Speed compensated intensifying screen for radiography

Abstract

Disclosed is speed compensated intensifying screen which has a layer of phosphor and a protective layer superposed sequentially on a substrate and further has a light-absorbing layer capable of absorbing part of the light emitted from the layer of phosphor superposed thereon. By this light-absorbing layer, a plurality of regions differing in speed are formed within the layer of phosphor. In the plurality of regions, the speed is continuously changed across the borderlines between the regions. This continuous change in density across the borderlines prevents the borderlines between the regions of speed from appearing as line patterns in the produced X-ray radiograph. The intensifying screen of the grade adapted for X-ray radiography of the chest effects proper speed correction by incorporating therein a plurality of regions of speed formed so as to conform to the various internal organs in the chest such as the upper and lower mediastinums, the hilums of the lung, and the lungfields. The intensifying screen of the grade adapted for X-ray radiography of the head effects proper speed correction by incorporating therein a plurality of regions of speed formed so as to conform to the various parts of the head from the central part through the portion near the scalp. The intensifying screen of the grade adapted for X-ray radiography of the upper and lower jaws and the peripheries thereof effects proper speed correction such as to prevent the shadow of the backbone from giving rise to portion deficient in radiographic density.