Radiology 2007; 242:258-266.
Copley SJ, Lee YC, Hansell DM, Sivakumaran P, Rubens MB, Newman-Taylor AJ, Rudd EM, Musk AW, Wells AU.
PURPOSE: To retrospectively correlate the extent of individual diseases seen at thin-section computed tomography (CT) with pulmonary function in an initial group of patients with asbestos-related parenchymal disease (asbestosis) and to test these findings in a subsequent group of patients whose CT scans were retrospectively identified.
MATERIALS AND METHODS: This retrospective study had Institutional Review Board approval; informed consent was not required. The study included 133 individuals who had been exposed to asbestos. In the initial study group (81 patients; 79 men, two women; median age, 67 years), two observers used a CT scoring system to quantify the extent of pulmonary fibrosis, diffuse pleural thickening, small-airways disease, and emphysema. Multivariate equations were formulated by using independent CT variables to predict changes in total lung capacity (TLC) and carbon monoxide diffusing capacity (Dlco). The validity of these equations was then tested in a subsequent group of patients (52 patients; all men; median age, 60 years).
RESULTS: At thin-section CT, the extent of asbestos-induced pleuro-pulmonary disease and emphysema correlated significantly with physiologic impairment (P < .001). Combined CT variables predicted 58% and 57% of the variability in TLC and Dl.CO, respectively, despite considerable variation in the proportion of coexisting pathologic conditions. When predictive equations with CT variables derived from the initial study group were applied to the subsequent study group, predicted TLC (p = 0.75, P < .001) and Dlco (p = 0.64, P < .001) correlated strongly with measured values.
CONCLUSION: The proposed CT system provides a semiquantitative method for assessing the relative contribution of asbestos-induced pleuropulmonary disease and smoking-related emphysema to functional impairment.