Registration of vascular 3D data sets obtained from multiple-view reconstructions

Three-dimensional (3D) vessel data from CTA or MRA are not always available prior to or during endovascular interventional procedures, whereas multiple 2D projection angiograms often are. Therefore, we are developing methods for combining vessel data from multiple 2D angiographic views obtained during interventional procedures to provide 3D vessel data during these procedures. Multiple projection views of vessel trees are obtained. Vessel regions to be analyzed are selected. One of the 2D images is selected as a common image. Initial pairwise imaging geometry relationships are calculated from the gantry information, and 3D vessel centerlines are calculated using pairwise epipolar constraints. The imaging geometries of each of the other views (relative to that of the common image) are then iteratively refined so as to minimize the differences between all pairwise calculated 3D vessel centerlines, and an average centerline is calculated. Without refinement, the average difference between the centerlines is approximately 9 mm, whereas after refinement, the average difference is approximately 1 mm. In addition, the average centerline is smoother. Our results indicate that this technique will provide more reliable vessel centerlines without increasing dose to the patient.