An imaging plate is coated with what material?

An imaging plate is coated with what material?

• A. Photostimulable phosphor
• B. Silver halide crystals
• C. Cesium iodide
• D. Calcium tungstate

Answer: (A)

The material coating an imaging plate is a photostimulable phosphor. This layer stores the x-ray energy by trapping electrons in the phosphor crystal lattice. Later, a laser scans the plate and stimulates the trapped electrons to release that energy as light, which is then detected to form the image. This storage phosphor is typically europium-doped barium fluorohalides used in CR systems. Why the other materials aren’t used for the coating: silver halide crystals are found in traditional radiographic film, not in the CR imaging plate’s storage layer. Cesium iodide is a scintillator commonly used in some digital detectors to convert x-rays to light, but not the storage phosphor layer of an imaging plate. Calcium tungstate was used in early film-screen phosphors, but again, not as the CR plate coating.

The material coating an imaging plate is a photostimulable phosphor. This layer stores the x-ray energy by trapping electrons in the phosphor crystal lattice. Later, a laser scans the plate and stimulates the trapped electrons to release that energy as light, which is then detected to form the image. This storage phosphor is typically europium-doped barium fluorohalides used in CR systems.

Why the other materials aren’t used for the coating: silver halide crystals are found in traditional radiographic film, not in the CR imaging plate’s storage layer. Cesium iodide is a scintillator commonly used in some digital detectors to convert x-rays to light, but not the storage phosphor layer of an imaging plate. Calcium tungstate was used in early film-screen phosphors, but again, not as the CR plate coating.