Quality control assessment and establishment of local diagnostic reference levels in two radiological centres in Osogbo, Nigeria

This study aims to assess Quality Control (QC) tests, determine the Entrance Surface Dose (ESD), and establish Local Diagnostic Reference Levels (LDRLs) for patients undergoing X-ray examinations at the University of Osun Teaching Hospital (UniOsun) and Union Diagnostic Centre (UDC), Osogbo, Nigeria. Demographic data from 334 patients, along with exposure parameters (kVp, mAs, FFD, and FSD), were recorded using a specially designed questionnaire with the assistance of radiographers. A one-time QC assessment test was conducted to verify the compliance of the X-ray machine with the international standard using a Gammex 330 Digital kV, dose, and time meter obtained from the National Institute for Radiation Protection and Research at the University of Ibadan, Nigeria. As referenced in the literature, a mathematical model was used to calculate the ESD (mGy) for various X-ray examinations conducted at UniOsun and UDC. Statistical analysis of the results was performed, and the 75th percentile for ESD was calculated. The results indicated that the mean highest ESD belonged to the Skull (0.047 ± 0.001) mGy and Lumbar spine (1.76 ± 0.48) mGy, and the lowest ESD belonged to the Elbow (0.012 ± 0.002) mGy and Elbow, Hand, Wrist (0.39 ± 0.06) mGy for UniOsun and UDC, respectively. The LDRL of the ESD ranged from (0.014-0.048) mGy to (0.42-2.29) mGy at UniOsun and UDC, respectively. In conclusion, the findings revealed a significant variation in ESD across different examinations and centres, highlighting the necessity for tailored dose optimisation strategies to ensure patient safety while maintaining diagnostic quality.