What does PSP stand for in computed radiography?

• A. Phase-stimulable Phosphor
• B. Photo-stimulable Phosphor
• C. Phosphor Screen Plate
• D. Phosphor storage plate

Answer: (B)

PSP stands for Photo-stimulable Phosphor. In computed radiography, the imaging plate is coated with a phosphor material that stores energy when exposed to x-rays. Those stored energy states are trapped electrons. When the plate is later scanned with a laser, the trapped electrons are released and emit light (photostimulated luminescence). The emitted light is captured and converted into a digital image. The key idea is that the plate uses a phosphor that is capable of storing energy and then being stimulated to emit light, hence the term photostimulable phosphor. Alternatives like “storage plate” or “screen plate” refer to different wording or concepts, but the established term for the material itself is Photo-stimulable Phosphor.