Computed Radiography uses which of the following to capture the image?

• A. Photostimulable phosphor plate
• B. Direct digital detector
• C. Film-screen radiography
• D. Image intensifier

Answer: (A)

Computed radiography captures the image using a photostimulable phosphor plate. When X-rays expose the plate, the phosphor stores energy in a latent state. In the CR reader, a red laser scans the plate and releases the stored energy as light (photostimulated luminescence) proportional to the original X-ray exposure. This emitted light is detected and digitized to form the image, and the plate can then be erased and reused. This approach distinguishes CR from direct digital radiography, which uses a solid-state digital detector to convert X-rays directly to a digital signal, and from film-screen radiography, which uses photographic film. It also isn’t the image intensifier used in fluoroscopy, which is for real-time X-ray visualization.