資料
MDCTの被ばく線量評価－人体等価ファントムによる臓器線量と実効線量の測定－
キーワード:
multi-detector CT,
anthropomorphic phantom,
fluorescent glass dosimeter,
organ dose,
effective dose
2010 年 66 巻 8 号 p. 901-910
詳細
2010 年 66 巻 8 号 p. 901-910
In order to evaluate the exposure dose in CT examinations, we measured the tissue and organ doses by test site in 4-row, 16-row, and 64-row multi detector CT by using an anthropomorphic phantom and fluorescent glass dosimeters. Furthermore, we calculated the effective dose by using the tissue weighting factor recommended by the ICRP in 2007. The effective dose in the head and neck examinations was 1.4–3.1 mSv, whereas the maximum skin dose was 278.9 mGy in head perfusion CT. The effective dose in examinations of the body trunk was 10.1–35.2 mSv. In addition, the organ dose and skin dose in the scanning range was similar to the CTDIvol in head and neck examinations, while it was higher than the CTDIvol in examinations of the body trunk. The exposure dose of patients undergoing CT is high in comparison to other radiological examinations. As a result, due to consecutive examinations, an absorbed dose of more than 100 mGy is possible. A future problem therefore remains how to lower the overall exposure dose with the introduction of new radiographic diagnostic modalities, such as phase scan or coronary CT angiography.
