Project Summary The overall objective of this research project is to develop a low cost implementation of spectroscopic optical coherence tomography (SOCT) for the purpose of evaluating colonic polyps or tissues during colonoscopy procedures. According to current standard of care, colonic polyps are removed by the endoscopist, and then fixed, stained and sectioned before being diagnosed by a pathologist. Here we propose to use SOCT to allow the physician to better identify potentially precancerous polyps or tissues during the endoscopic procedure. To meet this objective, we propose to create an OCT system suitable for use during colonoscopy based on Lumedica’s proprietary OCT engine technology. Lumedica’s OCT systems are designed to provide high performance at low cost but also enable easily configurable parameters, such as imaging speed, imaging resolution and depth. For this project a novel scanning probe will be designed that can be deployed during colonoscopy, and yet is inexpensive enough to be single-use, i.e. disposable. The probe will also be designed to fit in with the standard workflow of endoscopy. Instead of requiring the use of the biopsy channel of the colonoscope for access, the low cost OCT GI probe will be affixed to the outer housing of the endoscope, allowing the physician to examine regions of interest and then acquire a biopsy or remove a polyp without removing the OCT probe. Finally, we will extend clinical utility by expanding the spectral range of the low cost OCT system to permit use of SOCT to obtain functional information by quantitatively analyzing the scattering and absorption properties of the tissue as a means to improve diagnosis. To achieve this goal, we propose the following specific aims: 1) Instrument development: We will implement a new OCT instrument for examination of colorectal polyps with potential for commercial translation to clinical use. The instrument will include a low cost OCT engine, upgraded to enable spectroscopic OCT measurements and a novel probe design that is sufficiently inexpensive to be single use. The probe design will be different from previous OCT efforts, using an approach which fits into the endoscopic workflow by avoiding the need to insert and retract the probe for measurements. 2) SOCT tissue studies: The new SOCT instrument will be applied to examination of resected colon polyps to identify optical spectroscopic signatures of pre-malignancy or adenomas. The probe will be also be applied during endoscopic procedures to validate its ability to interface with the colonic mucosa while also permitting a collocated biopsy to be acquired. Achieving these specific aims will demonstrate feasibility of low cost SOCT for evaluating colorectal epithelial tissues and provide justification for further commercial development.