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 left or right coronary tree from digitized biplane coronary cineangiograms. 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 controlled by a VAX-11/750 computer. First, the parameters of the two projections 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 after the coronary injection, with unchanged geometric configuration. The coronary arteries of interest are then 3D-reconstructed from a pair of cineframes showing them fully opacified. This allows the intravascular volumes needed for flow determination to be computed. Preliminary measurements in 12 patients showed that flow values obtained angiographically in the left descending coronary artery correlate well with the values measured simultaneously by thermodilution in the great cardiac vein (Qangio = 0.83 x Qthermo + 16.1 ml, r = 0.87, n = 29).