Guidance system development for radial-probe endobronchial ultrasound bronchoscopy

For peripheral pulmonary lesion diagnosis, surgical thoracoscopy and percutaneous needle biopsy are common invasive options, but entail significant risks; e.g., percutaneous biopsy carries a 15% pneumothorax rate and risk of other complications. The development of new bronchoscopic devices, such as radial-probe endobronchial ultrasound (RP-EBUS), however, enables far less risky lesion diagnosis. Based on recent research, an image-guided bronchoscopy system can be used to navigate the bronchoscope close to the lesion, while RP-EBUS, which provides real-time extraluminal information on local tissue and lesions, can then be used for lesion localization and biopsy site selection. Unfortunately, physician skill in using RP-EBUS varies greatly, especially for physicians not at expert centers. This results in poor biopsy yields. Also, current state-of-the-art image-guided bronchoscopy systems provide no means for guiding the use of the RP-EBUS. We describe progress toward devising a methodology that facilitates synchronization of the known chest CT-based guidance information to possible locations for invoking RP-EBUS. In particular, we describe a top-level CT-based mechanism that mimics the possible positions of the RP-EBUS probe, supplemented with an approach that simulates possible RP-EBUS views. Results with human patient data demonstrate the potential of the methodology.