Distribution of ventilation-perfusion ratios in pulmonary sarcoidosis.

In 14 patients with advanced stage pulmonary sarcoidosis the distribution of regional ventilation-perfusion ratios (V/Q) was obtained by quantitative analysis of ventilation-perfusion single photon emission computed tomography (SPECT) of the lungs. In 6 patients normal V/Q distributions were found with a decreased DLCO in only one of them. In 8 patients abnormal distributions of V/Q ratios were found. Six of these patients also had a decrease in diffusing capacity for CO (DLCO). It is suggested that the decrease in DLCO in these patients is partly a result of uneven distribution of V/Q ratios.