Accurate 3-D reconstruction of tortuous coronary vessels using biplane angiography and intravascular ultrasound

At present, 3-D reconstructions of coronary vessels are generated from intravascular ultrasound (IVUS) pullback sequences by stacking up EGG-gated segmented IVUS frames. Since this approach results in straight vessel reconstructions, it deafly fails in tortuous coronary arteries. This shortcoming may be overcome by data fusion with biplane angiography. The 3-D course of the vessel is first derived from angiograms and then combined with segmented IVUS images in order to obtain a spatially correct and anatomically complete vessel reconstruction. In this paper, different approaches to two problems associated with the data fusion method are discussed: the definition of the pullback path and the estimation of IVUS catheter twist during pullback. A procedure for image acquisition, segmentation, mapping, and interpolation is proposed that has been designed with respect to its clinical applicability. In-vitro validations of our previously reported algorithm for analytic catheter twist quantification is presented along with data fusion results of coronary arteries in cadaveric pig hearts.