Wahle A, Prause GPM, DeJong SC, Sonka M:


A Comprehensive Method for Geometrically Correct 3-D Reconstruction of Coronary Arteries by Fusion of Intravascular Ultrasound and Biplane Angiography.

In:

Doi K, MacMahon H, Giger ML, Hoffmann KR (eds):

Computer-Aided Diagnosis in Medical Imaging.

Proceedings of the First International Workshop on Computer-Aided Diagnosis, Chicago IL, Excerpta Medica International Congress Series, Elsevier

Volume 1182, Page 363-368, 1998/99

Overview about the system for fusion of biplane angiograms and IVUS images (Journal) (Paper) (Images)

Abstract: In the rapidly evolving field of intravascular ultrasound (IVUS), assessment of spatial structures still lacks a geometrically correct 3-D reconstruction. The IVUS frames are usually stacked up to form a straight vessel, neglecting curvature and the axial twisting of the catheter during the pullback. Quantification of this simplified data inevitably results in significantly distorted values.

Our method combines the knowledge about vessel cross-sections obtained from IVUS with the knowledge about the vessel geometry derived from biplane angiography. First, the catheter path is reconstructed from its biplane projections, resulting in a spatial model that already contains sufficient information to determine the location of the IVUS frames as well as their orientation relative to each other. Locations are derived from the time function, which implies the use of an automatic pullback device. Catheter twisting is calculated using a discrete version of the Frenet-Serret rules known from differential geometry. Our method uses the bending behavior of the catheter as reference for the absolute frame orientation along the pullback path. IVUS segmentation is performed with our previously developed algorithm.

The approach has been extensively validated in computer simulations as well as in phantoms and cadaveric pig hearts. An in-vivo application is under way. The algorithms showed good accuracy in determining the location and relative twist even in complex catheter paths and under noisy conditions. The computer models ranged from simple sets of arcs over helices to free-shaped catheter paths. In the in-vitro studies, distortions due to manual pullback or catheter mechanics could be determined.