2003年全国調査によるX線診断時の患者被ばく線量

抄録

We have reported on changes in the doses of medicalradiation exposure in Japan. The first investigation was made in 1973. The investigation made in 2003 was the 7th. The investigation was made at 15 regions in 21 directions. The investigation items consisted of generating systems, irradiation conditions, kinds of film screen system and total filtration. While the dose varies with each region, it decreased in the 2001 investigation compared with that in 1997 and tended to increase slightly according to the 2003 investigation. In chest X-ray examination, an increase in dose was seen, and the dose was increased compared with that in 2001 ; it was 96% almost the same as the data of 30 years ago in 1973. At other regions except the chest examination, the dose was less than 1/2 the dose of 30 years ago. With the examination of the breast, the dose was decreased markedly at 6%. The image output has been changed from the film screen system (F/S) to the digital radiography (DR). The proportion of DR used was 15% in 1997, 50%in 2001 and 70% in 2003. The dose by DR was slightly increased compared with that by F/S.