四川省CT机质量控制与辐射防护检测结果分析

Detection and Analysis on CT Machine Quality Control and Radiation Protection in Sichuan Province

目的通过对70台CT机质量控制和40个CT机房辐射防护效果检测,了解CT机性能状况和机房放射防护情况,以便研究提高CT机质量控制和机房辐射防护效果的措施。方法参照《X射线计算机断层摄影装置质量保证检测规范》GB17589-2011、《X射线计算机断层摄影放射防护要求》GBZ165-2012和《医用X射线诊断放射防护要求》GBZ130-2013的方法和要求进行检测和评价。结果所检的70台CT机性能指标中高对比分辨力、低对比可探测能力、诊断床定位精度三项指标的合格率分别为100%,定位光精度、重建层厚偏差、水的CT值、均匀性四项指标的合格率分别为98.6%,CT剂量指数合格率为97.1%,噪声合格率为81.4%,CT值线性合格率仅为68.6%,70台CT机中只有28台CT机所检性能指标完全符合国家标准要求。40个机房辐射防护控制水平检测结果全部小于2.5μSv·h-1,符合国家标准限值要求。结论 CT机的性能指标中关键性指标合格率较高,但噪声和线性合格率较低,因此医院在配置CT机的同时,应加强对CT机的质量控制,做好稳定性检测和维护,保证CT机的良好性能。CT机房辐射防护控制水平检测结果全部符合国家限值要求。

Objective To conduct the quality control of 70 CT machine and detect the protection effect of 40 CT rooms,and to understand the performance of the CT machine and the protection of CT room. Methods According to the standards of GB17589- 2011,GBZ165- 2012 and GBZ130- 2013,detection and evaluation were conducted. Results The qualified rate of high contrast resolution,low contrast resolution detectivity and positional accuracy of diagnostic couch were all reached to 100%. The qualified rate of locating light accuracy,reconstruction depth of stratum,CT value of water and homogeneity were all 98. 6%. The qualified rate of CT dose index was 97. 1%,the qualified rate of noise was 81. 4% and the qualified rate of CT linear value was 68. 6%. There were only 28 CT machine totally meet with the national standards. The radiation level were all below 2. 5μSv·h- 1,all meeting with national standards. Conclusion The qualified rate of key indexes of CT are relatively high,with the qualified rate of noise and linear are relatively low.The quality control of CT machine should be strengthened and stability test and maintenance need to be routinely carried out to ensure the well performance of CT machine. The CT room all meet with the national standards.