Computed radiography uses an imaging plate (IP) instead of film to record X-ray images. The IP contains photostimulable phosphors that store X-ray energy. Scanning the IP releases the energy, producing electronic signals, which are converted to digital values. Barium fluorohalide (BaFX) phosphors in a high-density layer deliver the sensitivity, sharpness and low noise demanded in computed radiographic diagnosis. An IP is inserted in a cassette for X-ray exposure.