Interactive path planning for virtual endoscopy [colon CT]

Virtual colonoscopy has been developed as a non-invasive computerized medical procedure for examining the entire colon to detect polyps. The authors´ group has successfully implemented an interactive navigation using a physically-based camera control model and a hardware-assisted visibility algorithm. Unfortunately, the pre-processing (skeleton and potential field generations) consumes too much computing time to be acceptable in an interactive environment. In this work, the authors focus on skeleton simplification to eliminate excessive ramification. They perform the simplification before the skeleton generation. The idea is to utilize a hierarchical analysis of attractors to determine principal attractors. The authors also propose a dynamic target navigation for virtual endoscopy. They combine potentials derived from the distance between source and target positions and from the distance to the colon surface to guide path search processes. These potentials are essential to obtain priority in choosing the paths far away from colon wall and in the direction of target positions