Diagnosis of specialized intestinal metaplasia by optical coherence tomography.

BACKGROUND AND AIMS: Optical coherence tomography (OCT) is an imaging technique that produces high-resolution cross-sectional images in vivo. The aim of this study was to establish the sensitivity and specificity of OCT for diagnosing specialized intestinal metaplasia (SIM). METHODS: OCT was used to image the stomach and esophagus of 121 patients. A total of 288 biopsy-correlated OCT images were acquired. OCT criteria for SIM were formulated by analyzing 75 images of SIM. The SIM image criteria were retrospectively tested by applying them to images of gastric, squamous, SIM, and cardiac epithelium. The criteria were then tested prospectively to determine the sensitivity and specificity of OCT for diagnosing SIM. RESULTS: OCT images of SIM are characterized by (1) absence of the layered structure of normal squamous epithelium and the vertical "pit and crypt" morphology of gastric mucosa, (2) disorganized architecture with inhomogeneous tissue contrast and an irregular mucosal surface, and (3) presence of submucosal glands. These criteria were 100% sensitive and 93% specific for SIM when applied retrospectively and 97% sensitive and 92% specific when tested prospectively. CONCLUSIONS: OCT is highly sensitive and specific for SIM and may aid in the diagnosis and surveillance of this preneoplastic lesion.

Optical coherence tomography in the gastrointestinal tract.

Optical coherence tomography (OCT) is a high-resolution, cross-sectional optical imaging technique that allows in situ imaging of tissue by measuring back-reflected light. OCT provides images in real time with a resolution approaching that of conventional histopathology, but without the need for tissue removal. OCT imaging can be performed endoscopically to visualize gastrointestinal tissue using a fiberoptic catheter passed through the instrument channel of a conventional endoscope. The resolution of OCT allows visualization of the different layers of gastrointestinal epithelium and the differentiation of Barrett's epithelium from normal gastric and squamous mucosa. OCT has also been used to image esophageal adenocarcinoma and colonic polyps. Recent developments include Doppler OCT, spectroscopic OCT, and ultrahigh-resolution OCT, which can visualize nuclei within single cells. Although still in its infancy as a clinical tool, OCT currently provides high-resolution images over the same imaging depth as conventional mucosal biopsy, and may prove to be a useful and minimally invasive technique for evaluating gastrointestinal tissue, particularly for early neoplastic changes.