押尾 晃一 (オシオ コウイチ)

Oshio, Koichi

写真a

所属(所属キャンパス)

医学部 放射線科学教室(診断) (信濃町)

職名

専任講師

外部リンク

学歴 【 表示 / 非表示

  •  

    南カリフォルニア大学, 工学部, 医用工学

    米国, 大学院, 修了, 博士

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    慶應義塾, 医学部

    大学, 卒業, その他

 

論文 【 表示 / 非表示

  • Quantification of edematous changes by diffusion magnetic resonance imaging in gastrocnemius muscles after spinal nerve ligation

    Abe Koji, Nakamura Toshiyasu, Yamabe Eiko, Oshio Koichi, Miyamoto Takeshi, Nakamura Masaya, Matsumoto Morio, Sato Kazuki

    PLoS One 13 ( 2 )  2018年02月

    ISSN  1932-6203

     概要を見る

    <p>Patients with complex regional pain syndrome (CRPS) exhibit diverse symptoms, such as neuropathic pain, allodynia, local edema and skin color changes in the affected lesion. Although nerve injury may cause CRPS, pathophysiological mechanisms underlying the syndrome are unclear, and local edema, a characteristic of CRPS, has not been evaluated quantitatively for technical reasons. Here, using a rat spinal nerve ligation-induced CRPS model, we show that edematous changes in gastrocnemius muscle can be detected quantitatively by diffusion magnetic resonance imaging (MRI). Using the line-scan diffusion spectrum on a 1.5 T clinical MR imager, we demonstrate significant elevation of the apparent diffusion coefficient (ADC) ratios in gastrocnemius muscle on the ligated versus the sham-operated rats by one day after surgery, those ratios gradually decreased over time. Meanwhile, T2 ratios in gastrocnemius muscle on the ligated rats increased gradually and significantly, peaking two weeks after surgery, and those ratios remained high and were consistent with edema. Expression of vascular endothelial growth factor (VEGF), a key regulator of blood vessel formation and function, was significantly lower in gastrocnemius muscle on the ligated versus non-ligated side, suggesting that nerve ligation promotes edematous changes and perturbs VEGF expression in target muscle.</p>

  • A single-shot T<inf>2</inf> mapping protocol based on echo-split gradient-spin-echo acquisition and parametric multiplexed sensitivity encoding based on projection onto convex sets reconstruction

    Chu M., Chang H., Oshio K., Chen N.

    Magnetic Resonance in Medicine (Magnetic Resonance in Medicine)  79 ( 1 ) 383 - 393 2018年01月

    ISSN  07403194

     概要を見る

    © 2017 International Society for Magnetic Resonance in Medicine Purpose: To develop a high-speed T2 mapping protocol that is capable of accurately measuring T2 relaxation time constants from a single-shot acquisition. Theory: A new echo-split single-shot gradient-spin-echo (GRASE) pulse sequence is developed to acquire multicontrast data while suppressing signals from most nonprimary echo pathways in Carr-Purcell-Meiboom-Gill (CPMG) echoes. Residual nonprimary pathway signals are taken into consideration when performing T2 mapping using a parametric multiplexed sensitivity encoding based on projection onto convex sets (parametric-POCSMUSE) reconstruction method that incorporates extended phase graph modeling of GRASE signals. Methods: The single-shot echo-split GRASE-based T2 mapping procedure was evaluated in human studies at 3 Tesla. The acquired data were compared with reference data obtained with a more time-consuming interleaved spin-echo echo planar imaging protocol. T2 maps derived from conventional single-shot GRASE scans, in which nonprimary echo pathways were not appropriately addressed, were also evaluated. Results: Using the developed single-shot T2 mapping protocol, quantitatively accurate T2 maps can be obtained with a short scan time (<0.2 seconds per slice). Conclusion: Accurate T2 mapping with minimal signal contamination from CPMG high-order echo pathways can be achieved by the developed method that integrates single-shot echo-split GRASE acquisition and parametric-POCSMUSE reconstruction. Magn Reson Med 79:383–393, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

  • A single-shot T2 mapping protocol based on echo-split gradient-spin-echo acquisition and parametric multiplexed sensitivity encoding based on projection onto convex sets reconstruction

    Chu Mei Lan, Chang Hing Chiu, Oshio Koichi, Chen Nan kuei

    Magnetic Resonance in Medicine 2017年

    ISSN  0740-3194

     概要を見る

    <p>Purpose: To develop a high-speed T2 mapping protocol that is capable of accurately measuring T2 relaxation time constants from a single-shot acquisition. Theory: A new echo-split single-shot gradient-spin-echo (GRASE) pulse sequence is developed to acquire multicontrast data while suppressing signals from most nonprimary echo pathways in Carr-Purcell-Meiboom-Gill (CPMG) echoes. Residual nonprimary pathway signals are taken into consideration when performing T2 mapping using a parametric multiplexed sensitivity encoding based on projection onto convex sets (parametric-POCSMUSE) reconstruction method that incorporates extended phase graph modeling of GRASE signals. Methods: The single-shot echo-split GRASE-based T2 mapping procedure was evaluated in human studies at 3 Tesla. The acquired data were compared with reference data obtained with a more time-consuming interleaved spin-echo echo planar imaging protocol. T2 maps derived from conventional single-shot GRASE scans, in which nonprimary echo pathways were not appropriately addressed, were also evaluated. Results: Using the developed single-shot T2 mapping protocol, quantitatively accurate T2 maps can be obtained with a short scan time (&lt;0.2 seconds per slice). Conclusion: Accurate T2 mapping with minimal signal contamination from CPMG high-order echo pathways can be achieved by the developed method that integrates single-shot echo-split GRASE acquisition and parametric-POCSMUSE reconstruction.</p>

