Radiologic and pathologic characteristics of mixed dust pneumoconiosis

Modern radiologic technology has to led to increased diagnostic efficacy and accuracy in demonstrating pulmonary changes secondary to occupational dust exposure. This article presents three cases of typical and two cases of atypical silicosis with rounded atelectasis as seen in computed radiographic (CR), computed tomographic (CT), and scintigraphic images and autopsied lung specimens. Chest radiographs revealed both small rounded and small irregular opacities. Small irregular opacities on chest radiographs often proved to be reticular or honeycomb patterns on CT scans. Irregular opacities seen on CR and CT images represented interstitial fibrotic or mixed dust fibrotic changes associated with the accumulation of birefringent particles and emphysematous change, as noted at histologic analysis. CT scans and scintigrams were useful for visualizing parenchymal abnormalities, especially fibrotic change, emphysematous change, and pleural abnormalities.