A comparison of image reject rates when using film, hard copy computed radiography and soft copy images on picture archiving and communication systems (PACS) workstations.

A comparison has been made of the reject rates of plain images for three separate periods when film, computed radiography (CR) and PACS systems were in operation throughout the Hammersmith Hospital, London. There was a statistically significant reduction in the overall percentage reject rate across all examinations from 9.9% to 8.1% when the hospital changed from using a conventional film based system to a CR system. There was a further reduction in the reject rate to 7.3% when the hospital moved to a hospital-wide PACS system, but this change was not statistically significant. Using estimations of the total number of images used, the percentage reject rates were 6.6% for film, 5.5% for CR and 5.5% for PACS. Thus, if the radiation dose for each image is unchanged, and the same types of images are used for the examination of each body area, a move from conventional film imaging to phosphor plate imaging provides the potential to reduce the patient population dose.