An Evaluation of Entrance and Surface Doses for some Common Diagnostic X-ray Examinations in two Nigerian University Teaching Hospitals

Background: The aims of this study were to estimate Entrance Surface Dose (ESDs) to patients undergoing selected diagnostic X-ray examinations in two Nigerian university teaching hospitals, to obtain the maximum to minimum ratio of ESDs for the same projections, and to compare the ESD obtained with established international reference doses. Methods: The exposure parameters such as the tube potential (kVp), the tube current (mAs), focus-to-film distance (FFD) and the thickness of the area irradiated were obtained for each patient undergoing the specified diagnostic procedure and the entrance surface doses were estimated. Results: Hospital mean ESD estimates ranged from 0.099 to 0.3mGy for chest PA; 0.4 mGy for chest LAT; 1.1 2.9mGy for pelvis/hip AP; 0.9 2-8mGy for skull AP/PA; 0.4-1.7mGy for skull LAT; 1.7-1.8 mGy for Abdomen AP; 1.7-4.1 mGy for lumbar spine AP; 3.95.8mGy for lumbar spine LAT; 0.1-0.3mGy for Extremities AP and 0.1--0.3 mGy for Extremities LAT. Conclusions: In the two hospitals, mean ESDS were found to be within the established international reference doses.