To diagnose peripheral lung tumors, bronchoscopy is recommended for tissue sampling. Because most peripheral target regions of interest reside outside the airways, during bronchoscopy radial probe endobronchial ultrasound (RP-EBUS) is often used to provide extraluminal information and assist in locating biopsy sites. RP-EBUSguided transbronchial needle aspiration (TBNA) has demonstrated its potential over conventional TBNA to improve the diagnostic yield of peripheral pulmonary nodule biopsy. Meanwhile, image-guided bronchoscopy systems have been introduced to enable better planning and navigation. Currently, the physician has to deal with two disconnected imaging domains during live bronchoscopy; i.e., an image-guided system and RP-EBUS. The state-of-the-art image-guided bronchoscopy systems provide no guidance for RP-EBUS and biopsy targeting during live bronchoscopy, which is needed for accurate diagnosis of peripheral pulmonary nodules. To fill this gap, we expand the concept of virtual bronchoscopy (VB) in image-guided bronchoscopy systems and build a virtual RP-EBUS model to simulate the RP-EBUS probe in the computed-tomography (CT)-based virtual chest space. Results with human patient data illustrate the synchronized visualization of the virtual RP-EBUS model with the 3D chest model.
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.