2 0 0 0 OA 診断X線検査による乳幼児, 小児, 成人の被ばく線量
- 著者
- 青山 隆彦 小山 修司 川浦 稚代 杉本 成人 藤井 啓輔 瀬口 繁信 川崎 稔生
- 出版者
- 日本保健物理学会
- 雑誌
- 保健物理 (ISSN:03676110)
- 巻号頁・発行日
- vol.47, no.4, pp.270-281, 2012 (Released:2013-12-17)
- 参考文献数
- 17
- 被引用文献数
- 1
Data are presented on radiation doses to infant, child and adult patients undergoing head, chest and abdominal CT examinations with recent multi-detector row CT scanners (MDCT). Also presented are dose data in CT coronary angiography(CTCA) observed with Toshiba 320MDCT and Siemens 64MDCT. The doses were measured using newborn, 6-year-child and adult anthropomorphic phantoms, in which photodiode dosimeters were implanted at various tissue and organ positions. Measured doses were used to evaluate organ and effective doses. Organ doses in the scan region obtained in head CT were 20-40 mGy for infants and children, and 40-70 mGy for adults. Effective doses in head CT were 2.1-3.3 mSv for infants,and 1.0-2.0 mSv for children and adults. These doses in chest CT were 3-9 mGy and 2-6 mSv for infants, 2-12 mGy and 1-7 mSv for children, and 5-35 mGy and 7-14 mSv for adults. In abdominal CT they were 3-14 mGy and 2-10 mSv for infants, 4-18 mGy and 3-12 mSv for children, and 10-48 mGy and 9-21 mSv for adults. In CTCA radiation doses for helicalscan without using dose modulation were reduced to less than 1/6 and 1/10 by using prospectively gated axial scan of Toshiba320MDCT and “Flash Spiral” scan of Siemens 64MDCT, respectively.
1 0 0 0 OA 確率共鳴を利用した脳梗塞部の検出と被ばく線量軽減-ノイズは本当に有害因子なのか?
本申請研究の主たる目的は、CT検査時における被ばく線量(重要臓器線量)を測定した上で、申請者がCT画像上で発現に成功させた確率共鳴現象を利用して、病変検出能の向上を図ると共に、CT検査時の被ばく線量軽減を行うことである。特に今回は脳梗塞部の検出(脳溝の狭小化や早期虚血性病変)に主眼を置き、どのような条件の時に効果的に確率共鳴が発現するかを検討し、最終的に臨床への応用を目指す。確率共鳴はノイズ強度が10HUの時に最も効率よく発現し、コントラスト分解能も鮮鋭度も大きく改善した。また、この改善効果はノイズの種類に依存し、高周波を多く含むノイズを付加した際に、その効果が大きくなることを定量的に示した。