Radiation dose in imaging of coronary artery disease: current status and perspectives

calculations, since there is no directly measur­ able quantity that adequately reflects radiation exposure [1,2]. Nevertheless, the most adequate approach to describe risks associated with ion­ izing radiation is to describe it in terms of dose. Adding up the weighted equivalent doses of all organs, the effective dose (E) is computed. Since it is a single number, E – which is measured in mSv – has become the most frequently used quantity to compare the radiation risks of differ­ ent diagnostic tests. Nevertheless, the effective dose must be applied with caution: its applica­ tion is defined for populations, not for the esti­ mation of radiation dose for one examination on one single patient. Accordingly, it is, in itself, not ideally suited to describe the individual esti­ mated cancer risk attributed to an examination using ionizing radiation, as it is always subject to uncertainty [3,4].