Digital cine angiographic evaluation of pulmonary blood flow velocity in ventricular septal defect.

Forty-one routine right ventricular cineangiograms of children with ventricular septal defect (VSD) were evaluated with a digital image processing system. The purpose was to extract from the cineangiogram functional images that would provide information about pulmonary blood flow in these patients. The time delay of the contrast bolus between the main pulmonary artery and peripheral lung fields was measured and called "arrival time." By measuring the arrival time in three different points of each lung (apex, horizontal, basis), it was possible to express the mean arrival time for both lungs in a single figure. A group of patients without heart disease showed an arrival time of 1.3 +/- 0.3 seconds. In VSD with increased pulmonary blood flow from the left to right shunt, the arrival time decreased to 0.76 +/- 0.2 seconds. An increase in pulmonary vascular resistance with reduced L-R shunt led to an increased arrival time of 1.4 +/- 0.4 seconds.