Radiation dose optimisation in diagnostic radiology requires continuous quality control (QC) test of the facilities to ensure that they perform optimally. In this study, quality control test of X-ray machines in selected University Teaching Hospitals in Nigeria was performed. Reproducibility of dose output, time and tube voltage were assessed using calibrated QC kV meter (NEROTM 6000m, manufactured by Victoreen, INC. Cleveland, Ohio, USA). The results of kVp accuracy (in %) were 0.35, 0.96, 0.84 and 0.52 for Ladoke Akintola University Teaching Hospital Osogbo (LTH), Obafemi Awolowo University Teaching Complex Wesley Guild Ilesa (OAUTHC), University Teaching Hospital Ado–Ekiti (UTH) and University of Benin Teaching Hospital Benin City (UBTH) respectively and the variance of kVp reproducibility ranged from 0.14% in LTH to 0.48% in OAUTHC. The exposure time accuracy ranged from 0.3% in LTH to 0.96% in UBTH and output linearity ranged from 0.04 to 0.09% in UTH and OAUTHC respectively. The results obtained were compared with the acceptable standard tolerance limits set by American Association of Physicists in Medicine (AAPM). Some of the results were found to be in good agreement with the standard tolerance limits adapted in this study.
Keywords: Radiation dose optimisation, quality control test, kVp reproducibility, exposure time accuracy, output linearity.