X-ray image reject analysis in digital radiography at the Radiology Department Block F, Mulago National Referral Hospital

Abstract

Introduction: The number of rejected images is an indicator of poor image quality and unnecessary imaging at radiology department. Image reject analysis was frequent in the film era, but comparably few and small studies have been published after converting to digital radiography. Main objective: The aim of this study was to assess the rate of X-ray image reject in direct digital radiography (DR) at the radiology department block F of new Mulago National Referral hospital. Methods: A prospective study design was used, employing quantitative methods of data collection at the radiology department block F of Mulago national referral hospital located in Kampala, central part of Uganda. The data were collected by reject analysis software embedded within the X-ray unit. Reject rates, and reasons for rejection for each X-ray projection were analyzed. Results: Out of the 2134 acquired images, 238 were rejected, yielding an overall Rejection Rate of 11.2%. Highest Rejection Rates were found for examination of Mandible(22%), Thoracic spine(22%), lumbosacral spine (19%), and shoulder(19%). The projections with the highest rejection rate, include the additional projections other than the routine anterior-posterior(AP) and lateral of the cervical spine(50%), pelvis(42%), shoulder(32%), mandible(31%) and lumber spine(30%). Positioning errors (44%) and anatomic cutoff (25%) were the main reasons for digital image rejection. Conclusions: The findings of this study indicate a significant rate of image rejection of 11.2% in digital radiography. It has been established that poor image quality produced by the X-ray department unit results in inadequate information on anatomical site pathology for radiologists to interpret results of the examination. Recommendations: It is recommended that, a review of rejected films should be made on periodic basis as part of the overall quality assurance program of the hospital in order to identify the magnitude of the problem and also to determine the causes.