Objective To understand the level of radiation doses from digital mammography in Tianjin and the associated influencing factors.Methods The stratified quota sampling method was used for analysis of 374 digital mammography-examined individuals by using 12 digital mammography devices in 12 selected medical institutions.The examinations were carried out in terms of exposure positions[(craniocaudal(CC)and mediolateral oblique(MLO)],compressed breast thickness,tube voltage,time product of tube current(mAs)and target/filter.Results The median age of the examined individuals in this survey was 43 years,the median tube voltage(kV)was 29 kV,the median tube current time product was 60.3 mAs,the median compressed breast thickness was 48 mm,and the median average glandular dose(AGD)was 1.32 mGy.The mean dose to the analyzed glandular tissue in the conditions of different target/filters varies in the descent order of Mo/Mo＞Mo/Rh＞Rh/Rh＞W/Rh＞W/Al,with the difference being statistically significant difference(x2=885.90,P＜0.05).The mean dose to the glandular tissue increased with the increase in compressed breast thickness,and the difference was statistically significant(x2=31.58,8.56,76.13,118.47,24.09,P＜0.05).Conclusions The median average glandular dose in Tianjin was 1.32 mGy.This level is lower than in Guangxi province and Fuzhou city,similar to that in Beijing and Guangdong province,and lower than the national survey result of average breast dose.The efforts should be dedicated to further strengthening the research on the related factors of the average glandular dose in order to protect the health and safety of the examined individuals.
关键词
数字化乳腺X射线摄影/乳腺平均剂量/调查
Key words
Digital mammography/Average glandular dose/Investigation
万方数据