Final answer:
High-intensity light exposure after scanning with a photomultiplier tube erases the CR imaging plate completely, readying it for reuse.
Step-by-step explanation:
After a photostimulated luminescent phosphor of a CR imaging system has been scanned by the photomultiplier tube reader, the plate is exposed to high-intensity light to erase the image completely. This process is necessary to prepare the plate for the next imaging procedure by removing any residual image data that could compromise new image captures. Photomultiplier tubes play a crucial role in converting the light output from scintillators into electrical signals, based on the photoelectric effect. Each successive stage amplifies the signal, which can then be used to construct sophisticated diagnostic images.