[en] This document sets out to record and analyze the doses incurred in Canada from medical procedures involving the use of ionizing radiation in a typical year. Excluded are those doses incurred during therapeutic irradiation, since they differ in scale to such a large degree and because they are used almost exclusively in treating cancer. In this we are following a precedent set by the United Nations Scientific Committee on the Effects of Ionizing Radiation. Although the International Commission on Radiological Protection (ICRP) notes that dose limits should not be applied to medical exposures, it also observes that doses in different settings for the same procedure may vary by as much as two orders of magnitude, and that there are considerable opportunities for dose reductions in diagnostic radiology. Because these data do not stand in isolation the report also encompasses a review of the relevant literature and some background comment on the evolving technology of the radiological sciences. Because there is a somewhat incomplete perception of the changes taking place in diagnostic methods we have also provided some introductory explanations of the relevant technologies. In addition, there is an analysis of at least some of the limitations on the completeness of the data which are reported here. (author)