is generally placed on the scanned image to crop the point source response. The aim of the present study was to examine the effect of ROI size on MTF measurement, and to optimize the ROI size. Using a 4 multidetector-row CT, MTFs were measured by the wire and bead methods for three types of reconstruction kernels designated as 'smooth', 'standard', and 'edge-enhancement' kernels. The size of a square ROI was changed from 30 to 50 pixels (approximately 2.9 to 4.9 mm). The accuracies of the MTFs were evaluated using the verification method. The MTFs measured by the wire and bead methods were dependent on ROI size, particularly in MTF measurement for the 'edge-enhancement' kernel. MTF accuracy evaluated by the verification method changed with ROI size, and we were able to determine the optimum ROI size for each method (wire/bead) and for each kernel. Using these optimal ROI sizes, the MTF obtained by the wire method was in strong agreement with the MTF obtained by the bead method in each kernel. Our data demonstrate that the difficulties in obtaining accurate MTFs for some kernels such as edge-enhancement can be overcome by incorporating the verification method into the wire and bead methods, allowing optimization of the ROI size to accurately determine the MTF.

    DOI: 10.1120/jacmp.v14i4.3905

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  • Application of PSF-based virtual nodules to assess the performance of lung cancer CT screening CAD system 査読

    Marasinghe JC, Ohkubo M, Kobayashi H, Murao K, Matsumoto T, Niizuma S, Sone S, Wada S

    Proceedings of Asia-Oceania Congress of Medical Physics12 ( 1 ) 249 - 252   2012年12月

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:12th Asia-Oceania Congress of Medical Physics (12th AOCMP)  

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  • Application of CT-PSF-based computer-simulated lung nodules for evaluating the accuracy of computer-aided volumetry 査読

    Ayumu Funaki, Masaki Ohkubo, Shinichi Wada, Kohei Murao, Toru Matsumoto, Shinji Niizuma

    Radiological Physics and Technology5 ( 2 ) 166 - 171   2012年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    With the wide dissemination of computed tomography (CT) screening for lung cancer, measuring the nodule volume accurately with computer-aided volumetry software is increasingly important. Many studies for determining the accuracy of volumetry software have been performed using a phantom with artificial nodules. These phantom studies are limited, however, in their ability to reproduce the nodules both accurately and in the variety of sizes and densities required. Therefore, we propose a new approach of using computer-simulated nodules based on the point spread function measured in a CT system. The validity of the proposed method was confirmed by the excellent agreement obtained between computer-simulated nodules and phantom nodules regarding the volume measurements. A practical clinical evaluation of the accuracy of volumetry software was achieved by adding simulated nodules onto clinical lung images, including noise and artifacts. The tested volumetry software was revealed to be accurate within an error of 20 % for nodules[5 mm and with the difference between nodule density and background (lung) (CT value) being 400-600 HU. Such a detailed analysis can provide clinically useful information on the use of volumetry software in CT screening for lung cancer. We concluded that the proposed method is effective for evaluating the performance of computer-aided volumetry software. © Japanese Society of Radiological Technology and Japan Society of Medical Physics 2012.

    DOI: 10.1007/s12194-012-0150-9

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  • 放射線治療における位置照合の容易化を目的としたEPID ポータル画像の周波数処理に関する検討 査読

    山田昌法, 大久保真樹, 粥川啓廣, 山田宏美, 松浦将孝, 三浦 貴, 楠本敏久

    日本放射線技術学会雑誌68 ( 5 ) 593 - 601   2012年5月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.6009/jjrt.2012_JSRT_68.5.593

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  • 脳動脈瘤クリップにおける磁化率アーチファクトの角度依存性の検討

    金沢 勉, 内藤健一, 斉藤宏明, 粥川啓廣, 岩崎友也, 大久保真樹, 木村元政

    日本放射線技術学会東北部会雑誌21   86 - 89   2012年1月

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    記述言語:日本語   掲載種別:研究論文(研究会,シンポジウム資料等)  

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  • Accuracy of lung nodule density on HRCT: analysis by PSF-based image simulation 査読

    Ken Ohno, Masaki Ohkubo, Janaka C. Marasinghe, Kohei Murao, Toru Matsumoto, Shinichi Wada

    JOURNAL OF APPLIED CLINICAL MEDICAL PHYSICS13 ( 6 ) 277 - 292   2012年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:MULTIMED INC  

    A computed tomography (CT) image simulation technique based on the point spread function (PSF) was applied to analyze the accuracy of CT-based clinical evaluations of lung nodule density. The PSF of the CT system was measured and used to perform the lung nodule image simulation. Then, the simulated image was resampled at intervals equal to the pixel size and the slice interval found in clinical high-resolution CT (HRCT) images. On those images, the nodule density was measured by placing a region of interest (ROI) commonly used for routine clinical practice, and comparing the measured value with the true value (a known density of object function used in the image simulation). It was quantitatively determined that the measured nodule density depended on the nodule diameter and the image reconstruction parameters (kernel and slice thickness). In addition, the measured density fluctuated, depending on the offset between the nodule center and the image voxel center. This fluctuation was reduced by decreasing the slice interval (i.e., with the use of overlapping reconstruction), leading to a stable density evaluation. Our proposed method of PSF-based image simulation accompanied with resampling enables a quantitative analysis of the accuracy of CT-based evaluations of lung nodule density. These results could potentially reveal clinical misreadings in diagnosis, and lead to more accurate and precise density evaluations. They would also be of value for determining the optimum scan and reconstruction parameters, such as image reconstruction kernels and slice thicknesses/intervals.

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  • Image filtering as an alternative to the application of a different reconstruction kernel in CT imaging: Feasibility study in lung cancer screening 査読

    Masaki Ohkubo, Shinichi Wada, Akihiro Kayugawa, Toru Matsumoto, Kohei Murao

    MEDICAL PHYSICS38 ( 7 ) 3915 - 3923   2011年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICS  

    Purpose: While the acquisition of projection data in a computed tomography (CT) scanner is generally carried out once, the projection data is often removed from the system, making further reconstruction with a different reconstruction filter impossible. The reconstruction kernel is one of the most important parameters. To have access to all the reconstructions, either prior reconstructions with multiple kernels must be performed or the projection data must be stored. Each of these requirements would increase the burden on data archiving. This study aimed to design an effective method to achieve similar image quality using an image filtering technique in the image space, instead of a reconstruction filter in the projection space for CT imaging. The authors evaluated the clinical feasibility of the proposed method in lung cancer screening.
    Methods: The proposed technique is essentially the same as common image filtering, which performs processing in the spatial-frequency domain with a filter function. However, the filter function was determined based on the quantitative analysis of the point spread functions (PSFs) measured in the system. The modulation transfer functions (MTFs) were derived from the PSFs, and the ratio of the MTFs was used as the filter function. Therefore, using an image reconstructed with a kernel, an image reconstructed with a different kernel was obtained by filtering, which used the ratio of the MTFs obtained for the two kernels. The performance of the method was evaluated by using routine clinical images obtained from CT screening for lung cancer in five subjects.
    Results: Filtered images for all combinations of three types of reconstruction kernels ("smooth," "standard," and "sharp" kernels) showed good agreement with original reconstructed images regarded as the gold standard. On the filtered images, abnormal shadows suspected as being lung cancers were identical to those on the reconstructed images. The standard deviations (SDs) for the difference between filtered images and reconstructed images ranged from 1.9 to 23.5 Hounsfield units for all kernel combinations; these SDs were much smaller than the noise SDs in the reconstructed images.
    Conclusions: The proposed method has good performance and is clinically feasible in lung cancer screening. This method can be applied to images reconstructed on any scanner by measuring the PSFs in each system. (C) 2011 American Association of Physicists in Medicine. [DOI:10.1118/1.3590363]

    DOI: 10.1118/1.3590363

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  • 3T MRIを用いた筋強直性ジストロフィー1型患者の大脳皮質・白質の非侵襲的評価

    高堂 裕平, 五十嵐 博中, 寺島 健史, 大久保 真樹, 下畑 享良, 岡本 浩一郎, 西澤 正豊, 中田 力

    新潟県医師会報728 ( 728 ) 7 - 8   2010年11月

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    記述言語:日本語   掲載種別:研究論文(その他学術会議資料等)   出版者・発行元:新潟県医師会  

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  • 肺結節体積評価のための濃度閾値設定に関する3次元CT画像シミュレーション解析 査読

    大野 健, 舟木 歩, 大久保真樹, 和田真一, 粥川啓廣, 松本 徹, 村尾晃平

    医学物理30 ( 2 ) 39 - 48   2010年11月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.11323/jjmp.30.2_39

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  • Gd-EOB-DTPA を用いた肝ダイナミックMRI の動脈優位相における画像アーチファクトに関するシミュレーション 査読

    深谷貴広, 内藤健一, 齋藤宏明, 瀧本宗徳, 粥川啓廣, 大久保真樹

    日本放射線技術学会雑誌66 ( 9 ) 1197 - 1203   2010年9月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.6009/jjrt.66.1197

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  • SSPを用いたCT画像の体軸方向空間分解能変換 査読

    粥川啓廣, 大久保真樹, 和田真一, 松本 徹, 村尾晃平, 山本眞司

    医学物理30 ( 1 ) 3 - 9   2010年8月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.11323/jjmp.30.1_3

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  • 低線量MDCT検診における画質と線量の最適化のための一考察 査読

    和田真一, 松本 徹, 西沢かな枝, 大久保真樹

    日本CT検診学会誌16 ( 3 ) 187 - 194   2009年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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  • Determination of point spread function in computed tomography accompanied with verification 査読

    Masaki Ohkubo, Shinichi Wada, Satoshi Ida, Masayuki Kunii, Akihiro Kayugawa, Toru Matsumoto, Kanae Nishizawa, Kohei Murao

    MEDICAL PHYSICS36 ( 6 ) 2089 - 2097   2009年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICS  

    A method for verifying the point spread function (PSF) measured by computed tomography has been previously reported [Med. Phys. 33, 2757-2764 (2006)]; however, this additional PSF verification following measurement is laborious. In the present study, the previously described verification method was expanded to PSF determination. First, an image was obtained by scanning a phantom. The image was then two-dimensionally deconvolved with the object function corresponding to the phantom structure, thus allowing the PSF to be obtained. Deconvolution is implemented simply by division of spatial frequencies (corresponding to inverse filtering), in which two parameters are used as adjustable ones. Second, an image was simulated by convolving the object function with the obtained PSF, and the simulated image was compared to the above-measured image of the phantom. The difference indicates the inaccuracy of the PSF obtained by deconvolution. As a criterion for evaluating the difference, the authors define the mean normalized standard deviation (SD) in the difference between simulated and measured images. The above two parameters for deconvolution can be adjusted by referring to the subsequent mean normalized SD (i.e., the PSF is determined so that the mean normalized SD is decreased). In this article, the parameters were varied in a fixed range with a constant increment to find the optimal parameter setting that minimizes the mean normalized SD. Using this method, PSF measurements were performed for various types of image reconstruction kernels (21 types) in four kinds of scanners. For the 16 types of kernels, the mean normalized SDs were less than 2.5%, indicating the accuracy of the determined PSFs. For the other five kernels, the mean normalized SDs ranged from 3.7% to 4.8%. This was because of a large amount of noise in the measured images, and the obtained PSFs would essentially be accurate. The method effectively determines the PSF, with an accompanying verification, after one scanning of a phantom.

