Optical coherence tomography: Advanced technology for the endoscopic imaging of Barrett's esophagus

Background and Study Aims: Endoscopic optical coherence tomography (OCT) is an emerging medical technology capable of generating high-resolution cross-sectional imaging of tissue microstructure in situ and in real time, We assess the use and feasibility of OCT for real-time screening and diagnosis of Barrett's esophagus, and also review state-of-the-art OCT technology for endoscopic imaging. Materials and Methods: OCT imaging was performed as an adjunct to endoscopic imaging of the human esophagus, Real-time OCT (13-mum resolution) was used to perform image-guided evaluation of normal esophagus and Barrett's esophagus, Beam delivery was accomplished with a l-mm diameter OCT catheter-probe that can be introduced into the accessory channel of a standard endoscope, Different catheter-probe imaging designs which performed linear and radial scanning were assessed, Novel ultrahigh-resolution (1.1 mum resolution) and spectroscopic OCT techniques were used to image in vitro specimens of Barrett's esophagus. Results: Endoscopic OCT images revealed distinct layers of normal human esophagus extending from the epithelium to the muscularis propria, In contrast, the presence of gland- and crypt-like morphologies and the absence of layered structures were observed in Barrett's esophagus, All OCT images showed strong correlations with architectural morphology in histological findings, Ultrahigh-resolution OCT techniques achieved 1.1 mum image resolution in in vitro specimens and showed enhanced resolution of architectural features. Spectroscopic OCT identified localized regions of wavelength-dependent optical scattering, enhancing the differentiation of Barrett's esophagus. Conclusions: OCT technology with compact fiberoptic imaging probes can be used as an adjunct to endoscopy for real-time image-guided evaluation of Barrett's esophagus. Linear and radial scan patterns have different advantages and limitations depending upon the application, Ultrahigh-resolution and spectroscopic OCT techniques improve structural tissue recognition and suggest future potential for resolution and contrast enhancements in clinical studies, A new balloon catheter-probe delivery device is proposed for systematic imaging and screening of the esophagus.