CT for asbestosis: value and limitations.

CT is more sensitive than clinical evaluation for the detection of asbestosis but is inevitably less sensitive and less specific than pathologic evaluation. For the asbestos-exposed individual, CT is useful for the evaluation of suspected lung masses, particularly rounded atelectasis [15], for identifying pleural plaques, and for confirming unequivocal asbestosis (grade 2 or grade 3 [8]). CT also will identify and quantify emphysema as a cause of physiologic impairment. Because clinicians commonly use CT to resolve clinical uncertainties, radiologists often feel pressured to categorize disease as unequivocally present or absent. Gamsu et al. [8] show that the borderline between normal and abnormal is not always sharply defined. In the absence of pathologic proof, the diagnosis of asbestosis must be based on a thoughtful evaluation of the likelihood of asbestosis by use of all available clinical, physiologic, and radiologic information. The scoring systems used by Gamsu et al. [8] offer a practical approach to defining the likelihood of asbestosis based on CT appearances.