    DOI: 10.1118/1.3123762

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  • Accurate determination of CT PSF with high precision 査読

    A. Kayugawa, S. Wada, M. Ohkubo, T. Matsumoto, K. Murao

    WORLD CONGRESS ON MEDICAL PHYSICS AND BIOMEDICAL ENGINEERING, VOL 25, PT 2 - DIAGNOSTIC IMAGING25 ( II ) 806 - 809   2009年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:SPRINGER  

    A method for verifying the point spread function (PSF) measured by computed tomography has been previously reported [1]. However, this additional PSF verification following measurement is laborious. In the present study, the previously described verification method was expanded to PSF determination [2], that is, the PSF determination and verification were performed concurrently by one scanning of the phantom. Using this method, PSF measurements were performed for 10 types of image reconstruction kernels in two kinds of scanners. As a result, accurate PSF determinations were achieved. Also, reproducibility for determining the PSF was investigated by using four slice images. Using each image, the PSF was determined by the proposed method. The MTFs were derived from the PSFs, and that variation was evaluated. The standard deviation (SD) of the MTFs was found to be small, suggesting the stability for determining the PSF. Our method was concluded to be accurate with high precision determining the CT PSF.

    DOI: 10.1007/978-3-642-03879-2_225

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  • Imaging of small spherical structures in CT: simulation study using measured point spread function 査読

    Masaki Ohkubo, Shinichi Wada, Masayuki Kunii, Toru Matsumoto, Kanae Nishizawa

    MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING46 ( 3 ) 273 - 282   2008年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER HEIDELBERG  

    Size and density measurements of objects undertaken using computed tomography (CT) are clinically significant for diagnosis. To evaluate the accuracy of these quantifications, we simulated three-dimensional (3D) CT image blurring; this involved the calculation of the convolution of the 3D object function with the measured 3D point spread function (PSF). We initially validated the simulation technique by performing a phantom experiment. Blurred computed images showed good 3D agreement with measured images of the phantom. We used this technique to compute the 3D blurred images from the object functions, in which functions are determined to have the shape of an ideal sphere of varying diameter and assume solitary pulmonary nodules with a uniform density. The accuracy of diameter and density measurements was determined. We conclude that the proposed simulation technique enables us to estimate the image blurring precisely of any 3D structure and to analyze clinical images quantitatively.

    DOI: 10.1007/s11517-007-0283-x

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  • MR用簡易ファントムを用いた磁化率強調画像(Susceptibility-weighted Imaging:SWI)の基礎的検討 査読

    太田絢子, 内藤健一, 大久保真樹, 猪又聖美, 大越幸和, 岡本浩一郎, 伊藤周子

    日本放射線技術学会雑誌63 ( 9 ) 1093 - 1098   2007年9月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.6009/jjrt.63.1093

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  • Identification of the anterior ethmoid arteries on thin-section axial images and coronal reformatted orbit images by means of multidetector row CT 査読

    N. Takahashi, M. Ohkubo, T. Higuchi, H. Maeda

    CLINICAL RADIOLOGY62 ( 4 ) 376 - 381   2007年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:W B SAUNDERS CO LTD  

    AIM: The aim of this study was to identify anterior ethmoid arteries on thin-section axial images and coronal reformatted images of the orbits using multidetector row computed tomography (CT).
    MATERIALS AND METHODS: One hundred and thirty-two patients underwent paranasal CT using a 16-row detector CT (n = 59) or a 6-row detector CT machine (n = 73) at 1 or 1.25 mm section width, respectively. Coronal images were reformatted at section widths of 3 and 1 mm. The anterior ethmoid arteries were identified for each patient. Differences were assessed using the chi-square test.
    RESULTS: All CT images were of approximately average diagnostic quality. Anterior ethmoid arteries were identified in 97.5 and 96.6% at section thicknesses of 1 and 1.25 mm on the axial images, respectively. There was no statistically significant difference in the detection rate (p=0.89). On the corona[ images, anterior ethmoid arteries were presented tangentially in 75.4 and 90.2% at section widths of 3 and 1 mm, respectively. The visibility of the anterior ethmoid arteries was rated significantly better on coronal images at a section width of 1 mm than on those at section widths of 3 mm (p < 0.001).
    CONCLUSION: Thin-section axial images and corona[ reformatted images using multi-detector row CT mostly depict anterior ethmoid arteries, and are useful to identify anterior ethmoid arteries for preoperative evaluation of paranasal sinuses. (c) 2006 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.crad.2006.11.010

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  • Increase in glutamate as a sensitive indicator of extracellular matrix integrity in peritumoral edema: a 3.0-tesla proton magnetic resonance spectroscopy study 査読

    Teruo Kimura, Masaki Ohkubo, Hironaka Igarashi, Ingrid L. Kwee, Tsutomu Nakada

    JOURNAL OF NEUROSURGERY106 ( 4 ) 609 - 613   2007年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER ASSOC NEUROLOGICAL SURGEONS  

    Object. The authors of previous studies based on diffusion tensor imaging have indicated that there are two types of peritumoral edema-namely, edema with preserved structural integrity of the glial matrix and edema with compromised glial matrix. The authors of this study hypothesized that functionality of the glutamate (Glu)-glutamine shuttle, a vital neuron-glia interaction, may be differentially affected by peritumoral edema. They tested this hypothesis using proton magnetic resonance (MR) spectroscopy on a 3.0-tesla system that is capable of quantifying Glu without need of editing.
    Methods. Twenty-three patients, each with a single brain tumor mass and peritumoral edema (nine high-grade gliomas, eight metastatic brain tumors, and six meningiomas), and nine healthy individuals participated in this study. Single-voxel proton MR imaging targeting the region of peritumoral edema was performed using a 3.0-tesla system.
    Glutamate levels in the peritumoral edema of nonglial tumors was significantly elevated (p < 0.01) compared with edema associated with glial tumors or normal white matter. The finding confirmed that peritumoral edema in nonglial tumors is distinct from that of glial tumors, as previously indicated in diffusion tensor imaging studies. The authors hypothesized that the former condition represents a compensatory increase in activities of the Glu-glutamine shuttle brought about by simple expansion of the extracellular space due to edema.
    Conclusions. The assessment of Glu concentrations in peritumoral edema using 3.0-tesla proton MR spectroscopy may be developed into an objective index of the structural integrity of the glial matrix.

    DOI: 10.3171/jns.2007.106.4.609

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  • 脳血流PET 検査における15O-H2O投与量の違いに対する画像の評価

    山野井理恵, 河村和紀, 岡本浩一郎, 大久保真樹

    新潟核医学懇話会記録集35   22 - 26   2007年4月

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    記述言語:日本語   掲載種別:研究論文(研究会,シンポジウム資料等)  

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  • The CT image standardization based on the verified PSF. 査読

    Shinichi Wada, Masaki Ohkubo, Masayuki Kunii, Toru Matsumoto, Kohei Murao, Kazuo Awai, Mitsuru Ikeda

    MEDICAL IMAGING 2007: PHYSICS OF MEDICAL IMAGING, PTS 1-36510 ( 65104D ) 1 - 8   2007年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:SPIE-INT SOC OPTICAL ENGINEERING  

    This study discusses a method of CT image quality standardization that uses a point-spread function (PSF) in MDCT. CT image I(x,y,z) is represented by the following formula: I(x,y,z) = O(x,y,z)***PSF(x,y,z). Standardization was performed by measuring the three-dimensional (3-D) PSFs of two CT images with different image qualities. The image conversion method was constructed and tested using the 3-D PSFs and CT images of the CT scanners of three different manufacturers. The CT scanners used were Lightspeed QX/i, Somatom Volume Zoom, and Brilliance-40. To obtain the PSF(x,y) of these CT scanners, the line spread functions of the respective reconstruction kernels were measured using a phantom described by J.M. Boone. The kernels for each scanner were: soft, standard, lung, bone, and bone plus (GE); B20f, B40f, B41f, B50f, and B60f (Siemens); and B, C, D, E, and L (Philips). Slice sensitivity profile (SSP) were measured using a micro-disk phantom (50 mu m* phi 1 mm) with 5 mm slice thickness and beam pitch of 1.5 (GE, Siemens) and 0.626 (Philips). 3-D PSF was verified using an MDCT QA phantom. Real chest CT images were converted to images with contrasting standard image quality. Comparison between the converted CT image and the original standard image showed good agreement. The usefulness of the image conversion method is discussed using clinical CT images acquired by CT scanners produced by different manufacturers.

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  • An effective method to verify line and point spread functions measured in computed tomography 査読

    Masaki Ohkubo, Sinichi Wada, Toru Matsumoto, Kanae Nishizawa

    MEDICAL PHYSICS33 ( 8 ) 2757 - 2764   2006年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICS  

    This study describes an effective method for verifying line spread function (LSF) and point spread function (PSF) measured in computed tomography (CT). The CT image of an assumed object function is known to be calculable using LSF or PSF based on a model for the spatial resolution in a linear imaging system. Therefore, the validities of LSF and PSF would be confirmed by comparing the computed images with the images obtained by scanning phantoms corresponding to the object function. Differences between computed and measured images will depend on the accuracy of the LSF and PSF used in the calculations. First, we measured LSF in our scanner, and derived the two-dimensional PSF in the scan plane from the LSF. Second, we scanned the phantom including uniform cylindrical objects parallel to the long axis of a patient's body (z direction). Measured images of such a phantom were characterized according to the spatial resolution in the scan plane, and did not depend on the spatial resolution in the z direction. Third, images were calculated by two-dimensionally convolving the true object as a function of space with the PSF. As a result of comparing computed images with measured ones, good agreement was found and was demonstrated by image subtraction. As a criterion for evaluating quantitatively the overall differences of images, we defined the normalized standard deviation (SD) in the differences between computed and measured images. These normalized SDs were less than 5.0% (ranging from 1.3% to 4.8%) for three types of image reconstruction kernels and for various diameters of cylindrical objects, indicating the high accuracy of PSF and LSF that resulted in successful measurements. Further, we also obtained another LSF utilizing an inappropriate manner, and calculated the images as above. This time, the computed images did not agree with the measured ones. The normalized SDs were 6.0% or more (ranging from 6.0% to 13.8%), indicating the inaccuracy of the PSF and LSF. We could verify LSFs and PSFs for three types of reconstruction kernels, and demonstrated differences between modulation transfer functions (MTFs) derived from validated LSFs and inaccurate LSFs. Our technique requires a simple phantom that is suitable for clinical scanning, and does not require a particular phantom containing some metals or specific fine structures, as required in methods previously used for measurements of spatial resolution. Therefore, the scanned image of the phantom will be reliable and of good quality, and this is used directly as a confident reference image for the verification. When one obtains LSF, PSF or MTF values, verification using our method is recommended. Further, when another method for the measurement of LSF and PSF is developed, it could be validated using our technique, as illustrated in the method proposed by Boone [Med. Phys. 28, 356-360 (2001)] and used in this paper. (C) 2006 American Association of Physicists in Medicine.

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  • Parietal white matter abnormalities in obsessive-compulsive disorder: a magnetic resonance spectroscopy study at 3-Tesla 査読

    H. Kitamura, T. Shioiri, T. Kimura, M. Ohkubo, T. Nakada, T. Someya

    ACTA PSYCHIATRICA SCANDINAVICA114 ( 2 ) 101 - 108   2006年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:BLACKWELL PUBLISHING  

    Objective: To identify a neurochemical basis for the hypothesis that an aberrant cortico-subcortical circuit underlies obsessive-compulsive disorder (OCD). The white matter was also investigated because of recent research which suggests the altered connectivity of axons.
    Method: Using 3-Tesla magnetic resonance spectroscopy, the relative concentrations of N-acetylaspartate (NAA) and choline-containing compounds (Cho) to creatine/phosphocreatine (Cr) were measured in the anterior cingulate, basal ganglia, thalamus, frontal and parietal white matter of 12 OCD patients, and 32 control subjects.
    Results: The mean concentration of Cho/Cr was significantly higher in the patients than in the controls, but only in the parietal white matter, while no significant group differences in NAA/Cr were observed in any of the brain regions. Parietal Cho/Cr correlated positively with the severity of OCD symptoms.
    Conclusion: This finding provides indirect evidence for the parietal white matter involvement in OCD, thus suggesting a change in the phospholipids of myelinated axons and/or glia cells.

