Measurement and analysis of radiation doses received by the human body and radiation levels in the CT room under digital miniature CT scanning conditions
10.13491/j.issn.1004-714X.2025.03.011
- VernacularTitle:数字化小型CT扫描条件下人体受照剂量及机房内辐射水平测量与分析
- Author:
Lin YIN
1
;
Zhenhua YANG
1
;
Yaqi XI
1
;
Wenlong FAN
1
;
Rui YANG
1
;
Qisheng XIA
1
;
Qiaoling WU
1
Author Information
1. China-Japan Friendship Hospital, Beijing 100029, China.
- Publication Type:OriginalArticles
- Keywords:
Digital miniature CT;
Equivalent dose;
Ambient equivalent dose rate;
Radiation protection
- From:
Chinese Journal of Radiological Health
2025;34(3):373-377
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the radiation impact of a self-developed digital miniature CT on the human body and the environment under simulated scanning conditions, and verify its safety and regulatory compliance. Methods Under typical head scanning conditions with the digital miniature CT (70 kV/10 mA), the equivalent doses received at the body surface sites corresponding to the thyroid, breast, stomach, liver, kidney, and gonads of the phantom were measured without protection and with 0.5 mmPb equivalent protection using LiF (Mg, Cu, P) thermoluminescent dosimeters. The ambient dose equivalent rates at the bed level inside the CT room at different directions and distances from the scanning center were measured using a model AT1121 X/γ dosimeter. The equivalent doses of organs on both sides of the phantom and the ambient equivalent dose rates on the left and right sides of the longitudinal axis of the bed in the CT room were compared. The Mann-Whitney test was used at a significance level of P < 0.05. Results During a single scan of the head with the digital miniature CT, the equivalent doses at the body surface sites corresponding to the thyroid, breast, stomach, liver, kidney, and gonads without protection were 1.04, 0.95, 0.55, 0.57, 0.40, and 0.12 mSv, respectively, which were only 0.84% to 8.24% of the doses inside the irradiation field. With 0.5 mm Pb equivalent protection, the equivalent dose of the thyroid decreased from 8.24 mSv to 3.27 mSv with a reduction of 60.3%, and the doses of the other organs were reduced to 1.5-11.5 μSv with the maximum reduction of 14 times. In the longitudinal axis direction of the CT bed, the ambient dose equivalent rate at a distance of 2 m from the scanning center was reduced to 0.066 mSv/h, which was only 9.6% of the ambient equivalent dose rate at a distance of 50 cm from the scanning center. Conclusion The digital miniature CT has advantages in ensuring patient safety, optimizing imaging quality, and promoting technological development, demonstrating promising application potential. However, the radiation protection of personal and CT room should not be ignored.
