Imaging of occupational lung diseases

High resolution chest CT (HRCT) has led to significant advances in our understanding of occupational lung diseases. It allows earlier diagnosis of mild or subtle lung disease, though a normal HRCT examination does not exclude disease. The specificity of HRCT is greater than that of the chest radiograph. In silicosis and coal-workers' pneumoconiosis, HRCT allows detection of functionally significant emphysema or conglomerate masses. In asbestos-exposed workers, CT allows early detection of pleural plaques and asbestosis. The radiologic findings in berylliosis are similar to those of sarcoidosis, The CT pattern of hypersensitivity pneumonitis is often highly suggestive of this diagnosis, but chronic hypersensitivity pneumonitis may mimic idiopathic pulmonary fibrosis. The ILO classification system is widely used to identify and quantify radiographic signs of pneumoconiosis, but is limited by the lack of sensitivity and specificity of the chest radiograph. In the future, accurate quantification of lung disease may be possible using chest CT.