Using computed radiography — how does it compare to film-screen radiography?

Many veterinary practices have recently switched from using film-screen (plain film) radiography to computed radiography (CR). Practice managers have been relatively quick to recognise the benefits associated with using CR, many of which are financial considerations. Outwardly these two modalities appear similar, with both employing a removable cassette which has to be inserted into a processing machine. However, working with CR is not as simple as it seems. Due to the number of inherent differences between the two modalities, there are many new factors to understand in order to get the most out of a CR system and to work safely. While there is no substitute for proper training on any new piece of equipment, the purpose of this article is to explain the most important differences between film-screen radiography and CR, enabling the veterinary nurse to apply a greater degree of knowledge when using CR.

If plain film packets are incorrectly filed it may take a long time to locate them. Films may also get lost, especially if sent in the post or if filed incorrectly. In these cases there is sometimes no alternative but to rely on the written report — if there is one — or to re-radiograph the patient. Virtually all of the problems associated with archiving plain film radiographs are overcome when using CR. The amount of space required is vastly reduced, and it takes only a few seconds to retrieve digital images from a digital archive or PACS system. Another benefit of CR is that it allows people to access the images from different locations at the same time. It is also virtually impossible to lose a CR image, and although computer systems have been known to fail on the odd occasion, regularly backing up the system up by disc can negate this concern. Being able to send or access images via the internet has the obvious advantage of convenience and time, and has led to the practice of teleradiology whereby images are reported remotely by a radiologist. This is a huge benefit for remote practices and those clinicians working out of hours.