Computer tomography in the evaluation of pulmonary asbestosis. Preliminary experiences with the EMI general purpose scanner.

Thirteen individuals with varying lengths of exposure to asbestosis were examined by computer tomography with the EMI Scanner. Various pleuroparenchymal abnormalities were found, many not being seen on standard chest films. In some cases, with normal chest radiography, definite pleural involvement could be demonstrated, particularly that in the posterior sulci on the diaphragm and at the mediastinum. Tissue attenuation measurements in regions of parenchymal involvement reached 90 EMI units above normal lung tissue. The normal gravity effect is abolished in cases of parenchymal disease caused by asbestosis. Parenchymal disease was much more obvious on the CT scans than on conventional chest films.