DIFFERENTIATION OF THE ILO BOUNDARY CHEST ROENTGENOGRAPH (0 1 TO 1/0)IN ASBESTOSIS BY HIGH-RESOLUTION COMPUTED-TOMOGRAPHY SCAN, ALVEOLITIS, AND RESPIRATORY IMPAIRMENT/

High-resolution computed tomography (HRCT) scans have been advocated a s providing greater sensitivity in detecting parenchymal opacities in asbestos-exposed individuals, especially in the presence of pleural fi brosis, and having excellent inter- and intraobserver reader interpret ation. We compared the 1980 International Labor Organization (ILO) Int ernational Classification of the Radiographs of the Pneumoconioses for asbestosis with the high-resolution CT scan using a grid scoring syst em to better differentiate normal versus abnormal in the ILO boundary 0/1 to 1/0 chest roentgenograph. We studied 37 asbestos-exposed indivi duals using the ILO classification, HRCT grid scores, respiratory symp tom questionnaires, pulmonary function tests, and bronchoalveolar lava ge. We used Pea-son correlation coefficients to evaluate the linear re lationship between outcome variables and each roentgenographic method. The normal HRCT scan proved to be an excellent predictor of ''normali ty,'' with pulmonary function values close to 100% for forced vital ca pacity (FVC), forced expiratory volume in 1 second (FEV(1)), total lun g capacity (TLC), and carbon monoxide diffusing capacity (DLCO) and no increase in BAL inflammatory cells. Concordant HRCT/ILO abnormalities were associated with reduced FEV(1)/FVC ratio, reduced diffusing capa city, our study, the ILO classification and HRCT grid scores were both excellent modalities for the assessment of asbestosis and its associa tion with impaired physiology and alveolitis, with their combined use providing statistical associations with alveolitis and reduced diffusi ng capacity.