Film retakes in digital and conventional radiography

ABSTRACT

To determine the film-retake rates and causes in digital radiography comparison to conventional X-rays method. Comparative study. Radiology Department, Aga Khan University Hospital, Karachi, from January 2004 to December 2006. X-rays of different body parts, conducted during the year 2004, with conventional radiography [n=170300], and in 2006 with digital radiography [n=174550], were included in this study. Measurements were done for number of X-rays re-take due to different quality control reasons for both the conventional and digital radiography. Quality control reasons included underexposure, overexposure, positioning errors, patient movements, portable X-rays, grid cut-off, and others [i.e. equipment related] due to which X-ray quality was questionable. Results were expressed in percentages. A total of 9423 X-rays [5.5%] were repeated in conventional radiography [n=170300] due to underexposure [38%], overexposure [28.5%], positioning errors [25%], portable procedures [4%], patient movement [2%], grid cut-off [0.5%], and others [2%]. Underexposure was the most frequently responsible factor for the X-ray repetition as compared to other factors [p<0.001]. In digital radiography [n=174550], 1464 X-rays [1%] needed to be repeated, which was significantly less in comparison to X-ray repetition in conventional method of radiography [5.5%] [p<0.001]. In digital radiography, the most frequent factor for X-ray re-take was positioning error [435, 30%]. Digital radiography is associated with significantly lesser number of re-take X-rays as compared to conventional radiography, hence minimizes the exposure of the patients to unnecessary radiations due to re-take X-rays. Positioning error remains a problem even in digital radiography, emphasizing training need for technologists