Study on patient dose in diagnostic radiology in Japan: Investigation of entrance surface dose of patient using direct measurement by TLD

This study was conducted to research radiation exposures by routine X-ray examinations in the hospitals to establish the guidance level in Japan. So a multicenter study was carried out to evaluate radiation doses in routine radiographic examinations. In this study, we investigated entrance surface doses of patients using direct measurement by TLD for 5 various types of radiography: Chest PA, Abdomen AP, Lumber spine AP, Lumber spine LAT and Pelvis AP. From the results, we examine the (a) need for introducing the guidance level in Japan, (b) controversial points in the calculation method for patient dose evaluation, (c) evaluation accuracy required for introducing the guidance level, and (d) necessity for a standardized method for patient dose evaluation. (author)