Ultrahigh resolution optical coherence tomography of Barrett's esophagus: preliminary descriptive clinical study correlating images with histology

Background and study aims: Endoscopic ultrahigh resolution optical coherence tomography (UHR OCT) achieves an axial image resolution of similar to 5 pm, which is 2 - 3 times finer than standard endoscopic OCT imaging. This study investigated the capability of endoscopic UHR OCT for imaging patients with Barrett's esophagus. Patients and methods: Fivty volunteers previously diagnosed with Barrett's esophagus underwent UHR OCT. Imaging was performed at 1.3 mu m wavelengths with - 5 pm axial and - 15 pm transverse resolutions using a 1.8 mm/ diameter linear-scanning catheter introduced through the accessory channel of a standard endoscope. OCT images were compared with endoscopic diagnosis and pinch biopsy histological appearances. Results: UHR OCT images of normal esophagus, Barrett's esophagus, high grade dysplasia and esophageal adenocarcinoma were evaluated. UHR OCT images of the normal esophagus exhibited characteristic layered architecture with uniform epithelium, while images of Barrett's esophagus corresponded to crypt-like glandular structures. High grade dysplasia and esophageal adenocarcinoma images exhibited more heterogeneous structures corresponding to irregular, heterogeneous tissue morphology from distorted and cribriform or villiform glandular architecture. Fine features can be discerned more clearly with endoscopic UHR OCT. Conclusions: This study evaluated new endoscopic OCT technology and demonstrated the feasibility of carrying out UHR OCT imaging in conjunction with standard endoscopy for in vivo real-time imaging of Barrett's esophagus, dysplasia, and esophageal adenocarcinoma. A survey of normal and abnormal upper gastrointestinal tissues was performed using a research prototype OCT system with the highest axial resolution to date, and can serve as a baseline for future inves-