3D DETERMINATION OF THE INTRAVASCULAR VOLUME AND FLOW OF CORONARY-ARTERIES

An angiographic method for measurement of absolute coronary blood flow in patients was developed. It is based on 3D-reconstruction of the le ft or right coronary tree from digitized biplane coronary cineangiogra ms. The apparatus is presently composed of a 35-mm cinefilm projector with video camera and a 512 x 512 x 8-bits image array processor contr olled by a VAX-11/750 computer. First, the parameters of the two proje ctions are determined in the form of two 4 X 3 matrices from a pair of cineframes showing a 4-cm cube bearing markers. The cube is filmed af ter the coronary injection, with unchanged geometric configuration. Th e coronary arteries of interest are then 3D-reconstructed from a pair of cineframes showing them fully opacified. This allows the intravascu lar volumes needed for flow determination to be computed. Preliminary measurements in 12 patients showed that flow values obtained angiograp hically in the left descending coronary artery correlate well with the values measured simultaneously by thermodilution in the great cardiac vein (Q(angio) = 0.83 x Q(thermo) + 16.1 ml, r = 0.87, n = 29).