    DOI: 10.1111/j.1600-0447.2006.00858.x

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  • CT画像系において測定された line spread function (PSF) および point spread function (PSF) の精度評価法に関する研究 査読

    國井正之, 和田真一, 大久保真樹, 原田正紘, 西澤かな枝, 松本 徹

    医学物理26 ( 2 ) 57 - 64   2006年6月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.11323/jjmp2000.26.2_57

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  • A method of accuracy evaluation of line spread function (LSF) and point spread function (PSF) measured in computed tomography. 査読

    Shinichi Wada, Masaki Ohkubo, Toru Matsumoto, Kanae Nishizawa

    MEDICAL IMAGING 2006: PHYSICS OF MEDICAL IMAGING, PTS 1-36142   61423I-1 - 61423I-8   2006年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:SPIE-INT SOC OPTICAL ENGINEERING  

    This study describes a method of accuracy evaluation of verifying the line spread function (LSF) and point spread function (PSF) measured in computed tomography (CT). The CT image of an assumed object-function was calculated using LSF or PSF based on a model to understand spatial resolution in the imaging system. Validities of LSF and PSF were confirmed by comparing the calculated image with the scanned image of the phantom corresponding to the object-function. Differences between the scanned and calculated images depended on accuracies of LSF and PSF used in the calculations. First, we measured LSF in a scanner, and derived the two-dimensional PSF in the scan-plane from LSF. Second, we scanned the phantom including uniform cylindrical objects parallel to the long axis of a patient's body (z-direction). Scanned images of such a phantom were characterized according to spatial resolution in the scan-plane, and didn't depend on spatial resolution in the z-direction. Third, images were calculated by two-dimensionally convolving the object-function with PSF, which object-function was determined to correspond to the phantom. Calculated images agreed with scanned images, confirming validities of PSF and LSF. On the other hand, we obtained another LSF with an inappropriate manner, and calculated images as mentioned above. On this case, the calculated images did not agree with the scanned images, indicating the inaccuracy of LSF. We could verify LSFs and PSFs for three types of reconstruction kernels. When one obtains LSF, PSF or MTF, verification using the proposed method is recommended.

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  • 肝臓 ダイナミック MRI における 3D-VIBE法 の至適フリップ角の検討 査読

    内藤健一, 大越幸和, 大久保真樹, 八木下裕子, 岡 純子, 太田絢子, 山本哲史, 駒澤絵美

    日本放射線技術学会雑誌61 ( 10 ) 1441 - 1446   2005年10月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.6009/jjrt.KJ00004039788

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  • Validation of the blurring of a small object on CT images calculated on the basis of three-dimensional spatial resolution 査読

    Ohkubo M, Wada S, Saito M

    Igaku Butsuri25 ( 3 ) 132 - 140   2005年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.11323/jjmp2000.25.3_132

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  • High-resolution magnetic resonance of the extracranial facial nerve and parotid duct: demonstration of the branches of the intraparotid facial nerve and its relation to parotid tumours by MRI with a surface coil 査読

    N Takahashi, K Okamoto, M Ohkubo, M Kawana

    CLINICAL RADIOLOGY60 ( 3 ) 349 - 354   2005年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:W B SAUNDERS CO LTD  

    AIM: To investigate the usefulness of high-resolution MR imaging in the evaluation of the extracranial. facial nerve, compared with surgical findings.
    MATERIALS AND METHODS: Thirteen patients with benign parotid tumours were studied on a 1.5-T MR system with a 3 in circular surface coil. High-resolution T1-weighted spin-echo, T2-weighted fast spin-echo, and three-dimensional gradient-recalled acquisition in the steady state (GRASS) images were obtained in the axial planes. Oblique reformatted images were generated. Tumours, parotid ducts and facial nerves were identified on these images. The relationship of the tumours to the facial nerves was confirmed at surgery.
    RESULTS: Facial nerves appeared as linear structures of low intensity on all pulse sequences. The main trunks and cervicofacial and temporofacial divisions of the facial nerves were identified in 100%, 84.1% and 53.8% of GRASS images, respectively. Parotid ducts appeared as structures of low intensity on T1-weighted (66.6%) and GRASS images (81.8%), and as structures of very high intensity on T2-weighted images (91.7%). The relationships of the tumours to the facial nerves were correctly diagnosed in 11 (91.7%) of 12 cases.
    CONCLUSION: High-resolution MR imaging depicts the extracranial facial nerve and the parotid duct, and is useful for preoperative evaluation of parotid gland tumours. (C) 2005 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.crad.2004.06.018

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  • Endorectal Coil の特性評価 MRS での使用を目的とした検討

    八木下裕子, 内藤健一, 太田絢子, 岡 純子, 大越幸和, 大久保真樹

    日本放射線技術学会東北部会雑誌14   149 - 151   2005年1月

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  • 肝臓 dynamic MRI における 3D VIBE の有用性

    内藤健一, 八木下裕子, 岡 純子, 太田絢子, 大越幸和, 大久保真樹

    日本放射線技術学会東北部会雑誌14   139 - 141   2005年1月

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  • Measurements and precisions of point spread function of multi-slice CT 査読

    S Wada, M Ohkubo, T Matsumoto

    Medical Imaging 2005: Physics of Medical Imaging, Pts 1 and 25745 ( 22 ) 1209 - 1216   2005年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:SPIE-INT SOC OPTICAL ENGINEERING  

    The determination of point spread function (PSF) is essential for the assessment of the performance of multi-slice CT corresponding to particular scanning or reconstruction condition. We studied the accuracy of the method for determination of PSF. The precision were evaluated with use of special made phantom and computer simulations. The PSF of some kinds of multi-slice CT were evaluated under the several scanning or reconstruction conditions. The performances were compared with each other and discussed. The PSF (x, y, z) was measured with separate components of PSF (x, y)) and LSF(z). In the measurement of PSF(x, y) and LSF(z), we used Boone phantom and delta phantom respectively. The PSF(x,y) was calculated from LSF(x) and LSF(y). The LSF(z) obtained from delta phantom was added for the calculation of PSF(x,y,z) with use of the following formula..
    PSF(x, y, z) = PSF(x, y) (.) LSF(Z) = LSF(x) (.) LSF(y) (.) LSF(z)
    The precision for the obtained LSF and PSF were evaluated by phantom experiment with computer simulation using following equations.
    I (x) = LSF(x) * O(x)
    I(x, y, z) = integral(infinity)(-infinity)integral(infinity)(-infinity)integral O-infinity(-infinity)(x, y, z) (.) PSF(x - x', y - y', z - z') dx dy dz
    The precision of the measured PSF(x, y) was evaluated to be a good approximation for the image of the blood-vessel phantom. The results propose the method for the evaluation of the precision of measured point spread function.. At the same time this results suggests the method of the calculation of the CT image affected by spatial resolution.

    DOI: 10.1117/12.596683

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  • CT画像系におけるline spread function(LSF)およびslice sensitivity profile(SSP)とpoint spread function(PSF)の関連 査読

    大久保真樹, 和田真一, 小林悌二, 李 鎔範, 蔡 篤儀

    医学物理24 ( 3 ) 115 - 122   2004年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.11323/jjmp2000.24.3_115

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  • Medical image classification using genetic-algorithm based fuzzy-logic approach 査読

    DY Tsai, Y Lee, M Sekiya, M Ohkubo

    JOURNAL OF ELECTRONIC IMAGING13 ( 4 ) 780 - 788   2004年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:I S & T - SOC IMAGING SCIENCE TECHNOLOGY  

    In this paper we present a genetic-algorithm-based fuzzy-logic approach for computer-aided diagnosis scheme in medical imaging. The scheme is applied to discriminate myocardial heart disease from echocardiographic images and to detect and classify clustered microcalcifications from mammograms. Unlike the conventional types of membership functions such as trapezoid, triangle, S curve, and singleton used in fuzzy reasoning, Gaussian-distributed fuzzy membership functions (GDMFs) are employed in the present study. The GDMFs are initially generated using various texture-based features obtained from reference images. Subsequently the shapes of GDMFs are optimized by a genetic-algorithm learning process. After optimization, the classifier is used for disease discrimination. The results of our experiments are very promising. We achieve an average accuracy of 96% for myocardial heart disease and accuracy of 88.5% at 100% sensitivity level for micro-calcification on mammograms. The results demonstrated that our proposed genetic-algorithm-based fuzzy-logic approach is an effective method for computer-aided diagnosis in disease classification. 2004, SPIE and IST.

    DOI: 10.1117/1.1786607

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  • CT angiographyの血管描出能とpoint spread functionの関係 査読

    和田真一, 大久保真樹, 田中 孝, 吉村宣彦, 笹井啓資, 松本 徹

    胸部CT検診10 ( 2 ) 200 - 209   2004年4月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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  • spiral SPGR法の基礎的検討

    八木下裕子, 大越幸和, 内藤健一, 柴木充朗, 大久保真樹

    日本放射線技術学会東北部会雑誌13   112 - 115   2004年1月

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  • Elliptical Centric法を用いた造影三次元MR Angiographyにおける造影効果持続時間および撮像タイミングに関する検討 査読

    八木下裕子, 大越幸和, 大久保真樹, 内藤健一, 井上智子, 蔡 篤儀

    日本放射線技術学会雑誌59 ( 12 ) 1555 - 1560   2003年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.6009/jjrt.KJ00000921687

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  • Fast RecoveryパルスによるFast Spin Echo画像の信号強度の増加に関する検討 査読

    大久保真樹, 大越幸和, 内藤 健一, 八木下裕子, 蔡 篤儀

    日本放射線技術学会雑誌59 ( 7 ) 879 - 882   2003年7月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.6009/jjrt.KJ00003174218

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  • An integrated fuzzy-GA-based CAD system for disease discriminations 査読

    Tsai D-Y, Lee Y, Sekiya M, Ohkubo M, Kojima K, Yamada I

    Proceedings of the IASTED International Conference on BIOMEDICAL ENGINEERING   166 - 171   2003年6月

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    記述言語:英語   掲載種別:研究論文(その他学術会議資料等)  

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  • 3D FIESTA法の基礎的検討

    内藤健一, 大越幸和, 八木下裕子, 柴木充朗, 大久保真樹

    日本放射線技術学会東北部会雑誌12   124 - 127   2003年1月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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  • 造影三次元MR angiography における撮像タイミングに関するシミュレーション 査読

    大久保真樹, 大越幸和, 井上智子, 内藤健一, 八木下裕子, 蔡 篤儀

    日本放射線技術学会雑誌58 ( 5 ) 705 - 710   2002年5月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.6009/jjrt.KJ00001364431

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  • Evaluation of efficacy of an automated single-voxel proton MRS algorithm on a 3T system 査読

    Masaki Ohkubo, Teruo Kimura, Hitoshi Matsuzawa, Tsuyoshi Matsuda, Ingrid L. Kwee, Tsutomu Nakada

    Magnetic Resonance in Medical Sciences1 ( 2 ) 121 - 124   2002年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Purpose: To evaluate the efficacy of a fully automatic, single-voxel, proton MR spectroscopy algorithm on a 3.0T MR system. Methods: The PROBE/SVQ algorithm (GE Medical Systems) was evaluated on a General Electric (GE) Signa LX-3T system. Ten normal volunteers (female, 21.1±2.0 years old) participated in the study. Nine representative regions of interest were examined, namely, right and left frontal white matter
    right and left parietal white matter
    right and left basal ganglia
    right and left dentate nucleus
    and pons. Results: The mean coefficients of variation in all regions for the N-acetyl-aspartate to creatine ratio (NAA/Cr), choline to creatine ratio (Cho/Cr), and choline to N-acetyl-aspartate ratio (Cho/NAA) were 10.2±2.4%, 11.4±3.2% and 12.6±1.4%, respectively. Conclusion: A fully automated spectroscopic examination under clinical setting utilizing the PROBE/SVQ algorithm appears to be a reliable method, extending the window of routine clinical assessment of brain metabolism. © 2002 by Japanese Society for Magnetic Resonance in Medicine.

