[Contribution of xerography in the discovery of radiolucent billiary calculi (author's transl)].

Used in 100 patients, in whom the gall bladder was badly opacified, and apparently contained no stones, xeroradiography led to the appearance of images of radiolucent calculi on 8 occasions. Furthermore, it enabled a differential diagnosis between lacunae due to lithiasis and gaseous pseudo-lacunae. The weak system transfer density however prevented it being considered other than as a complementary method. Undoubtedly, however it announces the wider possibilities for electronic radiography, of which the images are comparable with a greatly reduced irradiation.