X-RAY DOSE AUDIT AND POTENTIAL LOCAL DIAGNOSTIC REFERENCE LEVELS IN SELECT HOSPITALS IN KADUNA STATE, NIGERIA

Background: Dosimetry in diagnostic radiology is fundamental to providing information to practitioners regarding the level of their doses and to ensure adequate optimization of the protection of patients presenting for radiological examinations. The introduction and implementation of diagnostic reference levels (DRLs) in diagnostic radiology has proven to be a potent tool for quality control and dose reduction. This has not been comprehensively addressed in Nigeria. Objective: To carryout dose audit of patients presenting for common radiographic projections in select hospitals in Kaduna State, Nigeria. Methodology: Thermoluminescent dosimeters (TLDs) were used to measure entrance surface dose (ESD) on 420 randomly selected adult patients presenting for x-ray examination of the chest PA/Lateral, skull PA/Lateral, lumbar spine AP/Lateral, abdomen and pelvic AP, respectively. Results were compared with existing literature. Results: The range of the mean ESD determined for the study population on various x-ray examinations were: chest PA (0.44 – 0.9 mGy), and lateral (0.9 – 1.5 mGy); skull PA (2.0 – 4.7 mGy), and lateral (1.7 – 3.4 mGy); lumbar spine AP (3.4 -7.8 mGy), and lateral (6.8 –11.3 mGy); abdomen AP (3.6 – 6.2 mGy); and pelvic AP (2.4 – 6.9 mGy). Comparison showed dose levels were below IAEA recommendations. Conclusion: In the absence of arbitrary high doses, practice is generally safe and will not result in unwarranted hazards to the patients.