Comprehensive esophageal microscopy by using optical frequency-domain imaging (with video)

Background: Optical coherence tomography (OCT) has been used for high-resolution endoscopic imaging and diagnosis of specialized intestinal metaplasia, dysplasia, and intramucosal carcinoma of the esophagus. However, the relatively slow image-acquisition rate of the present OCT systems inhibits wide-field imaging and limits the clinical utility of OCT for diagnostic imaging in patients with Barrett's esophagus. Objective: This study describes a new optical imaging technology optical frequency-domain imaging (OFDI), derived from OCT, that enables comprehensive imaging of large esophageal segments with microscopic resolution. Design: A prototype OFDI system was developed for endoscopic imaging. The system was used in combination with a balloon-centering catheter to comprehensively image the distal esophagus in swine. Results: Volumetric images of the mucosa and portions of the muscularis propria were obtained for 4.5-cm-long segments. Image resolution was 7 mu m in depth and 30 mu m parallel to the lumen, and provided clear delineation of each mucosal layer. The 3-dimensional data sets were used to create cross-sectional microscopic images, as well as vascular maps of the esophagus. Submucosal vessels and capillaries were visualized by using Doppler-flow processing. Conclusions: Comprehensive microscopic imaging of the distal esophagus in vivo by using OFDI is feasible. The unique capabilities of this technology for obtaining detailed information of tissue microstructure over large mucosal areas may open up new possibilities for improving the management of patients with Barrett's esophagus.