Imaging plate

The CR imaging plate contains photostimulable storage phosphors, which store the radiation level received at each point in local electron energies. When the plate is put through the scanner, the scanning laser beam causes the electrons to relax to lower energy levels, emitting light that is detected by a photo-multiplier tube, which is then converted to an electronic signal. The electronic signal is then converted to discrete (digital) values and placed into the image processor pixel map. Imaging plates can theoretically be re-used thousands of times if they are handled carefully, although handling under industrial conditions may result in damage after a few hundred uses. An image can be erased by simply exposing the plate to a room-level fluorescent light. Most laser scanners automatically erase the image plate after laser scanning is complete. The imaging plate can then be re-used. In the software, the scanned image is encrypted so that the original data is kept secure and can not be tampered with. Reusable phosphor plates are environmentally safe.