HYPERSENSITIVITY PNEUMONITIS - CT FINDING S

Chest radiographs and computed tomographic scans obtained from ninetee n patients with hypersensitivity pneumonitis were reviewed retrospecti vely. Thirteen of them had a subacute form. Six of them had a chronic form. In subacutes forms, CT scans were normal in two patients. In the 11 other cases, CT findings were ground glass attenuation (n = 10), n odules (n = 7) and linear opacities (n = 5), Ground glass attenuation was diffuse or patchy, Two patterns are quite suggestive of hypersensi tivity pneumonitis: the association of micronodules and ground glass a ttenuation and the presence of hyperlucent secondary lobules within th e ground glass. After cessation of exposure, CT showed a return to nor mal or improvement. Ground glass opacities, nodules and also linear op acities disappeared. CT scans were always abnormal in chronics forms, CT findings were linear opacities (n = 6), ground glass attenuation (n = 4), micronodules (n = 2) and cysts (n = 3).