Diagnostic reference levels in the X–ray department

Abstract

This article reviews developments in Europe over the past 10 years in the radiation protection of patients undergoing medical X-ray examinations that led to the requirement in the EC Medical Exposure Directive of 1997 that all Member States should establish Diagnostic Reference Levels (DRLs). The purpose of DRLs is explained and methods for deriving national DRLs that comply with the requirements of the Directive are described. Suitable patient dose quantities are defined and dose measurement methods and patient sampling techniques that can be used both by the appropriate authorities for setting national DRLs, and by individual X-ray departments for checking compliance with them, are discussed. Finally, the progress made over the past 5 years in translating the requirements of the Directive into national legislation, including the provision of guidance on the use of DRLs for X-ray departments, is reviewed. It relies heavily on the author’s experience of how these matters are progressing in the UK, but will hopefully be of some practical help to the staff in X-ray departments from all over Europe.