Quality Control and Diagnostic Image Integrity In Radiography; an Evaluation of Some Selected Diagnostic Centers In Zaria Nigeria

Abstract

Maintaining optimal image quality and radiation safety in diagnostic radiography relies heavily on regular quality control (QC) testing of radiographic equipment. However, in many developing regions, QC practices are inconsistent and often poorly documented.This study evaluated the adequacy and compliance of QC testing in diagnostic radiography units across selected public hospitals in Zaria, identifying deviations from standard regulatory requirement and highlight areas needing improvement.A cross-sectional descriptive study was conducted in radiology departments of public hospital in Zaria, Nigeria. Standard QC parameters including exposure reproducibility, kVp accuracy, half value layer (HVL) and beam alignment and collimation were evaluated using established QC kit.Two of the three machines (M2 and M3) performed within acceptable international standards, while one machine (M1) showed significant deviations. The kVp accuracy test revealed a mean percentage error of 27.62%, 2.41%, and 4.16%for M1, M2, and M3 respectively. Exposure reproducibility tests showed coefficient of variation values of 5.93%, 3.25%, and 4.37%. HVL values were 1.55 mmAl(M1), 3.0 mmAl(M2), and 2.9 mmAl(M3), indicating insufficient filtration in M1. Beam alignment and collimation results for M2 and M3 were within +1% and ±2% tolerance, respectively. Due to M1’s instability, the full collimation test could not be completed. Machine M2 and M3 met QC standards, while M1 failed most tests, reflecting possible calibration or maintenance are recommended to ensure optimal equipment performance and minimize unnecessary radiation exposure.