131I macro-aggregated albumin perfusion scanning and chest radiography in asbestos exposure.

131I macro-aggregated albumin perfusion scanning and conventional radiography were used to study the lungs of 108 men who had been exposed to asbestos dust. The presence or absence of basal crackles was recorded in all cases. Forced vital capacity (FVC) was measured in 94 cases. Underperfusion of the lower zones of the lungs was considered to be present in only 8 of 39 cases with small irregular opacities classified as category 1/0 or higher on the 1971 International Labour Organization classification for pneumoconiosis. In 5 of 69 cases classified in categories less than 1/0, perfusion in the lower zones appeared to be impaired. Details of these cases are given. Underperfusion was more common among men with basal crackles or reduced FVC (less than 80% of predicted value) but this trend was not statistically significant.