安徽省CT机剂量与低对比度分辨力的检测与分析

目的　全省CT机辐射剂量水平与低对比度分辨力之间的关系。方法　根据卫生部规定的统一方法[1] 。结果　 177台CT机 ,头部中心平均CTDI2 7.8mGy ,体部中心平均CTDI9.2mGy ;177台CT机中 2 1台低对比度检测不合格和合格时头部中心平均CTDI分别为 :2 3.9mGy、39.7mGy。 5 6台一手机中有 3台低对比度分辨力首次检测不合格。结论　低对比度分辨力在头部中心剂量 30mGy～ 5 0mGy为最佳 ,同时必须加强对CT机检测 ,才能保证其应用质量

Measurement and Analysis of Relation between Low-contrast Resolution and CT Dose in Anhui Province

Objective To understand relation between CT scanner radiation levels and low-contrast resolution in whole province. Methods Radiation doses were measured According to standard rules of Ministry of Health. Results By 177 CT scanner measured, average dose of head center was CTDI 27.8 mGy and that of Body center, was CTDI 9.2 mGy. Radiation dose of 21 CT scanners was unqualified, pass fail: 23.9 mGy, passed: 39.7 mGy. There were 3 CT scanners cannot pass low-contrast resolution test. Conclusions the best radiation dose should be 30 mGy-50mGy and the routine test of CT scanner should be performed to ensure the image quality of CT scanner.