    DOI: 10.2463/mrms.1.121

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  • GE社製MRI装置Signaの頭頚部用Neurovascular Array Coilの評価 査読

    内藤健一, 大越幸和, 井上智子, 大久保真樹, 八木下裕子

    新大医保紀要7 ( 3 ) 357 - 361   2001年12月

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  • 造影三次元 MR angiography における造影効果の持続時間に関するシミュレーション 査読

    大久保 真樹, 大越 幸和, 井上 智子, 内藤 健一, 鈴木 清隆

    日本磁気共鳴医学会雑誌21 ( 5 ) 186 - 192   2001年7月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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  • A Morphology-Based Method for Automated Detection of Clustered Microcalcifications 査読

    Tsai D-Y, Sekiya M, Lee Y, Yamazaki Y, Ohkubo M, Kojima K, Yamaada I

    Proceedings of the IASTED International Conference SIGNAL PROCESSING, PATTERN RECOGNITION & APPLICATIONS   159 - 162   2001年7月

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)  

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  • 造影3次元MR angiographyに関する基礎的検討ー造影効果持続時間および撮像のタイミングについてー 査読

    井上智子, 大越幸和, 大久保真樹, 内藤健一

    新大医保紀要7 ( 2 ) 265 - 270   2000年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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  • 超高磁場MR装置を用いたプロトンスペクトロスコピーに関する基礎研究 招待 査読

    大久保真樹, 中田 力, 松沢 等, 松田 豪

    INNERVISION15 ( 8 ) 66   2000年8月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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  • 超高磁場MRI装置による顎関節画像撮影の初期検討 査読

    山川智子, 大久保真樹, 羽柴正夫, 中田 力, 伊藤壽助

    日磁医誌20 ( 2 ) 80 - 92   2000年4月

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  • A comparative study of simple methods to quantify cerebral blood flow with acetazolamide challenge by using iodine-123-IMP SPECT with one-point arterial sampling 査読

    M Ohkubo, Odano, I

    ANNALS OF NUCLEAR MEDICINE14 ( 2 ) 115 - 120   2000年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:JAPANESE SOCIETY NUCLEAR MEDICINE  

    The aim of this study was to compare the accuracy of simplified methods for quantifying rCBF with acetazolamide challenge by using I-123-N-isopropyl-p-iodoamphetamine (IMP) and SPECT with one-point arterial sampling. After acetazolamide administration we quantified rCBF in 12 subjects by the following three methods: (a) the modified microsphere method, (b) the IMP-autoradiographic (ARG) method based on a two-compartment one-parameter model, and (c) the simplified method based on a two-compartment two-parameter model (functional IMP method). The accuracy of these methods was validated by comparing rCBF values with those obtained by the standard method: the super-early microsphere method with continuous withdrawal of arterial blood. On analyzing rCBF in each flow range (0-0.25, 0.25-0.5, 0.5-0.75 and more than 0.75 ml/g/min), rCBF values obtained by both methods (a) and (c) showed significant correlations (p < 0.01) with those obtained by the standard method in every range, but rCBF values obtained by method (b) did not significantly correlated in the high flow range (0.5-0.75 and more than 0.75 ml/g/min). Method (c) was found to be the most accurate, even though it needs two serial SPECT scans. When requiring one SPECT scan, method (a) was considered to be superior to method (b) because of its accuracy, especially in high flow regions loaded with acetazolamide.

    DOI: 10.1007/BF02988590

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  • Noninvasive quantification of cerebral blood flow using Tc-99m-ECD and SPECT 査読

    Odano, I, M Ohkubo, T Yokoi

    JOURNAL OF NUCLEAR MEDICINE40 ( 10 ) 1737 - 1744   1999年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SOC NUCLEAR MEDICINE INC  

    The aim of this study was to develop a simple, noninvasive method for quantifying regional cerebral blood flow (rCBF) using Tc-99m-ethyl cysteinate dimer (ECD) by a single SPECT scan and single venous sampling. Methods: Using a three-compartment model, we introduced the regional brain fractionation index (BF!); Cb(T-s)/integral(0)(Ts) Ca(tau)d tau[Ca(t), arterial input; Cb(t), brain activity]. Regional BFI obtained at the optimum time T-s (min) was converted to rCBF using an exponential function, which was obtained by analyzing the relationship between regional BFI and rCBF (= F) obtained by the standard Xe-133 inhalation SPECT method. The integral of the concentration of Tc-99m-ECD in arterial blood corrected for physical decay [Ca(t)] in BFI was estimated from a single venous blood sample obtained at the optimum time T-v using the regression line obtained by analyzing the relationship between the integral of Ca(t) and venous sample data. The data come from three groups of patients. The first group of patients (n = 16) underwent a complete Tc-99m-ECD BFI study with measurement of Ca(t) and dynamic SPECT scanning, as well as a Xe-133 inhalation study to measure rCBF. The results were used to analyze the relationship between regional BFI and rCBF (obtained with Xe-133) and to determine the optimum time T-s for obtaining BFI. Data from the second group of patients (n = 15) were used to analyze the relationship between the integral of Ga(t) and venous sample data and to determine the optimum time T-v for one-point Venous blood sampling. Finally, the third group of patients (8 patients, 10 studies) was used to validate the current method by comparing the results with Xe-133 inhalation SPECT. Results: Regional BFI obtained at time T-s = 20 min showed good agreement (r = 0.907; a = 0.552, b = 0.962) with rCBF. The venous sample data obtained at time T-v = 6 min showed a good correlation (r = 0.988) with BFI. In comparing rCBF Values thus obtained and those obtained by the Xe-133 method, we found a good correlation (r = 0.917, slope = 1.01). Conclusion: The proposed method has three advantages: (a) accurate quantification of rCBF without underestimation in the high flow range, (b) simplicity and noninvasiveness and (c) the ability to use any type of SPECT camera for the study.

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  • Quantification of cerebral blood flow using technetium-99m ethyl cysteinate dimer and single-photon emission tomography 査読

    Odano, I, M Ohkubo

    EUROPEAN JOURNAL OF NUCLEAR MEDICINE26 ( 3 ) 246 - 252   1999年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER VERLAG  

    The aim of this study was to develop a new method for quantifying regional cerebral blood flow (rCBF) with technetium-99m ethyl cysteinate dimer (ECD) and single-photon emission tomography (SPET). Employing a three-compartment model, we introduced a parameter, regional brain fractionation index (BFI), that reflects rCBF values and is obtained by a single SPET scan at optimum time T (min) after tracer injection and the integral of arterial input. By analysing the dynamic SPET and arterial blood sampling data of 15 subjects, including the results of acetazolamide challenges, with the graphical plot method, optimum time T was determined to be approximately 20 min post injection. Regional BFI values of each subject were calculated from the single SPET data at 20 min and arterial input. The relationship between the values of regional BFI and rCBF obtained by xenon-133 inhalation SPET was analysed by approximation with an exponential function, resulting in good agreement (r = 0.907). In the present method, I CBF values were determined from regional BFI values by using the inverse exponential function as a non-linear regression curve. To validate the method, we applied it to six other subjects, in whom acetazolamide challenges were also performed. In comparing rCBF values thus obtained and those obtained by Xe-133 inhalation SPET, we found a good correlation (r = 0.901) with an inclination approximating 1 (= 1.02) and without underestimation of rCBF in the high-flow range. Since the present method does not require dynamic planar imaging or dynamic SPET scanning, it can be applied to any type of SPET scanner and is useful in clinical SPET studies.

    DOI: 10.1007/s002590050384

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  • Diamox負荷時における123I-IMP SPECTを用いたマイクロスフェアモデルに基づく局所脳血流量定量法の精度の検討 査読

    大久保真樹, 小田野行男, 野口栄吉, 大滝広雄, 柴木充朗, 土橋幸夫, 横井孝司

    核医学35 ( 3 ) 147 - 151   1998年3月

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  • 分割投与99mTc-ECD SPECTと静脈採血によるDiamox負荷前後の脳血流測定法 査読

    小田野行男, 大久保真樹, 野口栄吉, 大滝広雄, 柴木充朗, 土橋幸夫

    核医学35 ( 2 ) 74 - 75   1998年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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  • 99mTc-ECD SPECTを用いた3-コンパートメントモデルに基づく脳血流測定法 査読

    小田野行男, 大久保真樹, 野口栄吉, 大滝広雄, 柴木充朗, 土橋幸夫

    核医学35 ( 8 ) 702 - 703   1998年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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  • 細胞動態からみた薬剤併用放射線照射における細胞致死効果 査読

    藤田勝三, 大久保真樹, 日向浩, 酒井邦夫, 伊藤猛, 末山博男

    関越UFT研究会10   7 - 10   1997年12月

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  • FM3A細胞における5-FU+CDDPの放射線増感効果の細胞動態学的検討 査読

    藤田勝三, 大久保真樹, 日向 浩, 酒井邦夫

    新大医短紀要6 ( 2 ) 229 - 232   1997年12月

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  • 99mTc-ECD SPECTを用いたマイクロスフェアーモデルに基づく非侵襲的な脳血流測定1点動脈または静脈 採血法 査読

    小田野行男, 大久保真樹, 野口栄吉, 大滝広雄, 柴木充朗, 土橋幸夫

    核医学34 ( 12 ) 1111 - 1117   1997年12月

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  • I-123 IMP SPECTによる簡便なrCBF定量測定法の臨床応用, 招待 査読

    大久保真樹, 小田野行男, 野口栄吉, 大滝広雄, 柴木充朗, 土橋幸夫

    映像情報メディカル29 ( 22 ) 1330 - 1333   1997年11月

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  • Quantification of cerebral blood flow and partition coefficient using iodine-123-iodoamphetamine 査読

    Odano, I, M Ohkubo, M Takahashi

    JOURNAL OF NUCLEAR MEDICINE38 ( 8 ) 1248 - 1253   1997年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SOC NUCLEAR MEDICINE INC  

    The aim of this study was to develop a simple, noninvasive method for quantifying both regional cerebral blood flow (rCBF) and the partition coefficient (lambda) using N-isopropyl-p-[I-123]iodoamphetamine and SPECT. Methods: By employing a two-compartment model (influx, K-1; outflux, k(2)), a new method was introduced that requires two serial SPECT scans at 30 min and 60 min, and a single arterial sample 5 min after tracer injection. The integral of the arterial input function is inferred from the sample by using the correlation obtained from 25 subjects. Two original mathematical functions, Phi for K-1 and Gamma for h (= K-1/k(2)), were obtained from the input functions of 12 subjects. The values of K-1 and lambda are determined from the two scans and the single arterial sample by using these functions. The values obtained for K-1 (= rCBF) and lambda weve compared with those obtained by nonlinear least-squares fitting analysis and the Xe-133 inhalation SPECT method, Results: K-1 and lambda were in good agreement with the values obtained by nonlinear least-squares fitting analysis (r = 0.873 in K-1 and r = 0.825 in lambda), and rCBF values were closely correlated with those obtained by the Xe-133 method (r = 0.843). Conclusion: The proposed method has three advantages: (a) accurate, simultaneous quantification of both rCBF and the partition coefficient; (b) simplicity and noninvasiveness; and (c) a relatively short period (approximately 70 min) for the study.

