[Dose estimation for exposure conditions of diagnostic radiology acquired by a 2011 questionnaire in a phantom study]

Using a 2011 questionnaire, the Japanese Society of Radiological Technology conducted a nationwide survey on the exposure conditions in diagnostic radiography. The purpose of this study was to measure the entrance surface dose and absorbed dose for each organ dose and to calculate the effective dose using a human phantom with the 2011 exposure conditions. We estimated the patient exposure doses during skull (antero-posterior), chest (postero-anterior), abdomen (antero-posterior), and lumbar vertebrae (antero-posterior, left-right, and right-left) radiographs. The radiation doses were determined by placing 255 thermoluminescence dosimeters at various positions on and in the phantom, including the surface of the skin, head, thyroid, lung, breast, esophagus, stomach, liver, and gonads. The maximum entrance surface dose was 7.83 mGy, which occurred to the lateral lumbar spine. In addition, the minimum entrance surface dose was 0.24 mGy, to the chest. The maximum organ dose was 3.15 mGy, to the stomach of the lateral lumbar vertebrae (LR). Meanwhile, the maximum effective dose was 0.63 mSv, to the lateral lumbar vertebrae (LR). On the contrary, the minimum effective dose was 0.03 mSv, to the head. We could evaluate the entrance surface dose, absorbed dose for each organ dose, and effective doses using the 2011 exposure conditions in Japan. The entrance surface dose of 5 examinations with these exposure conditions was below the guidance level of the IAEA. In the future, it can be said that the entrance surface dose as well as the effective dose require diagnostic reference levels in radiography.