Diffusing Capacity for Carbon Monoxide Correlates Best With Tissue Volume From Quantitative CT Scanning Analysis

Quantitative analysis of high-resolution chest CT scan (QCT) is an established method for determining the severity and distribution of lung parenchymal destruction in patients with emphysema. Diffusing capacity of the lung for carbon monoxide (Dlco) is a traditional physiologic measure of emphysema severity and is probably influenced more by destruction of the alveolar capillary bed than by membrane diffusion per se. We reasoned that Dlcoshould correlate with tissue volume from QCT.