Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2013.Cataloged from PDF version of thesis.Includes bibliographical references.Optical coherence microscopy (OCM) combines optical coherence tomography (OCT) with confocal microscopy and enables depth resolved visualization of biological specimens with cellular resolution. OCM offers a suitable alternative to confocal imaging by providing enhanced contrast due to the additional coherence gate to the inherent confocal gate, increasing the field of view and imaging depth, and eliminating the need of external contrast agents. In the past, development of OCT systems have been focused on time domain and spectral/Fourier domain methods which offer high axial resolution and imaging speeds. However, recent advances in the OCT technology have pushed the development into the direction of swept source OCT technologies, and development of the OCM technology is likely to follow this path. This thesis describes construction, characterization and preliminary imaging results of a swept source OCM (SS-OCM) system utilizing a novel light source, Vertical Cavity Surface-Emission Laser (VCSEL). This swept source laser can reach sweep rates exceeding 1 MHz and provide wide tuning ranges, which will enable both imaging speeds approaching to time domain OCM (TD-OCM) systems, and axial resolution approaching to spectral/Fourier domain OCM (SD-OCM) systems. Several other advantages of SS-OCM compared to TD-OCM and SD-OCM that make this technology a promising alternative to the latter imaging methods are presented. Furthermore, practical concepts in the system development and signal processing, such as compensation for the scan curvatures, methods for calibration of the spectrums, selection of suitable color maps for display, and other related topics are also discussed in the text. In addition to technical description of the OCM system development, an in depth analysis of several clinical applications that will be likely to benefit from this imaging modality is also presented. Real time intraoperative feedback is required in order to reduce the morbidity and the rate of additional operations for the surgical management of several forms of cancer, where a benchtop OCM system residing in the pathology laboratory can be immensely beneficial. Furthermore, with the novel scanning mechanisms that have been developed in the recent years it is possible to translate this imaging modality to an in vivo setting where an OCM probe can be inserted through the working channel of an endoscope and generate cellular resolution images in real time without the need of external contrast agents. Endoscopic management and clinical challenges for a spectrum of lower gastrointestinal (GI) diseases is discussed where an in vivo OCM imaging probe can play an important role in the diagnosis and evaluation of the extend of the particular disease. A review of alternative imaging modalities, such as chromoendoscopy, narrow band imaging (NBI) and confocal laser endomicroscopy (CLE) is also included which outlines the relative strengths and limitations of these imaging modalities for the clinical management of lower GI diseases.by Osman Oguz Ahsen.S.M
