Asbestos-related pleural and parenchymal fibrosis: detection with high-resolution CT

Twenty-nine subjects with occupational asbestos exposure and clinical asbestosis were examined with high-resolution computed tomography (HRCT) to determine its sensitivity, relative to that of conventional computed tomography (CT), for detection of benign asbestos-related disease. Thin-section HRCT scans were obtained at five discrete levels through the mid and lower thorax in both prone and supine positions. The same technique was used in 34 age-similar control patients. Parenchymal abnormalities were seen most frequently in the posterior portion of the lung bases in the asbestos-exposed subjects. HRCT prone scans enabled basal structural abnormalities to be reliably distinguished from gravity-related physiologic phenomena in 25 asbestos-exposed subjects. HRCT was more sensitive than CT in detection of both pleural and parenchymal fibrosis. In subjects with clinical asbestosis, HRCT demonstrated parenchymal abnormality in 96%, compared with 83% for CT. Similarly, pleural thickening was shown in 100% of subjects at HRCT, compared with 93% at CT. HRCT could be an important adjunct in the evaluation of asbestos-related pleuroparenchymal fibrosis. An HRCT study including prone scans is a sensitive, reliable means of detecting thoracic abnormalities in asbestos-exposed individuals.