Reliable navigation for virtual endoscopy

Virtual endoscopy provides a computerized, non-invasive procedure for detecting anomalies inside human organs. Several preliminary studies have demonstrated the benefits and effectiveness of such a modality. Unfortunately, previous work can not guarantee that an existing anomaly be detected, and it does not provide an effective navigation method for examining complex organs with multiple branches. Here, the authors introduce the concept of reliable navigation that ensures the interior organ surface is fully examined by the physician performing the virtual endoscopy procedure. To achieve this, the authors first locate inside the hollow organ a small set of center observation points. For each observation point, there exists at least one patch of interior surface visible to it that can not be seen from any of the other observation points. The authors then link these chosen points with a path that stays in the center of the organ. Finally, they recursively select new points inside the organ and connect them into the path until the entire organ surface is visible from the path. During the navigation, the physician´s movement is restricted to this automatically computed path, while he can use an intuitive and zoomable camera to explore the surface detail. The authors present an encouraging result from their experiments on an airway data