Restrictive lung function and asbestos-induced pleural fibrosis. A quantitative approach.

To assess further the clinical significance of asbestos-induced pleural fibrosis, we used a computer algorithm to reconstruct images three dimensionally from the high-resolution computerized tomography (HRCT) scan of the chest in 60 asbestos-exposed subjects. Pulmonary function tests, chest radiographs, and HRCT scans were performed on all study subjects. The volume of asbestos-induced pleural fibrosis was computed from the three-dimensional reconstruction of the HRCT scan. Among those with pleural fibrosis identified on the HRCT scan (n = 29), the volume of the pleural lesion varied from 0.01% (0.5 ml) and 7.11% (260.4 ml) of the total chest cavity. To investigate the relationship between asbestos-induced pleural fibrosis and restrictive lung function, we compared the computer-derived estimate of pleural fibrosis to the total lung capacity and found that these measures were inversely related (r = -0.40; P = 0.002). After controlling for age, height, pack-years of cigarette smoking, and the presence of interstitial fibrosis on the chest radiograph, the volume of pleural fibrosis identified on the three-dimensional reconstructed image from the HRCT scan was inversely associated with the total lung capacity (P = 0.03) and independently accounted for 9.5% of the variance of this measure of lung volume. These findings further extend the scientific data supporting an independent association between pleural fibrosis and restrictive lung function.