Image-based bronchoscopy navigation system based on CT and C-arm fluoroscopy

Lung cancer diagnosis requires biopsy of airway tissue, which is mostly done by bronchoscopy. Although preoperative CT is available, intraoperatively only 2D information provided by the bronchoscopic camera and fluoroscopy is used. But, guidance of the bronchoscope to the target site would highly benefit from knowing the exact 3D position of the instrument inside the airways. In this paper, we present a system for preoperative planning and intraoperative navigation during bronchoscopy. The preoperative components are automatic bronchial tree segmentation and skeletonization, semi-automatic tumor segmentation and a virtual fly-through simulation for planning purposes. During the intervention, we apply C-arm pose estimation using a marker plate on the patient table to align preoperative CT and intraoperative fluoroscopy. Thus, we can calculate the current 3D position of the bronchoscope inside the bronchial tree. Evaluation of the system components on patient CT and phantom fluoroscopy images showed promising results with high accuracy and robustness.