One particular type of digital system uses a Memory Phosphor Plate (a.k.a. PSP -- Photostimulable Phosphor) in place of the film. After X-ray exposure the plate (sheet) is placed in a special scanner where the latent formed image is retrieved point by point and digitized, using laser light scanning. The digitized images are stored and displayed on the computer screen. This method is halfway between old film-based technology and current direct digital imaging technology. It is similar to the film process because it involves the same image support handling but differs because the chemical development process is replaced by the scanning process. This is not much faster than film processing and the resolution and sensitivity performances are contested. However, it has the clear advantage to be able to fit within any pre-existing equipment without modification because it replaces just the existing film.
Also, sometimes the term "Digital X-rays" is used to designate the scanned film documents which are handled by further computer processing.
Other types of digital imaging technologies use electronic sensors. A majority of them first convert the X-rays into visible light (using a GdO2S or CsI layer), which is further captured using a CCD or a CMOS image sensor. Some of them use a hybrid arrangement which first converts the X-rays into electricity (using a CdTe layer) and then captures this electricity as an image with a reading section based on CMOS technology.