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  • A comparative study of simple methods to measure regional cerebral blood flow using iodine-123-IMP SPECT 査読

    M Ohkubo, Odano, I, M Takahashi

    JOURNAL OF NUCLEAR MEDICINE38 ( 4 ) 597 - 601   1997年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SOC NUCLEAR MEDICINE INC  

    The aim of this study was to compare the accuracy and reliability of simple methods of quantifying regional cerebral blood Row (rCBF) with I-123-labeled N-isopropyl-p-iodoamphetamine (IMP) and SPECT and to determine which method was best. Methods: Four methods were examined: (a) the microsphere method with continuous withdrawal of arterial blood, which was based on a microsphere model using the SPECT image obtained 5 min after tracer injection, (b) the microsphere method with one-point sampling, which was the same as the first method except that one-point sampling was used instead of continuous withdrawal, (c) the modified microsphere method with one-point sampling, which was the same as the second method except that a later SPECT image (30-min postinjection) with correction was used and (d) a table look-up method based on a two-compartment model with one-point arterial blood sampling and two SPECT scans obtained 40- and 180-min postinjection. The accuracy of these methods was validated by comparing the rCBF values with those obtained by nonlinear least squares fitting analysis based on the two-compartment model in 15 subjects. Results: Regional cerebral blood flow values obtained by the first method correlated most closely with those obtained by nonlinear least squares fitting analysis (error, 6.8%). The second method estimated rCBF with a mean error of 10.4%. The third method estimated rCBF with a mean error of 13.1%, even though it tended to slightly overestimate rCBF. The fourth method was inclined to underestimate rCBF with a mean error of 17.1%, and it greatly overestimated regional distribution volume. Conclusion: The first method was the most accurate and reliable. For less invasiveness, the first method should be combined with one-point sampling instead of continuous withdrawal, which was used in the second method. When using a delayed SPECT image with a conventional SPECT scanner, the third method was considered to be superior to the fourth method.

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  • FM3A細胞に対する5-FU+CDDPの放射線増感効果-細胞増殖と色素排除能による解析- 査読

    藤田勝三, 酒井邦夫, 樋口正一, 末山博男, 大久保真樹

    新潟大学医療技術短期大学部紀要6 ( 1 ) 103 - 108   1997年2月

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    記述言語:日本語   掲載種別:研究論文(大学,研究機関等紀要)  

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  • 学生用計測機器操作支援システム 査読

    中村久吾, 大久保真樹

    新潟大学医療技術短期大学部紀要6 ( 1 ) 123 - 128   1997年2月

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    記述言語:日本語   掲載種別:研究論文(大学,研究機関等紀要)  

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  • 123I-IMP,99mTc-HMPAOおよび99mTc-ECDによる脳血流SPECT画像の比較検討 査読

    小田野行男, 大久保真樹, 高橋 誠, 野口栄吉, 大滝広雄, 笠原敏文, 柴木充朗, 羽田野政義

    核医学34 ( 3 ) 189 - 194   1997年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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  • 99mTc-ECD SPECTにおける2分割投与法(split-dose法)の問題点と改良法 査読

    小田野行男, 大久保真樹, 高橋 誠, 野口栄吉, 大滝広雄, 柴木充朗, 笠原敏文, 羽田野政義

    核医学34 ( 5 ) 323 - 328   1997年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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  • 125I-iomazenil binding shows stress- and/or diazepam-induced reductions in mouse brain: Supporting data for 123I-iomazenil SPECT study of anxiety disorders 査読

    Makoto Takahashi, Ikuo Odano, Shozo Fujita, Masaki Ohkubo

    Annals of Nuclear Medicine11 ( 3 ) 243 - 250   1997年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Springer Tokyo  

    Effects of repeated swim stress on the binding of 125I-iomazenil were examined in the brains of diazepam-treated and non-treated mice. The mice were orally administered diazepam or vehicle (0.5% ethylene glycol) and subjected to daily swim stress (at 20°C for 10 min) for seven consecutive days. The distribution and the amount of 125I-iomazenil binding were analyzed autoradiographically after in vivo and in vitro binding experiments. Repeated swim stress decreased the in vivo binding in the hippocampus (p &lt
    0.05) and cerebral cortex (p &lt
    0.05) of vehicle-treated mice but caused no significant changes in diazepam-treated mice. Subchronic treatment with diazepam decreased the in vivo binding approximately 50% in all brain regions examined (p &lt
    0.01). The in vitro experiment, however, revealed no significant changes except in the hippocampus, where a small but significant decrease in the binding was observed after subchronic treatment with diazepam (p &lt
    0.01). The stress- or diazepam-induced reductions seem to represent alterations in the in vivo environment related to 125I-iomazenil binding. These results suggest that we can investigate the pathophysiology of stress and anxiety with 123I-iomazenil SPECT. Care must be taken concerning the effects of benzodiazepines.

    DOI: 10.1007/BF03164770

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  • FM-3A細胞に対する5-FU+CDDPの放射線増感効果

    藤田勝三, 樋口正一, 末山博男, 酒井邦夫, 大久保真樹

    関越UFT研究会9   21 - 24   1996年12月

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  • Elevation of cerebral lactate detected by localized H-1-magnetic resonance spectroscopy in migraine during the interictal period 査読

    H Wantanabe, T Kuwabara, M Ohkubo, S Tsuji, T Yuasa

    NEUROLOGY47 ( 4 ) 1093 - 1095   1996年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:LITTLE BROWN CO  

    We used localized H-1-magnetic resonance spectroscopy (MRS) to study the metabolic changes in the brains of patients with migraine during the interictal period. Measurement of metabolite levels in the occipital visual cortex in six normal subjects and six patients disclosed high lactate levels in the five patients who had experienced a migraine attack within the previous 2 months. One patient who had not experienced a migraine attack in the previous 4 years did not show a lactate peak. We speculate that anaerobic glycolysis occurs in the brains of patients with migraine during the interictal period, and a long attack-free period may normalize the subclinical metabolic disturbance.

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  • Radiosensitization of FM3A cells by 5-fluorouracil plus cisplatin 査読

    Higuchi S, Fujita S, Sueyama H, Ohkubo M, Sakai K

    Acta Medica et Biologica44 ( 3 ) 141 - 145   1996年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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    その他リンク: http://dspace.lib.niigata-u.ac.jp/dspace/handle/10191/33172

  • I-123 IMPによる新しい脳機能定量法 査読

    大久保真樹, 小田野行男, 高橋 誠 他

    映像情報メディカル28 ( 18 ) 1079 - 1083   1996年9月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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  • A multicenter validation of regional cerebral blood flow quantitation using [I-123]iodoamphetamine and single photon emission computed tomography 査読

    H Iida, T Akutsu, K Endo, H Fukuda, T Inoue, H Ito, S Koga, A Komatani, Y Kuwabara, T Momose, S Nishizawa, Odano, I, M Ohkubo, Y Sasaki, H Suzuki, B Tanada, H Toyama, Y Yonekura, T Yoshida, K Uemura

    JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM16 ( 5 ) 781 - 793   1996年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:LIPPINCOTT-RAVEN PUBL  

    Recently, two methods have been proposed for regional cerebral blood flow (rCBF) quantitation using [I-123]iodoamphetamine (IMP) and single-photon emission computed tomography (SPECT). The table look-up (TLU) method has been shown to provide both rCBF and volume of distribution, V-d, images from two SPECT scans, while a single-scan autoradiographic (ARG) technique provided rCBF using a fixed and assumed V-d. In both methods, a single blood sample was referred to calibrate the previously determined standard input function The present multicenter project was designed to evaluate the accuracy of both methods for use as clinical investigative tools. Ten independent institutions performed [I-123]IMP-SPECT studies according to both methods in 76 subjects (10 normal volunteers, 32 patients with cerebrovascular disease, and 34 patients with other diseases). Calculated rCBF values were compared with those obtained by the following reference methods available in the participating institutions; [O-15] H2O positron emission tomography (PET) (five institutions), [Xe-133]SPECT (four institutions), and the [I-123]IMP microsphere method (three institutions). Both ARG and TLU methods provided rCBF values that were significantly correlated with those measured by the [O-15] H2O PET technique (p < 0.001 for all subjects; overall regression equation, y = 15.14 + 0.54x) and those measured by the [I-123]IMP-microsphere method (p < 0.001 for all subjects; y = 2.0 + 0.80x). Significant correlation (p < 0.05) was observed in 18 of 24 subjects studied with the [Xe-133] SPECT reference technique (overall regression equation, y = 15.0 + 0.55x). Mean cortical gray matter rCBF in a group of normal subject was 43.9 +/- 3.3 and 33.4 +/- 2.0 ml/min/100 g for the ARG and TLU methods, respectively. Regional V-d of [I-123]IMP estimated by the TLU method was 45 ml/ml +/- 20% in the normal cortical region, Close agreement between ARG and TLU rCBF values was observed (y = -3.21 + 1.07x, r = 0.97), confirming the validity of assuming a fixed V-d in the ARG method. Results of this study demonstrate that both the ARG and TLU methods accurately and reliably estimate rCBF in a variety of clinical settings.

    DOI: 10.1097/00004647-199609000-00003

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  • Decrease in benzodiazepine receptor binding in a patient with Angelman syndrome detected by iodine-123 iomazenil and single-photon emission tomography

    Odano, I, T Anezaki, H Ohkubo, Y Yonekura, Y Onishi, T Inuzuka, M Takahashi, S Tsuji

    EUROPEAN JOURNAL OF NUCLEAR MEDICINE23 ( 5 ) 598 - 604   1996年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER VERLAG  

    A receptor mapping technique using iodine 123 iomazenil and single-photon emission tomography (SPET) was employed to examine benzodiazepine receptor binding in a patient with Angelman syndrome (AS). AS is characterized by developmental delay, seizures, inappropriate laughter and ataxic movement. In this entity there is a cytogenic deletion of the proximal long arm of chromosome 15q11-q13, where the gene encoding the GABA(A) receptor beta 3 subunit (GABRB3) is located. Since the benzodiazepine receptor is constructed as a receptor-ionophore complex that contains the GABA(A) receptor, it is a suitable marker for GABA-ergic synapsis. To determine whether benzodiazepine receptor density, which indirectly indicates changes in GABA(A) receptor density, is altered in the brain in patients with AS, we investigated a 27-year-old woman with AS using I-123-iomazenil and SPET. Receptor density was quantitatively assessed by measuring the binding potential using a simplified method. Regional cerebral blood flow was also measured with N-isopropyl-p-[I-123]iodoampheramine. We demonstrated that benzodiazepine receptor density is severely decreased in the cerebellum, and mildly decreased in the frontal and temporal cortices and basal ganglia, a result which is considered to indicate decreased GABA(A) receptor density in these regions. Although the deletion of GABRB3 was not observed in the present study, we indirectly demonstrated the disturbance of inhibitory neurotransmission mediated by the GABA(A) receptor in the investigated patient. I-123-iomazenil with SPET was useful to map benzodiazepine receptors, which indicate GABA(A) receptor distribution and their density.

