Modern film-screen imaging technology

Despite the major interest in and substantial growth rate of new electronic imaging modalities, conventional film-screen systems continue to be the primary imaging medium in radiography. Screen-film radiography today is directed almost entirely toward rare earth systems which offer greatly improved speed-to-image quality balance over earlier systems. The term rare earth system generally is taken to mean a combination of new improved screen, usually made of a rare earth phosphor, plus a film designed to take maximum advantage of these screens. The physical performance of screen-film systems is described in terms of system speed, contrast, latitude, sharpness or resolution, and image noise. These are complex functions of a number of film and screen properties