Virtual endoscopy (VE) is an integration of medical imaging and virtual reality. VE gives a computer-based alternative to standard radiological image viewing and to traditional fiber optic endoscopy for examining the interior structures of human organs. Unlike traditional fiber optic endoscopy, which is confined to the interior of a hollow organ, VE enables navigation between the inner and outer mucosal layers. VE has many advantages, such as being less invasive, cost-effective, free of risks and side effects. VE is ideal for screening purposes and surgical planning. VE involves three major steps: 1) organ segmentation, 2) flight path generation, and 3) rendering of the organ’s internal views. The computation of 3D flight paths of volumetric objects is still a challenging process due to the complex nature of the anatomical structures.
The aim of this project is to build a general virtual endoscopy system for screening hollow organs such as carotid, aorta, tracheobronchial trees, spine, and colon. 
Research Team Aly A. Farag CVIP Director farag@cvip.louisville.edu M. Sabry Hassouna Research Assistant msabry@cvip.louisville.edu 
Methods
Virtual Endoscopy involves 3 steps: segmentation, flight path generation, and visualization of the internal views of the anatomical structures. In this project, we focus on the last two steps. In the first phase of this project, we propose a general framework for computing flight paths of tubular anatomical structures for virtual endoscopy applications using level set methods. The new technique works in two passes. In the first pass, the overall topology of the organ is analyzed and its important topological nodes are identified, while in the second pass, the actual flight paths are computed by tracking them starting from each identified node. The proposed framework is robust, fully automatic, computationally efficient, and computes CS that are centered, connected, thin, and less sensitive to boundary noise. We have extensively validated the robustness of the proposed method both quantitatively and qualitatively against several synthetic phantoms and clinical datasets.
Results
Virtual Angioscopy in Aorta
Virtual Bronchoscopy
Virtual Colonoscopy
Movies
Colon Fly-Through (Part1)
Colon Fly-Through (Part 2)
Trachea Fly-Through
Publications
1. M. Sabry Hassouna and A.A. Farag, “PDE-Based Three Dimensional Path Planning For Virtual Endoscopy,” Proc. of Information Processing in Medical Imaging 2005 (IPMI’05), Glenwood springs, Colorado, USA, July 2005. To appear.
2. M. Sabry Hassouna, A.A. Farag, “3D Path Planning For Virtual Endoscopy,” Proc. of Computer Assisted Radiology and Surgery (CARS’05), Berlin, Germany, June 22-25, 2005, to appear.
Acknowledgement / Sponsors
We would like to thank the University of Louisville for its sponsorship.
CVIP Lab 