First results of endoscopic applications of optical coherence tomography for in vivo studies of human mucosa in respiratory, gastrointestinal, urinary and genital tracts are presented. A novel endoscopic OCT (EOCT) system has been created that is based on the integration of a sampling arm of an all-optical-fiber interferometer into standard endoscopic devices using their biopsy channel to transmit low-coherence radiation to investigated tissue. We have studied mucous membranes of esophagus, larynx, stomach, urinary bladder, uterine cervix and body as typical localization for carcinomatous processes. Images of tumor tissues versus healthy tissues have been recorded and analyzed. Violations of well-defined stratified healthy mucosa structure in cancered tissue are distinctly seen by EOCT, thus making this technique promising for early diagnosis of tumors and precise guiding of excisional biopsy.

We use optical coherence tomography (OCT) to perform a comprehensive program of in vivo and in vitro structural imaging of hard and soft tissues within the oral cavity. We have imaged the different types of healthy oral mucosa as well as normal and abnormal tooth structure. OCT is able to differentiate between the various types of keratinized and non-keratinized mucosa with high resolution. OCT is also able to provide detailed structural information on clinical abnormalities (caries and non-caries lesions) in teeth and provide guidance in dental restorative procedures. Our investigations demonstrate the utility of OCT as a diagnostic imaging modality in clinical and research dentistry.

Background and Study Aims: Optical coherence tomography (OCT) is a new technique for high-resolution cross-sectional imaging using infrared light. It has over 10 times the resolution of the currently available ultrasonography. Although in vitro studies have suggested its potential for gastrointestinal imaging, in vivo studies have not been possible so far on account of technical limitations. Patients and Methods: We describe here the first clinical study of OCT during routine endoscopy obtaining high resolution images of the normal esophageal, gastric, and colonic mucosa. Portable OCT equipment and a fiberoptic-based flexible probe for endoscopic use have been developed by the authors. Results: Differences in the optical properties of epithelium, lamina propria, muscularis mucosae, and submucosa enabled distinction of the mucosal architecture. Owing to the low penetration depth (1 mm) and high resolution (10 μm), OCT images may become comparable to mucosal histological findings. Image acquisition time was 1.5 seconds, and the entire procedure was completed within 5 minutes. Endoscopic OCT images of colonic adenoma and carcinoma were also studied and compared with the corresponding histology. Conclusions: The newly developed portable OCT equipment and flexible fiberoptic probe makes OCT a promising method for endoscopic “optical biopsy”.

Initial data, capabilities and limitations conclusions, and diagnostic usefulness recommendations derived from application of our endoscopic optical coherence tomography (EOCT) system to the imaging of the mucous membranes of human internal organs are presented herein based on in vivo study of more than 100 patients. These data suggest that EOCT can provide, non-invasively and innocuously, such significant clinical diagnostic information as the following: identification and localization of informative internal biopsy sites; structural characterization of normal and abnormal internal mucosal tissues; guidance in the rendering of surgical and non-surgical treatments; and monitoring of the functional states (both normal and abnormal) of internal orgarns and post-operative recovery processes in the same. This investigation demonstrated that OCT data is more informative for organs with epithelial tissues separated from their underlying stroma by a smooth basal membrane; therefore, this report focuses on the EOCT study of three such internal organs - the larynx, the bladder, and the uterine cervix. Additionally reported herein, for the first time, is the laparascopic OCT examination of the mucosal lining of the abdomen.

Background and Study Aims: We studied the feasibility of endoscopic optical coherence tomography imaging in esophageal disorders, including Barrett's esophagus and Barrett-related adenocarcinoma. Optical coherence tomography is a high-resolution cross-sectional imaging technique with a resolution of almost 10 μm. Patients and Methods: The mucosal architecture of reflux esophagitis (n = 9) and Barrett's esophagus (n = 9) including Barrett-related esophageal cancer (n = 6) was studied by optical coherence tomography imaging. Results: In different stages of reflux esophagitis edema, fibrinoid deposits, or loss of the epithelial layer were observed. Optical coherence tomography images of Barrett's esophagus substantially differed from normal esophagus, reflux esophagitis, and esophageal carcinoma. A stratified structure of the mucosa was still preserved in Barrett's esophagus. However, images of Barrett-related cancer lacked the regular structure of the esophagus. Conclusions: The high consistency of the first optical coherence tomography findings, the resolution of up to 10 μm, and the distinct pattern of normal, inflammatory, premalignant and malignant tissues make optical coherence tomography a promising method for endoscopically obtained optical biopsy.