Radiation Exposure by Routine Radiographic Examinations: Multicenter Study in Japan with Thermoluminescence Dosimetry and Estimation from the Radiographic Data

INTRODUCTION X-ray examinations are commonly used in health care and, in most developed countries, they represent the largest man-made source of radiation exposure for the population. The need for standardization of radiation exposures has been suggested and the guidance levels for various radiographic and radioisotope examinations has been proposed by the International Atomic Energy Agency (IAEA) as a Safety Standard (1). The guidance levels by IAEA are based on European studies (2-4). In many countries, the situation of medical radiographic exposures in each country should be researched before the appropriate guidance level is established. This study was conducted to research radiation exposures by routine x-ray examinations in the major hospitals in Japan. Five types of simple radiography were selected on the basis of their prevalence in the clinical medical practice; the posteroanterior (PA) chest, anteroposterior (AP) abdomen, AP pelvis, and AP and lateral (LAT) lumbar spine. The radiation dose was estimated by a calculation method based on the radiographic data. In a limited number of hospitals, thermoluminescent dosimeters (TLDs) were also used to measure the entrance surface dose of the patients and compared with the results from the calculation method.