Studies on optimization of radiation protection for patients in diagnostic radiology

For the exposure of patients in diagnostic radiology, individual dose limit does not apply, but optimization of radiological protection may play a major role. This project has been carried out with the purpose of improving the protection of patients in medical diagnostic radiology in China utilizing the principles of optimization. Taking Sichuan, Shandong and Beijing as surveyed areas, we investigated the present situation of the protection of patients. In the survey, the patient doses were classified into practical dose, justified dose and optimized dose to evaluate the influences of managerial and equipment factors separately. The results show that there are some urgent protection problems in X-ray protection to be solved in the surveyed regions. This paper, however, points out that the prospects of reducing patient doses are encouraging provided that appropriate measures are adopted. For instance, taking proper managerial measures without radical change of existing equipments may reduce patient doses in chest fluoroscopy and radiography by 40% and 18% respectively ; refitting some equipment may reduce the doses by 82.4% in chest fluoroscospy, 66% in chest radiography, and 80% in barium meal examination of the gastrointestinal (GI ) tract. Using chest radiography instead of fluoroscopy supplemented by other protection measures may reduce the doses by 91.7%. Optimization analysis shows that adoption of the above measures conforms to the principle of optimization of radiation protection. RÉSUMÉ Si, dans le cas du radiodiagnostic, les limites de dose individuelles ne s'appliquent pas à l'exposition des patients, l'optimisation de la radioprotection peut, par contre, jouer un rôle important. L'utilisation du principe d'optimisation a guidé ce projet visant à améliorer, en Chine, la protection des patients lors de la pratique du radiodiagnostic médical. Notre enquête, réalisée dans les régions de Sichuan, Shandong et Pékin (Chine), a évalué la situation actuelle de la protection des patients. Les doses aux patients ont été classées en dose réelle, dose justifiée et dose optimisée afin d'évaluer séparément l'influence des facteurs de * Laboratory of industrial hygiene, Ministry of public health, 2 Xinkang street, PO Box 8018, Beijing 100088, P.R. China. ** Institute of radiation medicine, Shandong Academy of medical sciences, Jinan 250001, P.R. China. *** Sichuan Institute of radiation health protection, Chengdu 610041, P.R. China. **** Beijing Institute of radiation health protection, Beijing 100013, P.R. China. RADIOPROTECTION VOL. 29 0033-8451/1994/11/$ 5.00/© Les Editions de Physique 201