Optimizing patient doses in radiographic examinations in the DRC: Preliminary results

The aim of these investigations was to survey the quality of the radiographic images and the entrance air kerma (ESAK) to patients exposed to simple radiographic examinations and to perform comparisons with diagnostic reference levels (DRLs). Based on the working material provided by the IAEA under the framework of the Project RAF/9/033, in the form of a standardized questionnaire, image quality and patient dose levels were surveyed in 5 radiology departments in the city of Kinshasa. Film reject rate and film quality grading were carried out and causes for poor image quality investigated. Using x-ray tube output measurements and x-ray exposure parameters, the entrance surface doses to adult patients were determined in terms of ESAK. The resulting dose levels were compared with DRLs as an approach to the optimization and the potential for dose reduction. Poor quality images ranged 27% - 67% before implementation of QC tests. The image quality improvement up to 17% was achieved. Doses to Patients were below DRLs and varied by a factor of up to 8.2. The mean ESAK ranged 0.4 - 2.5 mGy (Chest PA), 2.5 - 9.5 mGy (Pelvis AP), 3 - 10.7 mGy (Lumbar Spine AP), and 2.6 - 9.6 mGy Abdomen AP) and. Reductions in Patient dose up to 47% were achieved. The patient doses are higher than doses in most countries participating to the Project although important reductions were recorded. Implementing QA programmes on a regular basis and specific training programme in medical imaging could increase the awareness on the quality of radiographic images and serve as an optimization tool. (author)