CR uses an imaging plate coated with storage phosphors to capture x-rays as they pass through the patient. Trace amounts of impurities are added to the phosphor materials in a process called "doping," to alter their crystalline form and physical properties. When irradiated, the enhanced phosphors absorb and store x-ray energy in gaps in their altered crystal structure. This trapped energy comprises a latent image; when stimulated by additional light energy of the proper wavelength, the trapped energy is released.

In modern CR systems, storage phosphors commonly are stimulated with a low-energy laser to release visible light wherever x-rays have been absorbed. This light is captured and converted into an electrical signal, which is converted to data that can be transmitted to remote systems or locations, displayed on laser-printed films or softcopy workstations and stored digitally.

Other than the absence of film and chemical processing, computed radiography - including equipment for capture - works very much like conventional film-screen radiology. The difference is in the benefits.

Phosphor plates, like film, are stored in cassette format. In fact, existing analog equipment, from generators to x-ray tubes, can be used with a CR system. Technicians simply insert a CR cassette instead of a film cassette, take the x-ray, and then transfer the exposed cassette with x-ray images into the CR unit that scans and translates the contents into data, to be sent to soft copy display, archives, or hard copy print-out.

Compared to conventional film-screen capture, CR technology speeds image availability and can reduce image retakes and duplication costs, to boost workflow and productivity. CR also offers more options for displaying, sharing and storing images.

From the core precepts of storage phosphor-based image generation, improvements in phosphor screen coating, optics and scanning systems, and image data processing have increased the sophistication of computed radiography.