Above: 3D vessels segmented from CTA and registered with x-ray angiograms. Black arrow points to balloon used for registration updates. White arrow points to colored, 3D vessels. Right: Andrei State's drawing of the visualization setup.

Supported by NIH-HLB R01 HL69808

Endovascular surgery involves inserting a catheter (tube) into a major artery or vein, and then threading that catheter through a vascular network to a target region. Therapy can then be delivered through the catheter. One of the difficulties with endovascular operations is that the procedure is guided by flat, projection images that show only the connected vasculature downstream of the catheter tip.

We have developed methods of registering 3D vessel trees with 2D x-ray angiograms and of reconstructing the interventionalist's catheter into 3D from pairs of projection views. The procedure can then be performed with the advantage of 3D information.

An application under active development is for TIPS (transthoracic, intrahepatic, portosystemic shunt formation), in which the interventionalist pushes a needle through the liver into a portion of the vasculature he cannot visualize. Registration updates are provided by tracking an ovoid balloon catheter seen on the two projection views. Three-dimensional visualizations will be provided by stereo projection display.

This work also requires methods of extracting and tracking in real time both the clinician's needle and the balloon catheter as seen on intraoperative projection views. Click for more details on <needle tracking> .

A major challenge has been accurate, fast, 3D-2D vessel registration under conditions in which the input 2D images contain extraneous wires and are sometimes of execrable quality. We view solution to this problem as one of the major contributions of this project, and are currently approaching it by a model-to-image vessel registration approach.

Bullitt E, Liu A, Pizer SM (1997) Three dimensional reconstruction of curves from projection views. II. Analysis of error. Medical Physics 24:1679-87. <pdf>

Liu A, Bullitt E, Pizer SM (1998) 3D/2D registration using tubular anatomical structures as a basis. MICCAI '98, Lecture Notes in Computer Science 1496: 952-963.

Jolly B, Van Horn M, Aylward S, Bullitt E (2003) Needle tracking and detection in the TIPS endovascular procedure MICCAI 2003. LNCS 2878:953-954. <pdf>.

Venkatraman V, Van Horn M, Weeks S, Bullitt E (2004) Liver Motion Due to Needle Pressure, Cardiac and Respiratory Motion During the TIPS Procedure. MICCAI 2004; Lecture Notes in Computer Science 3217:66-72 <pdf>.

Maupu D, Van Horn M, Weeks S, Bullitt E (2005) 3D stereo interactive visualization for the TIPS procedure. IEEE Computer Graphics and Applications 25:67-71 <pdf>.

Pathak C, Van Horn M, Weeks S, Bullitt E (2005) Comparison of simultaneous and sequential two-view registration for 3D/2D registration of vascular images. MICCAI 2005; LNCS 3750:239-246.<pdf>

Jomier J, Bullitt E, Van Horn M, Aylward SR. 3D/2D Model-to-image registration applied to TIPS surgery. Jomier J, Bullitt E, Van Horn M, Pathak C, Aylward S (2006) MICCAI 2006; LNCS 4191:662-669. <pdf>