江苏省乳腺X射线摄影医疗照射剂量调查

目的］ 通过调查和测量计算江苏省乳腺X射线摄影受检者乳房压缩厚度（compressed breast thickness，CBT）和腺体平均剂量（average glandular dose，AGD），了解江苏省乳腺X射线摄影的AGD分布情况及影响因素。 ［方法］ 抽样调查来自5 城市17 个医疗机构中17 台次340 个乳腺X射线摄影的曝光参数，使用X线质量控制检测仪测量其入射体表空气比释动能（entrance surface air kerma，ESAK）。使用国际通用方法计算AGD，并分析其与CBT等因素的关系。［结果］ 在江苏省抽取的340 个乳腺X射线摄影参数中，AGD均数为1.66 mGy。CBT 服从正态分布，均数和标准差分别为4.22 cm和1.12 cm。两种不同体位的CBT 差异有统计学意义（t=-3.481，P 〈 0.05），两种体位的AGD水平差异无统计学意义（t=-0.791，P 〉 0.05）。 ［结论］ CBT 可能通过不同机制影响AGD水平，可为建立适合我国乳腺X射线摄影受检者剂量指导水平提供依据。

Average Glandular Dose in X-ray Mammography in Jiangsu Province,China

Objective] To estimate the distribution of average glandular dose （AGD） level in X-ray mammography in Jiangsu Province by the measurement of AGD and compressed breast thickness （CBT）. Methods] A survey on 340 mammography exposures recorded in 17 mammography machines from 17 medical facilities in 5 cities was conducted, and the exposure parameters were retrieved. Entrance skin air kerma （ESAK） was measured according to the exposure records, and AGD was calculated using the Dance’s formula. AGD-CBT relationship was then analyzed. Results] The mean value of AGD in the collected 340 mammography parameters was 1.656 mGy, and the mean value and the standard deviation of CBT were 4.22 cm and 1.118 cm respectively. No significant difference in the AGD data was found between the two postures groups, but significant difference existed in the CBT data. Conclusion] Varied mechanisms may be involved in the changes of AGD level caused by CBT. The further study can provide evidence for establishing a guideline of AGD in mammography receiver in China.