Assessment of secondary radiation dose in radiology departments

Abstract

BackgroundIn hospitals and clinics, medical imaging using ionizing radiation is one of the most essential and powerful diagnostic techniques that exposes patients, workers, and the general population to radiation through primary and secondary radiation. Thus, routine leakage testing of X-ray tubes and scattered radiation testing are important in ensuring the absence of leakage and scattered radiation. Materials and methodsThis investigation conducted background and secondary radiation exposure assessments of 17 X-ray units in the radiology departments of three selected major public hospitals. The weekly dose in both controlled and uncontrolled areas was measured using a Ludlum Model 9DP-1 ionization chamber dosimeter and expressed in μSv/h. Resultsand Discussion: The highest dose was recorded in the controlled area of the CT scan room in Hospital A, where the mean dose rate was 12.16 μSv/h (in the control door) and 8.38 μSv/h (in the main door). The dose rates in these areas were approximately ten times higher than those measured in corridors. Generally, the measurement results showed that the scattered radiation doses in the controlled and uncontrolled areas of the radiology units were within the permissible limits set in the National Council on Radiation Protection & Measurements Report No. 147. This finding may be attributed to the distance between these locations and the X-ray sources, and the lead lining of the area. ConclusionThe secondary radiation levels in the assessed diagnostic rooms were within the reference exposure level for the public and workers, indicating that appropriate barriers (doors and walls) had been installed in the investigated hospitals.