ABSTRACT Bile duct strictures can lead to painful clinical symptoms and can be caused by a wide range of conditions from benign diseases to cholangiocarcinoma, a deadly cancer of the bile duct with 5-year survival rates as low as 2% for late stage disease. The management and prognosis of bile duct strictures varies significantly, so accurate diagnosis and differentiation between malignant and benign strictures is critical. Currently the most common way to differentiate a biliary stricture is to perform biopsy or brush cytology with the use of endoscopic retrograde cholangiopancreatography (ERCP). However, the diagnostic yield is low due to small tissue sampled with limited image guidance. Endoscopic optical coherence tomography (OCT) provides wide field imaging of the surface and subsurface tissue microstructure, and has been previously evaluated for use in the biliary system with promising results. The goal of this project is to develop and evaluate a single device to perform precise image guided biopsy within the biliary system. Here, we will combine OCT to visualize abnormalities over a wide field of view to provide high disease sensitivity, along with an integrated tissue acquisition tool for pathological confirmation of abnormalities to provide high specificity. In aim 1, we will develop a prototype miniaturized and flexible OCT probe with integrated tissue acquisition, enabling precise image guided biopsy. Aim 2 is to evaluate the feasibility of this tool in a simulated biliary model to acquire tissue samples under image guidance and verify the one-to-one co-registration.