RESTRICTIVE LUNG-FUNCTION AND ASBESTOS-INDUCED PLEURAL FIBROSIS - A QUANTITATIVE APPROACH

To assess further the clinical significance of asbestos-induced pleura l fibrosis, we used a computer algorithm to reconstruct images three d imensionally from the high-resolution computerized tomography (HRCT) s can of the chest in 60 asbestos-exposed subjects. Pulmonary function t ests, chest radiographs, and HRCT scans were performed on all study su bjects. The volume of asbestos-induced pleural fibrosis was computed f rom the three-dimensional reconstruction of the HRCT scan. Among those with pleural fibrosis identified on the HRCT scan (n = 29), the volum e 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 a sbestos-induced pleural fibrosis and restrictive lung function, we com pared the computer-derived estimate of pleural fibrosis to the total l ung capacity and found that these measures were inversely related (r = -0.40; P = 0.002). After controlling for age, height, pack-years of c igarette smoking, and the presence of interstitial fibrosis on the che st radiograph, the volume of pleural fibrosis identified on the three- dimensional reconstructed image from the HRCT scan was inversely assoc iated with the total lung capacity (P = 0.03) and independently accoun ted for 9.5% of the variance of this measure of lung volume. These fin dings further extend the scientific data supporting an independent ass ociation between pleural fibrosis and restrictive lung function.