AIMS: To document the presence and extent of air trapping on high resolutio
n computed tomography (HRCT) in patients with pulmonary sarcoidosis and cor
relate HRCT features with pulmonary function tests.
METHODS: Twenty-one patients with pulmonary sarcoidosis underwent HRCT and
pulmonary function assessment at presentation. Inspiratory and expiratory H
RCT were assessed for the presence and extent of air trapping, ground-glass
opacification, nodularity, septal thickening, bronchiectasis and parenchym
al distortion. HRCT features were correlated with pulmonary function tests.
RESULTS: Air trapping on expiratory HRCT was present in 20/21 (95%) patient
s. The extent of air trapping correlated with percentage predicted residual
volume (RV)/total lung capacity (TLC) (r = 0.499; P < 0.05) and percentage
predicted maximal mid-expiratory flow rate between 25 and 75% of the vital
capacity (r = -0.54; P < 0.05), Ground-glass opacification was present in
four of 21 (19%), nodularity in 18/21 (86%), septal thickening in 18/21 (86
%), traction bronchiectasis in 14/21 (67%) and distortion in 12/21 (57%) of
patients; there were no significant relationships between these CT feature
s and pulmonary function results.
CONCLUSION: Air trapping is a common feature in sarcoidosis and correlates
with evidence of small airways disease on pulmonary function testing. (C) 2
000 The Royal College of Radiologists.