Improved Bronchoscopy by new image guided Approach

Abstract

Navigation in bronchoscopy has developed into a feasible approach for lung diagnostics since introduced in 1998. The concept combines computer generated models from patient CT data with position and orientation tracking of the bronchoscope tip and/or other tools. Trials using navigational bronchoscopy have demonstrated increased diagnostics success rates. Despite higher diagnostic success rates and two decades of development in navigation for bronchoscopy, the use of the technology is still not common in lung diagnostics. The pulmonologist is trained surveying and assessing CT and steering via video display from a flexible scope during bronchoscopy. Expanding the conventional work with additional display through techniques such as navigational bronchoscopy can be expensive to integrate in smaller hospitals and complicated for pulmonologists without proper training. Also, existing VB approaches only offers endoluminal view, an airway segmentation as a “road map” to lesions in lungs, and in best circumstances additional models of segmented lesions and vessels. New solutions specifically for bronchoscopy visualization application was developed in this project. This thesis presents a development and evaluation of a new visualization approach for planning and guidance in bronchoscopy; Anchored to Centerline Curved Surface (ACCuSurf), consisting of more complete view for navigated bronchoscopy in tube-like structures. The technique may also be combined with other methods such as VB, PET and ultrasound images, by adding these data sources to the display. At the same time as providing overview of the lungs and tools, the ACCuSurf can be zoomed in and show more anatomical details than the conventional endoluminal view. First, a comparison of different approaches to airway segmentation was carried out to establish a route to target. Secondly, the ACCuSurf was developed by slicing the segmented airways in half, creating a 3D volume representing surrounding anatomy along the path to target. Finally, the ACCuSurf method was assessed by pulmonologists using it as a planning tool before performing bronchoscopy on a phantom with a mixed data set from a patient and the phantom. The conventional 2D (axial, sagittal, coronal) visualisation was comparison reference. The study is an effort to ease and simplify visualisation for navigation in bronchoscopy.