Asbestos-related pleural disease and asbestosis: a comparison of CT and chest radiography

High-resolution CT (HRCT) has the ability to demonstrate both asbestos-related pleural disease and parenchymal abnormalities consistent with asbestosis. The role of CT in the diagnosis of asbestosis can be defined by comparing it with radiography. We evaluated 60 men who had a history of occupational exposure to asbestos and whose outside chest radiographs were considered abnormal. Chest radiographs (inside films) and HRCT were performed in all patients at our institution and were interpreted independently by experienced radiologists. Outside film results were compiled from the submitted reports. The final conclusion regarding the interpretation of the radiologic examinations was determined by consensus when disagreements existed. Positive predictive values (the likelihood that a positive report is correct) for pleural disease were: outside films 56%, inside films 79%, HRCT 100%. The positive predictive values for parenchymal disease were: outside films 51%, inside films 83%, HRCT 100%. The addition of HRCT to chest radiography is most useful in eliminating false-positive diagnoses of asbestos-related pleural disease caused by subpleural fat and false-positive diagnoses of parenchymal asbestosis in patients with extensive plaques or emphysema obscuring lung detail. The interpretation of chest radiographs in patients exposed to asbestos is often extremely difficult and subjective, and we recommend that positive findings (except calcified plaques) be confirmed with HRCT.