II.X線写真の画質 : 螢光増感紙と写真フィルム系(第31回総会)

抄録

Granularity of a screen-film radiographic system was assessed physically and visually by examinig various combination of films and screens. We pointed out that the dominant factor which affects granularity of the system was quantum mottle, and the contribution of this factor to total radiographic granularity can be estimated as about 60%. Then, we tried to get a new high-speed radiographic system of high image quality. The system was designed by making use of green-emitting intensifying screens which contain rare earth phosphors, and combining these screens with a green-sensitive orthochromatic medical X-ray film. The new system provides maximum light emission which can be absorbed efficiently into emulsion layers and enables reduction of X-ray exposure to 1/5 or even to 1/10 in comparison with normal system. The new system gives entirely equal diagnostic information or it gives superior image quality compared with the conventional system.