Comparison of computed tomographic lung density with haemodynamic data of the pulmonary circulation

Computed tomographic (CT) lung density measurements were prospectively correlated with pulmonary haemodynamic data in 33 patients with chronic heart disease. Cardiac catheterisation and five specific computed tomographic scans (three at nearly total lung capacity, one at functional residual capacity, and one at residual volume) were performed. There was a significant correlation between anterior lung density and mean pulmonary artery pressure (r = 0.86), pulmonary vascular resistance (r = 0.80), and pulmonary artery wedge pressure (r = 0.65). Lung density, as measured by CT, thus provides a valuable estimate of pulmonary arterial pressure and pulmonary vascular resistance, but is affected by other pathological conditions, such as emphysema and congestional or post-inflammatory fibrosis.