What is the purpose of the laser within the CR digitizer?

• A. release the latent image from the PSP layer
• B. release the latent image from the conductor layer
• C. erase the latent image from the PSP layer
• D. erase the latent image from the conductor layer

Answer: (A)

The laser in a CR digitizer is used to read the stored image information by stimulating the phosphor layer. After x-ray exposure, the phosphor storage layer traps some electrons, creating a latent image within that layer. The laser scans the plate and causes those trapped electrons to release their stored energy as light (stimulated luminescence). This emitted light is detected and converted into a digital signal that forms the image. The latent image is in the PSP layer, not the conductor layer, and the laser’s role is reading it, not erasing it. Erasure happens afterward with bright light to reset the plate for the next use.