Anatomical lung shunting in pulmonary fibrosis

Eleven patients with cryptogenic fibrosing alveolitis were evaluated for the presence of pulmonary shunting by injection of radiolabelled particles of macroaggregated albumin larger than 10 micron in diameter and by body scanning with a gamma camera. The mean shunt of 9% (SD 2%) in the patients was not significantly different from the mean shunt of 7% (2%) measured in 10 normal controls. These findings suggest that shunting is not an important part of the gas exchange abnormalities noted in such patients.