ASSESSMENT OF KILOVOLTAGE PEAK (kVp) ACCURACY AND REPRODUCIBILITY TEST OF X-RAY MACHINES AS QUALITY ASSURANCE MEASURES IN ABUJA HOSPITALS, NIGERIA

Abstract

Background: Conventional radiography practices using X-rays have been a crucial radio-diagnostic tool for detecting internal organ ailments, malformations and disease conditions in humans and animals for many years. However, these practices are not without its challenges; overexposure to ionizing radiation due to machine factors is often neglected. Patients are often subjected to multiple X-ray examinations as their initial radiographs are rejected due to poor image quality, which can be because of overexposure or under exposure to the ionizing radiation. Objective: This study was performed to evaluate the accuracy and reproducibility of kVp in X-ray machines installed in selected hospitals in Abuja as a measure to ensuring that the radiation doses selected are the ones delivered to patients. Methodology: Data was obtained from FEZIKA LOGISTICS LTD, a company licensed by Nigeria Nuclear Regulatory Authority (NNRA) to conduct quality control (QC) test and provide Radiation Safety Advisory Services for Hospitals, Industries,andOilandGasCompanies. Atotaloffivehospitalswereselected from the list of clients serviced by FEZIKA LOGISTICS LTD for this investigation. A Cobia Smart R/F semiconductor detector (model- CB3- 19098461) calibrated to measure tube potential within the range of 50kV to 200kV was used. The detector was positioned at the center of the table, and the central ray of the X-ray beam was directed towards the meter, utilizing a focus- to-film distance (FFD) of 100cm. Values for kVp accuracy and Reproducibility were taken at different points and readings were obtained using calibrated kVp meter. Results: The result for kVp accuracy for machines XM-1, XM-2, XM-3, XM-4 and XM-5 shows average percentage error of 1.83%, 1.83%, 2.03%, 3.03%, 1.29% and 2.40% respectively which are within the tolerance limit of ±5 % while the kVp reproducibility of the machines XM-1, XM-2, XM-3, XM-4 and XM-5 exhibit values of 0.39%, 0.32%, 1.64%, 0.10% and 0.07% respectively and these are also within the normal limit of tolerance of less than ±5%. Conclusion: The results for kVp accuracy and reproducibility for the machines used for medical diagnosis in the hospitals in Abuja investigated were within normal limits.