| Barrett's esophagus (BE) surveillance remains challenging, because even histopathology, the gold standard, is subject to sampling error. The esophageal mucosal area involved in BE can be 20 cm2 or more. 3-D volumetric Imaging technology with high diagnostic accuracy may potentially guide and assist the standard histopathology, eliminate the sampling error and improve surveillance efficiency. It has been shown that endoscopic optical coherence tomography (EOCT) of a small mucosal area can obtain interpretable images of gastro-intestinal mucosal microstructure, differentiate mucosal types and detect dysplasia in Barrett's esophagus. The realization of 3-D EOCT allows for further exploring the potential to fulfill the unmet need of comprehensive surveillance. The dissertation presents the step-by-step work from initially building the 3-D EOCT system for esophageal imaging, to eventually conducting the clinical trial. First, a system based on a spectral-domain OCT configuration will be described. The sample arm with the rotary-joint-pullback unit, double-balloon-based catheter and miniature fiber-optic probe is the main hardware innovation allowing for 3-D imaging. Second, an automated motion artifact correction algorithm will be described. The algorithm successfully reveals the otherwise distorted microstructure in the esophageal mucosa, such as microvasculature network and the layered structure. The feasibility of 3-D imaging and motion artifact correction algorithm will be demonstrated in swine in vivo. Third, the balloon designs will be discussed in terms of safety and diagnostic efficiency for clinical trial. It will be shown that a low pressure level is sufficient for motion artifact suppression, and therefore reduce the risk of perforation. Images appearance is significantly influenced by balloon pressure/contact, which establishes the need to image the mucosa with the double-balloon design. Finally, the first cases in clinical trial of BE patients will be reported. The feasibility of 3-D EOCT imaging system are demonstrated. Images features such as layered structure, surface morphology and glandular structure are observed in BE patients. The 3-D EOCT system provides a platform allowing for comprehensive imaging in high quality, which can potential answer critical questions about what role OCT can play in dysplasia diagnosis during BE screening/surveillance. |
