Pulmonary clearance of 99mTC-DTPA aerosol in patients with silicosis]

99mTc-DTPA clearance was studied in 11 healthy nonsmokers, 20 patients with simple or complicated silicosis (5 of simple, 15 of complicated). The results indicated that both the patients with simple silicosis (T1/2 32.8 +/- 14.4min) and complicated silicosis (T1/2 26.6 +/- 8.5min) showed faster clearance of inhaled 99mTc-DTPA than observed in healthy nonsmokers (77.9 +/- 11.7min, p < 0.01). Regional clearance apico-basal difference was found in patients with silicosis. This study presents evidence of increased pulmonary epithelial permeability and regional distribution of pulmonary epithelial permeability in silicosis.