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  • Decrease in benzodiazepine receptor binding in a patient with Angelman syndrome detected by iodine-123 iomazenil and single-photon emission tomography 査読

    Odano, I, T Anezaki, H Ohkubo, Y Yonekura, Y Onishi, T Inuzuka, M Takahashi, S Tsuji

    EUROPEAN JOURNAL OF NUCLEAR MEDICINE23 ( 5 ) 598 - 604   1996年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER VERLAG  

    A receptor mapping technique using iodine 123 iomazenil and single-photon emission tomography (SPET) was employed to examine benzodiazepine receptor binding in a patient with Angelman syndrome (AS). AS is characterized by developmental delay, seizures, inappropriate laughter and ataxic movement. In this entity there is a cytogenic deletion of the proximal long arm of chromosome 15q11-q13, where the gene encoding the GABA(A) receptor beta 3 subunit (GABRB3) is located. Since the benzodiazepine receptor is constructed as a receptor-ionophore complex that contains the GABA(A) receptor, it is a suitable marker for GABA-ergic synapsis. To determine whether benzodiazepine receptor density, which indirectly indicates changes in GABA(A) receptor density, is altered in the brain in patients with AS, we investigated a 27-year-old woman with AS using I-123-iomazenil and SPET. Receptor density was quantitatively assessed by measuring the binding potential using a simplified method. Regional cerebral blood flow was also measured with N-isopropyl-p-[I-123]iodoampheramine. We demonstrated that benzodiazepine receptor density is severely decreased in the cerebellum, and mildly decreased in the frontal and temporal cortices and basal ganglia, a result which is considered to indicate decreased GABA(A) receptor density in these regions. Although the deletion of GABRB3 was not observed in the present study, we indirectly demonstrated the disturbance of inhibitory neurotransmission mediated by the GABA(A) receptor in the investigated patient. I-123-iomazenil with SPET was useful to map benzodiazepine receptors, which indicate GABA(A) receptor distribution and their density.

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  • Elevation of cerebral lactate detected by localized 1H-magnetic resonance spectroscopy in migraine during the interictal period

    H. Watanabe, T. Kuwabara, M. Ohkubo, S. Tsuji, T. Yuasa

    Neurology47 ( 4 ) 1093 - 1095   1996年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Lippincott Williams and Wilkins  

    We used localized 1H-magnetic resonance spectroscopy (MRS) to study the metabolic changes in the brains of patients with migraine during the interictal period. Measurement of metabolite levels in the occipital visual cortex in six normal subjects and six patients disclosed high lactate levels in the five patients who had experienced a migraine attack within the previous 2 months. One patient who had not experienced a migraine attack in the previous 4 years did not show a lactate peak. We speculate that anaerobic glycolysis occurs in the brains of patients with migraine during the interictal period, and a long attack-free period may normalize the subclinical metabolic disturbance.

    DOI: 10.1212/WNL.47.4.1093

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  • N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) SPECTによる局所脳血流の定量測定法の比較・検討 査読

    大久保真樹, 小田野行男, 高橋誠, 他

    核医学33 ( 6 ) 647 - 654   1996年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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  • 123I-IMPの分布容積を用いたSPECTによる脳機能診断 査読

    小田野行男, 大久保真樹, 高橋誠, 他

    核医学33 ( 6 ) 579 - 586   1996年

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  • N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) SPECTによる局所脳血流及び分布容積の新しい定量測定法 査読

    大久保真樹, 小田野行男, 高橋誠, 他

    核医学33 ( 3 ) 241 - 249   1996年

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  • FM3A細胞に対する5-FU,CDDPおよび放射線の併用効果に関する研究

    藤田勝三, 大久保真樹, 酒井邦夫

    関越UFT研究会8   9 - 14   1995年12月

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    記述言語:日本語   掲載種別:研究論文(研究会,シンポジウム資料等)  

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  • 5-FUおよびCDDPのFM3A細胞の細胞回転に及ぼす影響 査読

    藤田勝三, 大久保真樹, 酒井邦夫, 日向 浩

    新潟大学医療技術短期大学部紀要5 ( 3 ) 259 - 263   1995年12月

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    記述言語:日本語   掲載種別:研究論文(大学,研究機関等紀要)  

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  • Combined effect of radiation and 5-fluorouracil on survival of FM3A mouse mammary adenocarcinoma cells 査読

    Fujita S, Sakai K, Hicughi S, Sueyama H, Ohkubo M

    Bull Coll Biomed Technol Niigata Univ5 ( 3 ) 265 - 269   1995年12月

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    記述言語:英語   掲載種別:研究論文(大学,研究機関等紀要)  

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  • Can the microsphere model be applied to cerebral blood flow measurement using N-isopropyl-p-[I-123]iodoamphetamine with SPET regardless of washout from brain tissue? 査読

    M Ohkubo, Odano, I, N Takahashi, K Sakai

    NUCLEAR MEDICINE COMMUNICATIONS16 ( 12 ) 1026 - 1033   1995年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CHAPMAN HALL LTD  

    The microsphere model and the continuous withdrawal of arterial blood have commonly been used in clinical studies when measuring regional cerebral blood flow (rCBF) by N-isopropyl-p-[I-123]iodoamphetamine (IMP) single photon emission tomography. The method is considered to underestimate rCBF because of the washout of tracer from brain tissue; however, the extent of this underestimation is not known. To assess whether this underestimation can be determined quantitatively, we performed simulation analysis based on the microsphere model and the two-compartment model [influx, K-1(rCBF); and outflux, k(2)(washout)] using the time-activity curves of I-123-IMP in arterial blood [C-a(t)] of 10 subjects. With the microsphere method, rCBF values fell as time post-injection increased. The extent of underestimation of rCBF was 4.7 +/- 0.28% (mean +/- S.D.) at 5 min, 10.2 +/- 0.42% at 10 min and 15.2 +/- 0.55% at 15 min. There was little variation in the extent of underestimation and it was not dependent on the C-a(t) of the subjects. We therefore considered the results to be generally applicable to various studies of the microsphere model. As 4.7% is considered to be negligible in clinical studies, we conclude that the microsphere model can be applied to obtain accurate measurement of rCBF up to 5 min regardless of washout.

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  • 123I-IMP SPECTを用いたmicrosphere modelに基づく局所脳血流量測定法(簡便法)の精度の検討 査読

    大久保真樹, 小田野行男, 高橋直也

    核医学32 ( 12 ) 1323 - 31   1995年12月

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  • Quantitative assessment of cerebral blood flow measurement using the microsphere model with N-isopropyl-p-[123I]-iodoamphetamine SPECT: simulation analysis for the influence of washout from brain tissue 査読

    Ohkubo M, Odano I, Takahashi N, Sakai K

    Acta Medica et Biologica43 ( 3 ) 165 - 171   1995年9月

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  • EVALUATION OF CEREBRAL BLOOD-FLOW IN PATIENTS WITH IDIOPATHIC ORTHOSTATIC HYPOTENSION USING TC-99M HMPAO BRAIN SPECT DURING POSTURAL TESTING 査読

    ODANO, I, N TAKAHASHI, T HIGUCHI, M OHKUBO, S HAMA, A TSUDA, H OTAKI, E NOGUCHI, M HATANO

    CLINICAL NUCLEAR MEDICINE20 ( 9 ) 807 - 809   1995年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:LIPPINCOTT-RAVEN PUBL  

    To determine whether regional cerebral blood flow (rCBF) would change on standing in patients with idiopathic orthostatic hypotension (IOH), Tc-99m HMPAO SPECT studies were performed during postural testing in five patients with IOH. After 10 minutes of quiet rest on a bed, the patients arose quickly and, at the same time, the radiotracer was injected intravenously. SPECT data were obtained with a ring-type SPECT scanner. Another dose of Tc-99m HMPAO was injected with the subjects in the supine position, and SPECT was performed again, Image subtraction was used to evaluate the change in rCBF caused by postural testing. In all patients, the authors observed a decrease of rCBF in the frontal cortex and basal ganglia. This preliminary study suggests that changes in rCBF occur In patients with IOH on standing, and Tc-99m HMPAO SPECT performed during postural testing may have an important role in evaluating these changes.

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  • 動脈一点採血によるN-isopropyl-p-[123I]iodoamphetamineとSPECTを用いた簡便な脳血流測定法-One-point sampling法- 査読

    小田野行男, 大久保真樹, 高橋直也

    核医学31 ( 10 ) 1219 - 26   1994年10月

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  • 5-FU少量持続静注と放射線の同時併用療法に関する基礎的,臨床的研究 査読

    酒井邦夫, 末山博男, 小田純一, 樋口正一, 土田恵美子, 杉田 公, 松本康男, 藤田勝三, 大久保真樹, 稲越英樹

    INNERVISION9 ( 7 ) 19 - 19   1994年7月

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    その他リンク: http://mol.medicalonline.jp/library/journal/abstract?GoodsID=ab0inerc/1994/000907/009&name=0019-0019j

  • 5-FUと放射線の併用効果に関する基礎的研究

    藤田勝三, 大久保真樹, 酒井邦夫

    関越UFT研究会7   43 - 46   1994年7月

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    記述言語:日本語   掲載種別:研究論文(研究会,シンポジウム資料等)  

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  • A NEW METHOD OF REGIONAL CEREBRAL BLOOD-FLOW MEASUREMENT USING ONE-POINT ARTERIAL SAMPLING BASED ON THE MICROSPHERE MODEL WITH N-ISOPROPYL-P-[I-123]-IODOAMPHETAMINE SPECT 査読

    ODANO, I, M OHKUBO, N TAKAHASHI, T HIGUCHI

    NUCLEAR MEDICINE COMMUNICATIONS15 ( 7 ) 560 - 564   1994年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CHAPMAN HALL LTD  

    We developed a new method for quantitative measurement of regional cerebral blood flow (rCBF) using one-point arterial sampling with N-isopropyl-p-[I-123]-iodoamphetamine (I-123-IMP) and single photon emission computed tomography (SPECT) based on the microsphere model. Although the conventional microsphere method requires both the continuous withdrawal of arterial blood (integral of Ca(t)) and treatment of the blood with octanol to obtain the fraction of true tracer activity in the integral of Ca(t) (N), the new method does not require these two procedures. We examined 14 patients to analyse the correlation between the integral of Ca(t)N and a small arterial sample obtained at one time point [one-point Ca(t)] after the injection of I-123-IMp Without octanol treatment. The integral of Ca(t)N was calculated from one point Ca(t) using the regression line of the correlation. An error of 8.1% in the calculated value compared to the actual value of the integral of Ca(t)N, could be inferred from one-point Ca(t) obtained at 6 min after the injection. Then regional cerebral blood flow was measured by the method and a significant correlation was obtained with rCBF measured using the Xe-133 inhalation method (r = 0.773). The one-point Ca(t) method provides fast, easy, accurate and non-invasive measurement of rCBF without inserting catheters and without treatment of arterial blood with octanol.

