Evaluation of kilovoltage failure in conventional X-ray machines among selected X-ray Centers in Jos North Local government area of Plateau State, Nigeria

Abstract

Background: The goal of quality assurance of x-ray machine is to obtain accurate and timely diagnosis and low dose to patients. Aims and Objectives: To determine peak kilovoltage (kVp) accuracy and reproducibility of 23 individual X-ray machine and compare their values with recommended standards. Materials and Methods: Measurements were taken in the 23 diagnostic centers (XRY 1 – XRY 23 ). Unfors Thinx RAD detector which served as the mimicked patient was placed at Source to Image Distance (SID) of 100 cm. At a constant tube current, several kVp values were used for both the accuracy and reproducibility test. Any results above ±5% were termed “Not Acceptable”. Data analysis value was done using GraphPad Prism version 5.0 statistics software. Results: A total of 16 X-ray machine passed the kVp accuracy test (69.57%) while 7 X-ray machine failed the test (30.43%). Also, 15 X-ray machine passed the kVp reproducibility test (65.22%), while 8 X-ray machine failed the test (34.78%).There was no correlation (P = 0.916) between kVp accuracy and reproducibility test also no significant difference (P = 0.5134). Very good statistical significant difference was seen between the machine age, kVp accuracy and reproducibility respectively (P<0.05) Conclusion: This study has shown that more than one third of the total X-ray machines failed both kVp accuracy and reproducibility test. There are strong indications that machine age had significant effect on kVp accuracy and reproducibility. Keywords: Peak kilovoltage, Radiation dose, X-ray, Unfors Thinx RAD detector, Milliampere seconds