Abstract
The diagnostic performance of high-resolution computed tomography (HRCT) and conventional chest radiography (CXR) has not been compared on a large sample of subjects with widely-different degrees of cumulative exposure to asbestos, i.e., with ample differences in pre-test likelihood of disease. We evaluated 1427 ex-workers in chrysotile millers and mines who were separated into 4 groups (Gr) of decreasing cumulative exposure (Groups I to IV). The prevalence of either parenchymal or pleural abnormalities were markedly reduced as exposure decreased (p<0.01). Assuming HRCT as the criterion method, CXR was associated with increased false-positive and false-negative rates for parenchymal and pleural abnormalities, respectively. These findings were consistent across the groups of asbestos exposure (table).
We conclude that decreased exposure to asbestos led to a marked reduction in the prevalence of chest abnormalities according to either CXR or HRCT. CX, however, was associated with unacceptable rates of false-positive for asbestose and false-negative for pleural plaques, independent of cumulative exposure.
Supported by: CNPq/Ministry of Science and Technology, FUNAPE (GO) and Brazilian Crysotile Institute.
- © 2011 ERS