Quality control assessment of diagnostic X-ray facilities in Ghana

Abstract

Twenty-three X-ray machines located at 20 different hospitals in Ghana were assessed for quality assurance and control. The radiographic parameters evaluated were tube voltage and current, tube output consistency variation with kilovoltage (kV) and current-time (mAs) factor, exposure time accuracy and beam quality as measured by half-value layer. The photographic parameters assessed were type of films, level of film fogging, film speed, contrast index and film processing temperature. Twenty two of the machines were ~ 99 % output consistency with standard kVp and mAs. Twelve of the machines had output linearity deviation of less than the acceptable 5 %, while 22 machines were within the accepted kVp deviation of 5 %. The film processing temperature at most hospitals exceeded the required level, due to the absence of air conditioners in the darkrooms. The darkroom quality control at all the facilities was very high. Fogging of films was minimal as indicated by the Base + Fog value of 0.3, speed index of film was ~ 1.65 and contrast index was comparable to the acceptable value of 1.5. The level of timer accuracy was greater than 95 % for all the X-ray machines with the exception of one. The general quality control status of all the X-ray machines and darkrooms assessed were acceptable and within the quality assurance standards.