Large-screen image intensifier photofluorography compared with full-size screen-film technique in chest radiography.

Large-screen image intensifier photofluorography revealed a radiation dose and exposure time of about one third of those of a medium speed rare-earth screen/film (Trimax T4/XD) combination for full-size chest radiography. The resolving power of the former technique is somewhat poorer and there is a moderate electron-òptical distortion in the peripheral field. In clinical chest radiography photospot films showed excellent demonstration of the central areas of the image but slight deterioration in peripheral parts. The minification effect of the photofluorographic films is advantageous for visual perception of many anatomic details on chest radiographs. The type of viewing device for photospot films is important.