High-resolution CT in silicosis: correlation with radiographic findings and functional impairment.

Objective: To assess high-resolution computed tomography (HRCT) findings in silicosis and to better define the role of HRCT in early detection of parenchymal abnormalities in silica-exposed workers.
Methods: Forty-one stone carvers were evaluated with chest radiographs (CR), HRCT, and pulmonary function tests (PFT). Inter-reader agreement was calculated using the kappa statistic (k). Correlation between radiographic and HRCT profusion scores and PFT was assessed using the Spearman correlation coefficient.
Results: The most common HRCT findings were branching centrilobular structures, seen in 28/41 workers (68.3%). Nodules consistent with silicosis were detected in 53.7% workers on CR and in 56.1% workers on HRCT. Inter-reader agreement for diagnosis of silicosis was better on HRCT (k = 0.84) than on CR (k = 0.54). Small opacity profusion on HRCT correlated inversely with total lung capacity and FVC%.
Conclusion: Profusion of opacities on HRCT correlates with functional impairment. The presence of branching centrilobular structures may be helpful in early recognition of silicosis.