Subpleural micronodules in diffuse infiltrative lung disease

Among the basic CT signs of diffuse pulmonary parenchymal diseases, the presence of subpleural micronodules (SPMNs) has rarely been evaluated. They are defined as small, rounded, hemispheric or triangular opacities in the posterior cortex of the upper lobes. The aims of this paper are to identify their frequency in diffuse infiltrative lung disease (DILD) and to provide pathologic-CT correlations. A total of 459 patients with DILD were evaluated in three groups: group 1 (n = 110), coal miners with coal worker's pneumoconiosis (CWP); group 2 (n = 130), coal miners without CWP; and group 3 (n = 219), patients with nonoccupational DILD