The X-ray image intensifier is mainly composed of image intensifier tube, tube container, special high voltage power supply built in tube container and low voltage power supply for driving high voltage power supply.
Image contrast mainly refers to the placement of a circular lead plate equal to 10% of the effective area of the input screen in the center of the enhancement tube input screen. From the input screen, the maximum brightness of the part without lead shadow and the brightness of the part with lead plate are observed. The ratio of the two is called image contrast.
Because the output screen of X-ray image intensifier tube has background gray level, its image contrast will be lower than that of ordinary fluorescent screen.