Automated morphologic evaluation of pulmonary arteries in primary pulmonary hypertension.

Pulmonary wedge angiograms have been shown to reflect the severity of pulmonary vascular disease in congenital heart disease. Thirteen pulmonary wedge angiograms with a balloon occlusion catheter were performed in 11 adult patients (five normals and six with primary pulmonary hypertension [PPH]) and their features related to the resting pulmonary artery pressure (PAP). Individual cine frames from each study were selected and digitized with a computer-assisted operator-interactive program. By fitting densitometric profiles from the vessel segments, serial arterial cross-sectional diameters were calculated from mathematically derived points. There was a strong correlation between arterial taper (T, change in vessel caliber per unit axial length) and a power function of mean PAP with T = 0.304 X PAP-0.59, R = .91, P less than .001. These results demonstrate a correlation between an angiographically derived morphologic characteristic of the pulmonary vasculature (taper) and a hemodynamic parameter (PAP) in PPH. This offers a method to follow the course of the disease and the effects of drug therapy by assessing anatomic changes in the vessels.