2018 Fiscal Year Final Research Report
Investigation into the current status of radiation exposure in Japanese infant CT examinations using an in-phantom dosimetry system
| Project/Area Number |
16K09014
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Medical Physics and Radiological Technology
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| Research Institution | Nagoya University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
藤井 啓輔 名古屋大学, 医学系研究科(保健), 講師 (40469937)
今井 國治 名古屋大学, 医学系研究科(保健), 教授 (20335053)
池田 充 名古屋大学, 医学系研究科(保健), 教授 (50184437)
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| Research Collaborator |
AKAHANE keiichi
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Keywords | 放射線防護 / 医療被ばく / 乳幼児CT / 人体ファントム |
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| Outline of Final Research Achievements |
In this study, to investigate the current status of radiation exposure in Japanese infant CT examinations, we developed a Japanese 0.5-year-old head-chest phantom and constructed an in-phantom dosimetry system consisting of radiophotoluminescence glass dosemeters installed at various tissue/organ sites within the phantom. In addition, we quantitatively and qualitatively evaluated the image noise of diagnostic images in head CT examinations, and investigated the optimization of head CT examination from the relationship between image noise, patient age, examination purpose, head shape, and radiation dose. On the other hand, we devised an internal dose distribution measurement system based on the luminescence from polymer materials by X-ray irradiation and verified its accuracy. This system can more economically and easily measure the dose distribution than conventional methods and will provide useful dose information in the risk assessment and the optimization of CT examinations.
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| Free Research Field |
放射線計測学
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| Academic Significance and Societal Importance of the Research Achievements |
わが国では、X線CT検査による子供の被ばくリスクが大きな社会問題となっているが、CT検査の最適化や、被ばくリスクの推定精度の検証に必要な臓器線量データは皆無であった。本研究ではこの問題を解決すべく、日本人体型を模擬した人体ファントムによる線量評価により、乳幼児において実施頻度が最も高い頭部CT検査の臓器線量レベルを明らかにした。同時に、診断画像を基に、画質と線量との関係を年齢、検査目的、頭部形状別に調べることで、年齢別に最適検査条件を提案した。本研究で得られた線量や画質データは、検査の最適化だけでなく、より効果的な放射線防護法の開発や、リスク推定の精度向上に大いに役立つであろう。
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