UNDER-STANDING CORONARY-ARTERY MOVEMENT - A KNOWLEDGE-BASED APPROACH

The aim of this paper is to describe a knowledge-based system that int erprets three-dimensional (3D) coronary artery movement, using data fr om digital subtraction angiography image sequences. Dynamic informatio n obtained from artery centerline 3D reconstruction and optical flow e stimation, is classified according to experimental evidence indicating that artery displacements are quasi-homogeneous by a segment analysis . Characteristic motion features like displacement direction, perpendi cular/radial components, rotation direction, curvature and torsion are qualitatively described from an image sequence using symbolic labels. These facts are then related and interpreted using anatomical-functio nal knowledge provided by a specialist, as well as spatial and tempora l knowledge, applying spatio-temporal reasoning schemes. Facts, knowle dge and reasoning rules are stated in a declarative form. Detailed exa mples of local and global interpretation results, using a real reconst ructed angiographic biplane image sequence are presented in order to i llustrate how our system suitably interprets coronary artery dynamic b ehavior. (C) 1998 Elsevier Science B.V. All rights reserved.