Survey of patient exposure from general radiography and mammography in Japan in 2014

With the objective of reducing patient exposure to radiation, we conducted a questionnaire survey regarding radiographic conditions in 2014. Here we report estimates of dose exposure in general radiography and mammography through an investigation and comparison of present patient exposure conditions. Questionnaires were sent to 3000 facilities nationwide in Japan. Surveys asked questions on a total of 16 items related to general radiography, including the chest, abdomen, and breast. Output data from x-ray tubes measured in the Chubu area of Japan were used as the mean in these estimates. The index of patient exposure was adopted as the entrance skin dose (ESD) for general radiography and as the mean glandular dose (MGD) for mammography. The response rate for this survey was 21.9%. Our results showed that doses received through the use of flat-panel detector (FPD) devices were lower than those received through computed radiography devices, except for the ankle joint (e.g. in chest examination, the dose from FPD and CR was 0.24 mGy, 0.31 mGy on the average, respectively). These results suggest that more widespread use of FPD devices could lead to decreases in the ESD and MGD, thereby reducing patient exposure.