Patient dose assessment in Computed Tomography in a Moroccan imaging department

Abstract

Facing the inflation of the number of irradiating radiological examinations, particularly in Computed Tomography (CT), several countries in the world have resorted to diagnostic reference levels (DRLs), below which dosimetric values must be kept or else corrective actions will be infligated. In Morocco, in the absence of national diagnostic reference levels, we proposed to evaluate the professional practice in CT by recording the radiation doses values delivered to adult patients and comparing the 75th percentile values of the dosimetric indicators (CTDIvol and DLP) per acquisition to the international published values of DRLs, in order to judge the need for optimization of CT examination protocols. The 75th percentile values in terms of CTDIvol for head, chest, abdomen-pelvis, chest- abdomen-pelvis, and lumbar examinations were respectively 57.7, 11.1, 11.3, 11.6 and 20 mGy. In terms of DLP, the 75th percentile values were 1250.4, 392.2, 517.1, 833.27 and 707.37 mGy.cm, for the mentioned type of examinations. These results prompt us to make corrections to the used protocols and to ensure a more rigorous follow-up of the radiation protection principles with particular attention to the principle of dose optimization in order to establish a good practice in CT.