The effect of image distortion on 3-D reconstruction of coronary bypass grafts from angiographic views

Three-dimensional (3-D) reconstructions of coronary bypass grafts performed from X-ray angiographic images may become increasingly important for the i nvestigation of damaging mechanical stresses imposed to these vessels by th e cyclic movement of the heart. Contrary to what we had experienced with co ronary arteries, appreciable reconstruction artifacts frequently occur with grafts. In order to verify the hypothesis that those are caused by distort ions present in the angiographic images (acquired with image intensifiers), we have implemented a grid correction technique in our 3-D reconstruction method and studied its efficiency with phantom experiments. In this article , the nature of the encountered artifacts and the may in which the dewarpin g correction eliminates them are illustrated by a phantom experiment and by the reconstruction of a real coronary bypass vein graft.