Abstract
Digital image processing techniques are applied to the extraction of three-dimensional (3-D) information on coronary arteries from mutually orthogonal cineangiograms (e. g. RAO 30 degrees and LAO 60 degrees). Both cineangiograms are of the same scale factor and carefully registered in space. The registration in time is done by determining the end-diastole phase and the end-systole phase on the cineangiograms. The registration of left and right coronary arteries (LCA and RCA) is done by detecting a small intentional leak of contrast material so as to show both entrances of LCA and RCA.
Corresponding points in RAO and LAO images are conversationally selected on a display and their 3-D coordinates are calculated. 3-D structure of coronary arteries are approximated by lines which connect points thus obtained. Its view from any direction can be displayed. Branches are color coded to make the identification easy. A 16mm film and a video tape are used to show the rotation of 3-D structure around an arbitrary axis. Stereoscopic pairs of arteries are also presented. These display techniques are quite effective in understanding the 3-D structure of coronary arteries.
The 3-D spatial shape surrounded by coronary arteries is obtained as the stacking of cross sections. This shape can be considered to reflect the outer shape of the heart. Each cross section is approximated by the third order spline curve which connects the cross points between arteries and the cross plane.
