Managing Digital Radiography: New Technologies, New Concepts

The introduction of digital technology to radiography has brought new concepts to the attention of radiology professionals. Certain basic truths about film-based radiographic imaging don't apply to digital technologies. For example, image quality on conventional screen-film systems is governed by the characteristics of the film and the screen. Since all screen-film systems rely on the same technology, systems with similar specifications will produce images of similar quality. On the other hand, the new digital x-ray systems[1] use a range of different technologies, which makes it harder to compare their image-producing capabilities. And suppliers of digital systems are claiming superiority over competing products by churning out new quantitative measures of image quality. To objectively compare systems, buyers need to know which of these measures are significant and how to interpret them.

This article introduces and explains some of the concepts that radiology professionals may be unfamiliar with, in addition to some old concepts—such as contrast resolution, spatial resolution, and noise—that may need to be reviewed. Understanding these will help healthcare facilities get a better grasp on and realize the greatest benefits from digital radiography.

An x-ray detector that cannot produce images of sufficient quality to permit accurate interpretation is useless. Given that different digital systems produce different levels of image quality, potential buyers...