    DOI: 10.1097/00006231-199407000-00011

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  • Microsphere modelを用いたN-isopropyl-p-〔123I〕iodoamphetamine (IMP) による局所脳血流定量法の問題点-133Xe SPECTおよび経時的123I-IMP SPECTとの比較検討- 査読

    高橋直也, 大久保真樹, 小野田行男

    核医学31 ( 4 ) 319 - 26   1994年4月

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  • N-isopropyl-p-〔123I〕iodoamphetamine (IMP) と回転型ガンマカメラを用いたmicrosphere modelに基づく脳血流測定法の精度の検討 PaCO2による補正の必要性 査読

    小田野行男, 高橋直也, 大久保真樹

    核医学31 ( 3 ) 223 - 9   1994年3月

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  • MITOCHONDRIAL ENCEPHALOMYOPATHY - ELEVATED VISUAL-CORTEX LACTATE UNRESPONSIVE TO PHOTIC-STIMULATION - A LOCALIZED H-1-MRS STUDY 査読

    T KUWABARA, H WATANABE, K TANAKA, S TSUJI, M OHKUBO, T ITO, K SAKAI, T YUASA

    NEUROLOGY44 ( 3 ) 557 - 559   1994年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:LITTLE BROWN CO  

    We used localized H-1-magnetic resonance spectroscopy (MRS) to study the metabolic changes in the visual cortex of patients with mitochondrial encephalomyopathy. Measurement of metabolite levels in the occipital visual cortex obtained in the dark with seven normal subjects and with four patients (all four of whom had Kearns-Sayre syndrome [KSS]) showed high lactate levels in the patients. Photic stimulation (PS) in four normal volunteers showed that lactate increased immediately after the start of PS and that it decreased to the baseline level with continued PS. Lactate in the resting state was higher in the KSS patients than in the controls, and, unlike the controls, the KSS patients showed no significant elevation of lactate with PS.

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  • H-magnetic resonance spectroscopyにて脳局所での乳酸の上昇を認めた片頭痛

    渡邊浩之, 桑原武夫, 大久保真樹

    新潟大学脳研究所業績集27   127 - 127   1994年

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    記述言語:日本語   掲載種別:研究論文(その他学術会議資料等)  

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  • 1H-magnetic resonance spectroscopyにて脳局所での乳酸の上昇を認めた片頭痛 査読

    渡邊浩之, 桑原武夫, 大久保真樹

    臨床神経学34 ( 5 ) 504 - 507   1994年

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  • 123I-IMP SPECTを用いたmicrosphere modelによるrCBF測定法における洗い出し(k2)の影響

    大久保真樹, 小田野行男, 高橋直也

    新潟核医学懇話会記録集17   33 - 39   1993年11月

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    記述言語:日本語   掲載種別:研究論文(研究会,シンポジウム資料等)  

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  • N-isopropyl-p-[123I]iodoamphetamine (IMP) の分配定数(Distribution volume)とSPECTを用いた新しい診断 Magic Square法の開発 査読

    小田野行男, 大久保真樹, 高橋直也

    核医学30 ( 10 ) 1211 - 9   1993年10月

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  • N-isopropyl-p-[123I] iodoamphetamine (IMP) SPECTにおける分配定数(Distribution volume)を算定するMagic Square法の理論

    小田野行男, 高橋直也, 大滝広雄, 野口栄吉, 羽田野政義, 山崎芳裕, 西原真美子, 大久保真樹

    新潟核医学懇話会記録集16   35 - 39   1993年8月

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    記述言語:日本語   掲載種別:研究論文(研究会,シンポジウム資料等)  

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  • 光刺激で誘発される大脳後頭葉視覚野における乳酸の変化-1H-MRSによるミトコンドリア脳筋症2例の観察- 査読

    桑原武夫, 渡辺浩之, 辻 省次, 田中恵子, 大久保真樹

    医学のあゆみ165 ( 8 ) 491 - 492   1993年5月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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    その他リンク: http://mol.medicalonline.jp/library/journal/abstract?GoodsID=aa7ayuma/1993/016508/017&name=0491-0492j

  • 食道癌高線量率腔内照射用の新しい二重バルーンアプリケータと新しい照射計画プログラム 査読

    稲越英機, 井上富夫, 関谷昌四, 日向 浩, 酒井邦夫, 大久保真樹

    臨床放射線38 ( 5 ) 565 - 569   1993年5月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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    その他リンク: http://search.jamas.or.jp/link/ui/1994069648

  • Changes of 31P-MR Spectroscopy in Experimental Tumors Following Radiotherapy Combined with 5-Fluorouracil Compound (UFT) 査読

    Ohkubo M

    The Tohoku Journal of Experimental Medicine169 ( 3 ) 215 - 223   1993年3月

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    記述言語:英語   掲載種別:学位論文(その他)  

    DOI: 10.1620/tjem.169.215

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  • 123I-IMP脳血流シンチにおけるCrossed Cerebellar Diaschisis(CCD)の発現と再分布現象に関する研究 査読

    小田野行男, 高橋直也, 西原真美子, 大久保真樹

    核医学30 ( 2 ) 189 - 196   1993年

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  • MRIによる脳神経活動の画像化 MR functional brain imaging 査読

    渡辺浩之, 桑原武夫, 大久保真樹

    脳と神経45 ( 10 ) 941 - 944   1993年

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  • Changes of 31P-MR Spectroscopy in Experimental Tumors Following Radiotherapy Combined with 5-Fluorouracil Compound (UFT) 査読

    Masaki Ohkubo

    Tohoku Journal of Experimental Medicine169 ( 3 ) 215 - 223   1993年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The energy metabolism of FM3A tumors in C3H mice following radiotherapy (20 Gy or 40 Gy), 5-fluorouracil compound (UFT) chemotherapy or radiotherapy (20 Gy) combined with UFT was investigated by in vivo 31P-MR spectroscopy on day 2 after treatment. The effects were compared with the growth curves of the tumors and with the cytokinetic and histological changes in the tumors on day 5 after treatment. The combined group (20 Gy+UFT) showed growth curves similar to the 40 Gy group. Cytokinetic and histological changes of the combined group were also similar to those of the 40 Gy group, suggesting supra-additive effect of UFT. 31P-MR spectra of the combined group were similar to those of the 40 Gy group which were characterized by increase of intracellular pH(pHi), decrease of Pi/β-NTP and of PME/total phosphorus-signal ratios. Spectra of the UFT group and the 20 Gy group, on the contrary, showed decrease of pHi, increase of Pi/β-NTP and of PME/total phosphorus-signal ratios. Changes detected by 31P-MR spectroscopy on day 2 were considered to reflect early metabolic events which were correlated to the growth curve, cytokinetic and histological alterations observed on day 5 after treatment. © 1993, Tohoku University Medical Press. All rights reserved.

    DOI: 10.1620/tjem.169.215

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  • 31P-MRスペクトロスコピーからみた放射線単独ならびにUFT併用照射の効果

    大久保真樹, 藤田勝三, 酒井邦夫

    関越UFT研究会5   37 - 41   1992年12月

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  • FM3A細胞に対する温熱併用2分割照射の細胞致死効果 査読

    藤田勝三, 大久保真樹, 樋口健史, 樋口正一, 日向 浩, 酒井邦夫

    新潟大学医療技術短期大学部紀要4 ( 3 ) 285 - 288   1992年8月

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    記述言語:日本語   掲載種別:研究論文(大学,研究機関等紀要)  

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  • 交流電圧計を用いたアナログ計測の開発 査読

    中村久吾, 大久保真樹

    新潟大学医療技術短期大学部紀要4 ( 3 ) 313 - 318   1992年8月

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    記述言語:日本語   掲載種別:研究論文(大学,研究機関等紀要)  

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  • 31P-MR spectroscopy of experimental tumors following irradiation 査読

    Ohkubo M, Sakai K, Fujita S, Ito T, Higuchi T, Kimura M, Yuasa T

    Acta Medica et Biologica40 ( 1 ) 29 - 34   1992年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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    その他リンク: http://dspace.lib.niigata-u.ac.jp/dspace/handle/10191/33374

  • 温熱・放射線併用療法の細胞回転に及ぼす影響 査読

    藤田勝三, 大久保真樹, 樋口健史, 樋口正一, 日向 浩, 酒井邦夫

    新潟大学医療技術短期大学部紀要4 ( 2 ) 201 - 205   1991年8月

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  • マウス移植腫瘍の増殖に伴う31P-MRSの変化 査読

    大久保真樹, 酒井邦夫, 伊藤猛, 他

    日本磁気共鳴医学会雑誌10 ( 4 ) 285 - 293   1990年10月

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  • 放射線とUFTの併用による実験腫瘍の増殖抑制効果 査読

    藤田勝三, 大久保真樹, 酒井邦夫, 日向 浩, 伊藤 猛, 樋口健史

    日本医学放射線学会生物部会誌3 ( 1 ) 65 - 67   1990年9月

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  • MRSの臨床応用

    伊藤 猛, 木村元政, 酒井邦夫, 大久保真樹, 藤田勝三

    新潟医学会雑誌104 ( 9 ) 738 - 744   1990年9月

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  • R-C濾波器の周波数応答測定の一つの試み 査読

    中村久吾, 大久保真樹

    新潟大学医療技術短期大学部紀要4 ( 1 ) 111 - 118   1990年8月

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  • MRスペクトロスコピーによる放射線治療効果の予測に関する研究 査読

    酒井邦夫, 木村元政, 伊藤 猛, 樋口健史, 大久保真樹, 藤田勝三

    INNERVISION5 ( 6 ) 7 - 8   1990年6月

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  • 表在性悪性腫瘍の治療に伴う31P-MRSの変化 査読

    伊藤猛, 酒井邦夫, 大久保真樹

    日本磁気共鳴医学会雑誌10 ( 2 ) 75 - 83   1990年6月

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  • 自然観測係数による母音連鎖の認識 査読

    大久保真樹, 木竜徹, 斉藤義明, 飯島泰蔵

    電子情報通信学会論文誌D−272 ( 12 ) 1985 - 1991   1989年12月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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  • 有限次元の自然観測システムによる音声信号のモデル化 査読

    木竜徹, 大久保真樹, 飯島泰蔵, 斉藤義明

    電子情報通信学会論文誌A72 ( 6 ) 902 - 908   1989年6月

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  • 有限次元の自然観測システムによる音声信号のモデル化

    木竜 徹, 大久保真樹, 斎藤義明, 飯島泰蔵

    電子情報通信学会技術報告88 ( 4 ) 19 - 26   1988年5月

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  • 自然観測法における音声の調音結合・個人差の検討

    大久保真樹, 木竜 徹, 斎藤義明, 飯島泰蔵

    電子情報通信学会技術報告87 ( 70 ) 29 - 38   1987年12月

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  • 咀嚼運動時のEMGにおける時変性反射係数の推定

    木竜 徹, 大久保真樹, 斉藤義明

    電子通信学会技術報告86 ( 36 ) 13 - 20   1986年9月

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  • 筋活動様式とkパラメータとの関連性について

    木竜 徹, 大久保真樹, 斉藤義明

    電子通信学会技術報告86 ( 36 ) 13 - 20   1986年9月

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▶ 全件表示

書籍等出版物

  • 学生のためのExcel

    大久保真樹, 湊 孝子( 担当: 共著 ,  範囲: 区分不可能)

    株式会社 考古堂書店  2004年4月  ( ISBN:4874996086

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    記述言語:日本語 著書種別:学術書

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MISC

  • グルタミン酸CEST-MRイメージング法の開発とアルツハイマー病モデルマウスへの応用

    大野 健, 植木 智志, 大久保 真樹, 鈴木 清隆, 五十嵐 博中, 中田 力

    脳循環代謝31 ( 1 ) 99 - 99   2019年11月

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    記述言語:日本語   出版者・発行元:(一社)日本脳循環代謝学会  

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  • CAD‐quality assuranceのためのSite‐specificな疑似肺結節像生成法の研究

    成田啓廣, 大久保真樹, 村尾晃平, 松本徹, 和田真一

    CT検診25 ( 1 ) 37   2018年2月

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    記述言語:日本語  

    J-GLOBAL

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  • Virtual noduleを用いた胸部CT‐CADの性能特性評価の研究:nodule性状の変化に対する3機種CADの応答

