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 as sess the use and feasibility of OCT for real-time screening and diagnosis o f 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 endoscopi c imaging of the human esophagus, Real-time OCT (13-mum resolution) was use d to perform image-guided evaluation of normal esophagus and Barrett's esop hagus, Beam delivery was accomplished with a l-mm diameter OCT catheter-pro be that can be introduced into the accessory channel of a standard endoscop e, Different catheter-probe imaging designs which performed linear and radi al scanning were assessed, Novel ultrahigh-resolution (1.1 mum resolution) and spectroscopic OCT techniques were used to image in vitro specimens of B arrett's esophagus. Results: Endoscopic OCT images revealed distinct layers of normal human eso phagus extending from the epithelium to the muscularis propria, In contrast , the presence of gland- and crypt-like morphologies and the absence of lay ered 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 op tical scattering, enhancing the differentiation of Barrett's esophagus. Conclusions: OCT technology with compact fiberoptic imaging probes can be u sed as an adjunct to endoscopy for real-time image-guided evaluation of Bar rett's esophagus. Linear and radial scan patterns have different advantages and limitations depending upon the application, Ultrahigh-resolution and s pectroscopic OCT techniques improve structural tissue recognition and sugge st future potential for resolution and contrast enhancements in clinical st udies, A new balloon catheter-probe delivery device is proposed for systema tic imaging and screening of the esophagus.