Local diagnostic reference levels for adult posteroanterior (PA) chest x-ray examination in Addis Ababa, Ethiopia.

BACKGROUND The Local Diagnostic Reference Levels (LDRLs) form an efficient, concise and powerful standard for optimizing the radiation protection of a patient. OBJECTIVES To calculate the Entrance Surface Doses (ESDs) received by patients undergoing PA chest X-ray examinations in major public hospitals in Addis Ababa, thereby to establish the first Ethiopian LDRLs as part of ongoing dose reduction program. MATERIALS AND METHODS The entrance dose in air per examination was measured in eight hospitals comprising nine X-ray units and a sample of 192 radiographs. The entrance dose in air was measured using dositime dx X-ray Digital Dosimeter and Exposure Time Meter. The data were analyzedstatistically, and the minimum, median, mean, maximum, and third quartile values of ESDs are reported Finally, the proposed LDRLs are compared with the international reference dose values reported by the Commission for European Community (CEC), the International Atomic Energy Agency (IAEA) and the National Radiological Protection Board (NRPB). RESULTS The third quartile value of the distribution of mean doses at individual hospitals participating in this survey is found to be 1.08 milligray (mGy). Hospitals mean ESDs for PA chest X-ray examination is found with the range of 0.0.76 to 1.48 mGy. Most of the ESD measured doses were slightly greater than the NRPB, CEC and IAEA reference doses. CONCLUSION The results of the present study indicate a need for Quality Assurance (QA) programs to be undertaken to avert considerable cost and high patient doses. The results are useful to national and professional organizations and can be used as a baseline upon which future dose measurements may be compared.