    舩越萌香, 郷戸允, 大久保真樹, 成田啓廣, 村尾晃平, 松本徹, 和田真一, 村松禎久

    CT検診25 ( 1 ) 38   2018年2月

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  • CT装置における逐次近似再構成法での低コントラストファントムを用いたSSP決定法

    原嶋 真吾, 成田 啓廣, 大久保 真樹, 和田 真一

    CT検診25 ( 1 ) 36 - 36   2018年2月

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    記述言語:日本語   出版者・発行元:(NPO)日本CT検診学会  

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  • 3D‐PSF模擬結節を用いた胸部CT‐CADの性能特性評価の研究:結節性状と画像再構成条件の変化に対するCADの応答

    郷戸允, 郷戸允, 大久保真樹, 成田啓廣, 菅原秀賢, 村松禎久, 村尾晃平, 松本徹, 和田眞一

    CT検診24 ( 1 ) 16 - 16   2017年2月

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    記述言語:日本語   出版者・発行元:(NPO)日本CT検診学会  

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  • 19F-3FDG MRIを用いたアルツハイマー病モデルマウス脳代謝マッピング

    藤原 秀元, 五十嵐 博中, 鈴木 雄治, 大久保 真樹, 中村 亨弥, 辻田 実加, 藤井 幸彦, 中田 力

    脳循環代謝28 ( 1 ) 161 - 161   2016年11月

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    記述言語:日本語   出版者・発行元:日本脳循環代謝学会  

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  • 3D‐PSF模擬結節を用いた胸部CT‐CADの性能評価の研究

    郷戸允, 郷戸允, 大久保真樹, 成田啓廣, 菅原秀賢, 村尾晃平, 松本徹, 和田眞一

    CT検診23 ( 1 ) 30 - 30   2016年2月

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    記述言語:日本語   出版者・発行元:(NPO)日本CT検診学会  

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  • マウスVBM用のMRI標準脳の開発とアルツハイマー病モデルマウスを用いたVBMの有用性の検証

    八木 悠太, 植木 智志, 伊藤 浩介, 辻田 実加, 五十嵐 博中, 大久保 真樹

    日本放射線技術学会雑誌71 ( 9 ) 932 - 933   2015年9月

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    記述言語:日本語   出版者・発行元:(公社)日本放射線技術学会  

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    記述言語:日本語   出版者・発行元:(公社)日本放射線技術学会  

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  • Virtual noduleを用いた胸部CT検診CAD‐QAにおけるnodule offsetの影響―ファントム模擬結節による検証―

    吉田皓文, 大久保真樹, MARASINGHE Janaka C, 和田真一, 村尾晃平, 松本徹

    日本放射線技術学会東北部会雑誌 ( 24 ) 100 - 100   2015年1月

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    記述言語:日本語   出版者・発行元:(公社)日本放射線技術学会-東北支部  

    J-GLOBAL

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  • PSF‐CT画像シミュレーションと胸部CT検診画像の融合を用いたCAD性能評価の研究

    小林元, 大久保真樹, MARASINGHE Janaka C, 村尾晃平, 松本徹, 曽根脩輔, 和田真一

    医学物理 Supplement32 ( 3 ) 141 - 142   2012年9月

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    記述言語:日本語  

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  • Phase sensitive inversion recovery(PSIR)法の肝臓EOB検査の有用性

    内藤 健一, 金沢 勉, 斉藤 宏明, 粥川 啓廣, 大久保 真樹, 木村 元政, 高野 徹

    日本放射線技術学会雑誌68 ( 9 ) 1176 - 1177   2012年9月

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    記述言語:日本語   出版者・発行元:(公社)日本放射線技術学会  

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  • 肺内結節検出CADシステムの性能評価法の研究―virtual noduleを用いた検討

    和田真一, 大久保真樹, 小林元, MUNAWEERA Chathari M, 村尾晃平, 松本徹, 曽根脩輔

    医学物理 Supplement32 ( 1 ) 123   2012年4月

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    J-GLOBAL

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  • 脳動脈瘤クリップの静磁場方向に対する角度が磁化率アーチファクトに及ぼす影響

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    日本放射線技術学会総会学術大会予稿集68回   125 - 125   2012年2月

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    記述言語:日本語   出版者・発行元:(公社)日本放射線技術学会  

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  • 肺内結節検出用CT‐CADの性能検証法の研究―virtual noduleを用いた検討

    和田真一, 大久保真樹, 舟木歩, 村尾晃平, 松本徹, 曽根脩輔

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    記述言語:日本語   出版者・発行元:(NPO)日本CT検診学会  

    J-GLOBAL

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  • 小児大脳型adrenoleukodystrophy患者脳の発症極早期からの経時的評価 3.0テスラMR装置によるDTIと1H-MRSI解析

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    脳と発達43 ( 4 ) 332 - 332   2011年7月

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    記述言語:日本語   出版者・発行元:(一社)日本小児神経学会  

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  • IGRTにおける位置照合の容易化を目的としたEPIDポータル画像の周波数処理法の考案

    山田 昌法, 大久保 真樹, 粥川 啓廣, 楠本 敏久, 三浦 貴, 松浦 将孝, 山田 宏美

    日本放射線技術学会総会学術大会予稿集67回   256 - 256   2011年2月

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    記述言語:日本語   出版者・発行元:(公社)日本放射線技術学会  

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  • PSF‐CT画像シミュレーションと人体ファントム画像融合を用いた肺内結節体積測定精度評価の研究

    舟木歩, 和田真一, 大久保真樹, 村尾晃平, 松本徹

    CT検診18 ( 1 ) 48 - 48   2011年1月

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    記述言語:日本語   出版者・発行元:(NPO)日本CT検診学会  

    J-GLOBAL

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  • PSF-CT画像シミュレーションと統計学的手法を用いた低線量CT検診撮影条件決定法の検証

    金井 悟史, 和田 真一, 大久保 真樹, 粥川 啓廣, 樫村 康弘, 大野 健, 舟木 歩, 原田 潤, 近藤 智史, 武田 聡司, 大棒 秀一, 松本 徹, 宮本 忠昭

    CT検診18 ( 1 ) 49 - 49   2011年1月

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    記述言語:日本語   出版者・発行元:(NPO)日本CT検診学会  

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  • 肝臓dynamic MRIにおける動脈優位相でのアーチファクトに関する検討

    内藤 健一, 深谷 貴広, 斉藤 宏明, 瀧本 宗徳, 大久保 真樹, 粥川 啓廣

    日本放射線技術学会東北部会雑誌 ( 19 ) 94 - 95   2010年2月

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    記述言語:日本語   出版者・発行元:(公社)日本放射線技術学会-東北支部  

    肝臓dynamic MRIにおける動脈優位相でのアーチファクトについて検討した。肝特異性造影剤Gd-EOB-DTPA(EOB)を用いたテストインジェクションのデータを参考に、模擬的に時間濃度曲線を作成した。時間濃度曲線上で、撮像時間および撮像開始のタイミングを想定し、その間の濃度曲線の変化パターンを用いた。この変化パターンに基づいて、k-spaceにおける位相エンコード方向の各データを変調した。撮像時間20秒の場合、セントリック法にて、造影剤の立ち上がり時に撮像が開始された場合、輪郭強調の影響がみられた。逆に立ち下がり時に撮像が開始された場合、ボケが生じた。これらの影響は、撮像時間が短い(10秒)方が小さかった。また、シーケンシャル法では、撮像時間、タイミングに関わらずこれらのアーチファクトはほとんどみられなかった。

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  • Gd-EOB-DTPA造影MRIにおける動脈優位相でのアーチファクトに関する検討

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    日本放射線技術学会総会学術大会予稿集66回   251 - 251   2010年2月

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    記述言語:日本語   出版者・発行元:(公社)日本放射線技術学会  

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  • LIDC画像を用いた肺がんCT検診CADシステムのロバスト化効果の検討

    和田真一, 松本徹, 村尾晃平, 粥川啓廣, 大久保真樹

    CT検診17 ( 1 ) 41 - 41   2010年1月

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    記述言語:日本語   出版者・発行元:(NPO)日本CT検診学会  

    J-GLOBAL

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  • 精度管理された胸部CT検診の普及を目指す研究プロジェクトについて

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    医学物理 Supplement29 ( 2 ) 216 - 217   2009年4月

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    記述言語:日本語  

    J-GLOBAL

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  • SSPを用いたCT画像の体軸方向分解能変換の研究

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    記述言語:日本語  

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    記述言語:日本語   出版者・発行元:(一社)日本脳神経外科学会  

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  • PSF画質変換によるCT-CADシステムのロバスト性評価

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    記述言語:日本語  

    CiNii Article

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  • 胸部CT‐CADシステムのPSF画質変換によるロバスト化

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    CT検診15 ( 1 ) 26 - 27   2008年1月

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    記述言語:日本語   出版者・発行元:(NPO)日本CT検診学会  

    J-GLOBAL

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  • CADのためのCT画像画質変換処理(多機種CT装置画質対応CADへの応用の検討)

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    記述言語:日本語  

    J-GLOBAL

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  • 統合失調症における帯状回グルタミン酸と帯状束拡散異方性

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    神経化学45 ( 2-3 ) 486 - 486   2006年8月

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    記述言語:日本語   出版者・発行元:日本神経化学会  

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  • 脊髄小脳変性症の小脳のMagnetic Resonance Spectroscopy(MRS)

    桑原 武夫, 大久保 真樹, 中田 力, 辻 省次

    臨床神経学39 ( 1 ) 208 - 208   1999年1月

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    記述言語:日本語   出版者・発行元:(一社)日本神経学会  

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共同研究・競争的資金等の研究

  • CT画像の空間分解能および結節の特徴に基づいたバーチャル3D肺がん像生成法の開発

    2017年04月 - 現在

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    大久保 真樹

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    担当区分:研究代表者  資金種別:競争的資金

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  • CT装置の空間分解能を活用したバーチャル3D肺がん像生成およびCADへの応用

    2014年04月 - 2017年03月

    日本学術振興会  科学研究費助成事業  基盤研究(C)

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    資金種別:競争的資金

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  • 肺がんCT診断支援システムに適する画質への画像変換法の開発

    2011年04月 - 2014年03月

    日本学術振興会  科学研究費助成事業  基盤研究(C)

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    資金種別:競争的資金

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  • X線CT装置の空間分解能を活用した定量的な画像診断能の向上に関する研究

    2008年04月 - 2011年03月

    日本学術振興会  科学研究費助成事業  基盤研究(C)

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    資金種別:競争的資金

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  • 超高磁場MR装置を用いたプロトンスペクトロスコピーに関する基礎研究

    1998年04月 - 2000年03月

    科学研究費助成事業  奨励研究(A)

      詳細を見る

    資金種別:競争的資金

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  • 123I-IMP SPECTを用いたマイクロスフェア法による脳血流量測定法の評価

    1994年04月 - 1995年03月

    科学研究費助成事業  奨励研究(A)

      詳細を見る

    資金種別:競争的資金

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  • 13C-MRスペクトロスコピーによる実験腫瘍の増殖・放射線照射に伴う組織代謝変化

    1992年04月 - 1993年03月

    科学研究費助成事業  奨励研究(A)

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    資金種別:競争的資金

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  • MRスペクトロスコピーによる腫瘍組織の代謝に関する研究

    1991年04月 - 1992年03月

    科学研究費助成事業  奨励研究(A)

      詳細を見る

    資金種別:競争的資金

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