Clinical performance of a prototype flat panel digital detector for general radiography

Digital radiographs obtained using a prototype Digital Radiography System (Stingray) were compared with those obtained using conventional screen-film. Forty adult volunteers each had two identical radiographs taken at the same level of radiation exposure, one using screen-film and the other the digital detector. Each digital image was processed by hand to ensure that the printed quality was optimal. Ten radiologists compared the diagnostic image quality of the digital images with the corresponding film radiographs using a seven point ranking scheme. For 27 non-chest examinations, digital images were slightly inferior to screen-film for bone detail (p < 0.001) and bone contrast (p < 0.001), but were slightly superior to those of screen-film for soft tissue contrast (p < 0.001). For 13 chest examinations, the digital detector images were slightly inferior to screen-film for visualizing the mediastinum (p < 0.001) and the spine (p < 0.001), but were not significantly different to those of screen-film for visualizing the lung or ribs. Perceived mottle on digital detector images was lower than that on screen-film images (p < 0.001). The digital detector was inferior to screen-film for overall image quality (p < 0.001), but differences in image quality were smaller than inter-reader variability, and would not justify additional patient radiation exposure or radiologist time to additionally process the images.