全数字化乳腺X射线摄影系统质量控制检测方法探讨

目的:对全数字化乳腺X射线摄影系统的主要参数进行质量控制检测,以保证设备性能良好。方法:采用瑞典奥利科Piranha型乳腺机剂量仪、M12乳腺X射线机性能检测模体对全数字化乳腺X射线摄影系统进行胸壁侧照射野准直、光野与照射野的一致性、管电压指示的偏离、半值层、自动曝光控制重复性、探测器均匀性、伪影、高对比分辨力和乳腺平均剂量等检测。检测完毕根据测算方法计算出检测结果,并判断其是否符合WS 522-2017《乳腺数字X射线摄影系统质量控制检测规范》要求。结果:胸壁侧照射野准直检测中硬币被切割的直径距离为4 mm;光野与照射野的一致性检测中光野与照射野相应边沿的偏差为5 mm;管电压指示的偏离最大值为0.31 kV;靶/滤过为Mo/Mo,半值层为0.34 mmAl;自动曝光控制重复性的偏差为2.6%;探测器均匀性检测中图像中心区域与边缘区域兴趣区像素值的偏差为1.60%;无影响临床影像的伪影;高对比分辨力纵向为8 lp/mm,横向为10 lp/mm;乳腺平均剂量为0.61 mGy。全数字化乳腺X射线摄影系统符合WS 522-2017《乳腺数字X射线摄影系统质量控制检测规范》要求,质量控制检测通过,设备运行良好。结论:通过对进行质量控制检测,可以客观地反映设备的性能,从而保证设备处于良好的运行状态。

Study on full field digital mammography system quality control test

Objective To carry out quality control test of full field digital mammography system to ensure its performances.Methods Full field digital mammography system was tested with Piranha dosimeter and M12 phantom on radiation field collimation at chest wall edge,consistency between light field and radiation field,deviation of tube voltage indication,half value layer,repeatability of automatic exposure control,detector uniformity,artifact,high-contrast resolution,mean dose of breast and etc.The results were calculated after detection,and then were verified whether they accorded with WS 522-2017 Specification for testing of quality control in digital mammography systems.Results The diameter distance of coin cut was 4 mm in the detection of radiation field collimation at chest wall edge;the deviation between light field and corresponding edge of radiation field was 5 mm in the consistency test for light field and radiation field;the maximum deviation of tube voltage indication was 0.31 kV;target/filter was Mo/Mo,and half value layer was 0.34 mmAl;the repeatability deviation of automatic exposure control was 2.6%;the deviation of pixel value between the center area and the edge area of interest in the detector uniformity detection was 1.60%;there was no artifact affecting the clinical image;the high contrast resolution was 8 lp/mm in the longitudinal direction and 10 lp/mm in the transverse direction;the mean dose of breast was 0.61 mGy.The results accorded with WS 522-2017 Specification for testing of quality control in digital mammography systems,and thus the full field digital mammography system proved its performances.Conclusion Quality control test of the full field digital mammography system contributes to keeping it in a good running condition.