Advanced 2D-3D Registration for Endovascular Aortic Interventions: Addressing Dissimilarity in Images Stefanie Demirci a , Oliver Kutter a,b , Frode Manstad-Hulaas c,d (MD), Robert Bauernschmitt b (MD) and Nassir Navab a a Chair for Computer Aided Medical Procedures (CAMP), Technische Universit¨at M¨ unchen, Boltzmannstr. 3, 85748 Garching, Germany; b Cardiovascular Surgery Department, TUM - Deutsches Herzzentrum M¨ unchen, Lazarettstr. 36 , 80636 M¨ unchen, Germany; c Department of Surgery, NTNU - St. Olavs Hospital, Olav Kyrres gate 17, 7006 Trondheim, Norway; d Department of Circulation and Medical Imaging, Norwegian University of Science and Technology 7489 Trondheim, Norway; ABSTRACT In the current clinical workflow of minimally invasive aortic procedures navigation tasks are performed under 2D or 3D angiographic imaging. Many solutions for navigation enhancement suggest an integration of the preoper- atively acquired computed tomography angiography (CTA) in order to provide the physician with more image information and reduce contrast injection and radiation exposure. This requires exact registration algorithms that align the CTA volume to the intraoperative 2D or 3D images. Additional to the real-time constraint, the reg- istration accuracy should be independent of image dissimilarities due to varying presence of medical instruments and contrast agent. In this paper, we propose efficient solutions for image-based 2D-3D and 3D-3D registration that reduce the dissimilarities by image preprocessing, e.g. implicit detection and segmentation, and adaptive weights introduced into the registration procedure. Experiments and evaluations are conducted on real patient data. Keywords: Registration, Image-Guided Therapy, Intraoperative imaging, Procedures. 1. DESCRIPTION OF PURPOSE The implantation of an endovascular stent graft inside the aorta is a minimally-invasive procedure for the treat- ment of aortic aneurysms and aortic dissections. After the insertion of a pigtail catheter and guide wires, a shaft catheter including a folded stent graft is placed inside the aneurysm or dissection. Before unfolding the stent graft, the physician must ensure that branching vessels are not occluded. In this stage, misplacements of the stent graft can certainly lead to partial or total cut-offs of blood supply of vitally important organs and will lead to a life-threatening emergency surgery. The entire interventional catheter navigation is done under 2D angiography imaging where the physician is miss- ing the important 3D information. As the catheter and stent position is only visualized in plane, more image acquisitions are needed during fine positioning of the stent graft before unfolding. This means an increase in radiation dose and used contrast agent at the same time as branching vessels need to be made visible in the Further author information: (Send correspondence to S.D.) S.D.: E-mail: demirci@cs.tum.edu O.K.: E-mail: kutter@cs.tum.edu F.M.: E-mail: frode.manstad.hulaas@ntnu.no R.B.: E-mail: bauernschmitt@dhm.mhn.de N.N.: E-mail: navab@cs.tum.edu Medical Imaging 2008: Visualization, Image-guided Procedures, and Modeling, edited by Michael I. Miga, Kevin Robert Cleary, Proc. of SPIE Vol. 6918, 69182S, (2008) 1605-7422/08/$18 · doi: 10.1117/12.769835 Proc. of SPIE Vol. 6918 69182S-1 2008 SPIE Digital Library -- Subscriber Archive Copy