| Project/Area Number |
10670864
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Radiation science
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| Research Institution | IBARAKI PREFECTURAL UNIVERSITY OF HEALTH SCIENCES |
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Principal Investigator |
INADA Tetsuo Ibaraki Prefectural University of Health Sciences, Dept. of Radiological Sciences, Prof., 保健医療学部, 教授 (50114038)
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| Co-Investigator(Kenkyū-buntansha) |
SATOH Hitoshi Ibaraki Prefectural University of Health Sciences, Dept. of Radiological Sciences, Assistant, 保健医療学部, 助手 (90285057)
ABE Shinji Ibaraki Prefectural University of Health Sciences, Dept. of Radiological Sciences, Assistant, 保健医療学部, 講師 (00274978)
NISHIMURA Katsuyuki Ibaraki Prefectural University of Health Sciences, Dept. of Radiological Sciences, Prof., 保健医療学部, 教授 (10129158)
SEKINE Norio Ibaraki Prefectural University of Health Sciences, Dept. of Radiological Sciences, Assistant, 保健医療学部, 助手 (70295434)
FUJISAKI Tatsuya Ibaraki Prefectural University of Health Sciences, Dept. of Radiological Sciences, Assistant, 保健医療学部, 助手 (00285058)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1999: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1998: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | Heavy Ion Radiography / Carbon Ion Beam / Density Resolution / Quantum Mottle / Radiation Injury / Microchannel-plate / CT-image Reconstruction / Residual Range Distribution / 重イオン線 / ラジオグラフィ / コントラスト分解能 / MTF(Modular Transfer Function) / 撮影被曝線量 / 画像情報処理 / 残留飛程 / 重イオンCT |
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| Research Abstract |
Studies of efficacy on heavy ion radiography have been performed in comparison with X-ray radiography. It was suggested that heavy ion radiography gave superior imaging for low contrast tumors at relatively low radiation levels. In heavy ion radiography, small difference of tissue density in deep seated area can be recorded on films as the difference of optical density by using a distal edge of the Bragg peak. This shows that the difference in optical density is related to the difference of the residual range at the film position. The residual range is determined as the integrated stopping power along the path of particle. It was suggested that the two dimensional distribution of relative stopping power could be calculated by the use of a set of data, namely, one dimensional (1D) residual range distributions for the different directions over 360 degrees. The residual range is determined as the accumulated effect of stopping power along the path of charged particle. If we have the set of images showing residual range distribution for the different directions over 360 degrees, the distribution of electron density could be calculated by the use of stopping power formula. This work begin with formulation of algorithm to obtain the CT image of electron density from the spatial distribution of residual range. In the previous study the relations between optical density and residual range and those between optical density and absorbed dose were determined using film system and the difference of residual ranges at each internal organ of small animal. In the present study the fluorescent screen and video-camera with I.I. system was adapted to shorten the image collection time. One dimentional distribution of residual range was obtained from the series of projection images of cylindrical aclylate phantom experimentally by changing thickness of the range shifter.
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