  • Diffusion-weighted MR imaging for the assessment of renal function

    Yamada Kentaro, Shinmoto Hiroshi, Oshio Koichi, Ito Seigo, Kumagai Hiroo, Kaji Tatsumi

    Magnetic Resonance in Medical Sciences 15 ( 2 ) 237 - 245 2016年04月

    ISSN  1347-3182

     概要を見る

    <p>Purpose: To determine the appropriateness of statistical models using the truncated Gaussian distribution and gamma distribution for diffusion signal decay, and to assess the correlation between the parameters obtained from the statistical models and estimated glomerular filtration rate (eGFR). Methods: Twenty-nine patients with chronic kidney disease and 21 healthy volunteers were included and classified in four groups according to eGFR (ml/min/1.73 m2): group 1 (90 ≤ eGFR, n = 10), group 2 (eGFR 60–90, n = 15), group 3 (eGFR 30–60, n = 17), and group 4 (eGFR &lt;30, n = 8). Diffusion-weighted imaging using five b-values (0, 500, 1000, 1500, and 2000 s/mm2) was performed. Truncated Gaussian and gamma models were compared for goodness of fit. Area fractions for the diffusion coefficient D &lt;1.0 × 10-3 mm2/s (Frac &lt;1.0) and D &gt; 3.0 × 10-3 mm2/s (Frac &gt; 3.0) obtained from the statistical model were compared among four groups. Correlation between proposed parameters and conventional apparent diffusion coefficient (ADC) with eGFR was calculated. Results: There was no significant difference in goodness of fit between the truncated Gaussian and gamma models. Frac &lt;1.0 and Frac &gt; 3.0 showed good correlation with eGFR, as did ADC. Comparison between groups 1 and 2 showed that only Frac &lt;1.0 in both distribution models had significant differences. Conclusion: Statistical models yield robust interpretation of diffusion magnetic resonance (MR) signals with relevance to histological changes in the kidney. The parameters of the statistical models, particularly Frac &lt;1.0, strongly correlated with eGFR.</p>

  • Removing ambiguity caused by T2 shine-through using weighted diffusion subtraction (WDS)

    Oshio Koichi, Okuda Shigeo, Shinmoto Hiroshi

    Magnetic Resonance in Medical Sciences 15 ( 1 ) 146 - 148 2016年

    ISSN  1347-3182

     概要を見る

    <p>We propose a novel image processing technique that combines images routinely acquired with low and high b values to create a single image that contains clinically useful information without the ambiguity of T2 shine-through. The contrast of resulting images is similar to that of a T2 image, but the signals of pixels with low apparent diffusion coefficient (ADC) values are inverted. The proposed technique takes the threshold ADC value as the one adjustable parameter.</p>

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KOARA(リポジトリ)収録論文等 【 表示 / 非表示

研究発表 【 表示 / 非表示

  • A Novel Method for Displaying Multidetector CT Urography -Top Ten Prejection-

    Jinzaki Masanori, Oshio Koichi, Silverman G Stvart, Imai Yasuhiro, Sato Kozo, Kuribayashi Sachio

    Radiological Society of North America 88th Scientific Assembly and Annual Meeting, 2002年11月, ポスター(一般)

  • MDCT angiography for renal artery

    Sato Kozo, Jinzaki Masahiro, Matsumoto Kazuhiro, Oshio Koichi, Kuribayashi Sachio

    international 3D workshop, 2002年06月, その他

  • MDCT urography の臨床応用

    陣崎雅弘,押尾晃一,杉浦弘明,谷本伸弘,新本弘,栗林幸夫

    第61回日本医学放射線学会学術発表会, 2002年04月, 口頭(一般)

  • IS MR Thermometry Accurate during Radiofrequency Ablation (RFA) ?

    Okuda Shigeo, Kuroda Kagayaki, Oshio Koichi, Fujiwara Hirokazu, Kurata Tadayoshi, Kuribayashi Sachio

    Radiological Society of North America (RSNA)2001 (87th ; 2001 ; Chicago,IL,USA), 2001年11月

  • MDCT urographyの臨床応用―厚み情報を保存した新しいプロジェクション法 (TTP)を用いて―

    陣崎雅弘,押尾晃一,谷本伸弘,佐藤浩三,新本弘,栗林幸夫

    第1回3次元画像解析・レーザーフォーラム, 2001年10月

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知的財産権等 【 表示 / 非表示

  • 磁気共鳴イメージング装置

    特願: 2004-364765  2004年12月 

    特許: 3668816  2005年04月

    特許, 単独

受賞 【 表示 / 非表示

  • Cum Laude

    Hiramatu Hideko,Oshio Kouichi,Ikeda Tadashi,Enomoto Kouji,Mukai Makio,Hiramatsu Kyouichi, 1997年12月, 83rd Annual Meeting Radiological Society of North America