OBJECTIVETo compare the image quality of T grain green sensitive film (TML-1) and Lanex Gd(2)O(2)S rare earth intensifying screen with that of XK-1 blue sensitive film and calcium tungstate (CaWO(4)) intensifying screen, and to study the application of T grain technic to the diagnosis of lung diseases.

METHODS160 coal miners were randomly selected to take both TML-1 and XK-1 chest film of high kV radiographs at the same time. Silver halide granule, fluorescence of intensifying screen, radiographic parameters, the density at different points in the lung and chest radiographs were observed.

RESULTSSilver grains in TML-1 film were more homogeneous in distribution than in XK-1 film. Luminous intensity of Lanex Gd(2)O(2)S rare earth intensifying screen was brighter than CaWO(4) intensifying screen in the same exposure. The exposure doses of TML-1 film was reduced to one third of XK-1 film. The density of chest radiographs was 0.24 to 2.74 in TML-1 film, and 0.30 to 2.60 in XK-1 film. There were greater exposure latitude and more informations in TML-1 film. By apertured-disc observation, the fine structure of lung in TML-1 film was clearer than in XK-1 film, the shape was more concrete and reliable, visualizability was stronger.

CONCLUSIONT grain technique may obviously improve the clearness and resolution of image, and enhance the transmission of information, as well as increase the diagnostic informations.