In Vivo 3D Comprehensive Microscopy of the Human Esophagus for the Management of Barrett's Patients

Abstract

Optical coherence tomography (OCT) provides high-resolution (∼10 μm resolution) cross-sectional images of esophageal microstructure and in recent years has been shown to accurately differentiate specialized intestinal metaplasia (SIM) from gastric cardia at the squamocolumnar junction for screening, and diagnose dysplasia and cancer in patients with SIM for surveillance of Barrett's esophagus. The clinical utility of this technology has however been restricted due to limitations in imaging speed and optical probe design. Optical frequency domain imaging (OFDI) is a new imaging technology that is capable of improving imaging speed over traditional OCT techniques by orders of magnitude without sacrificing image quality. We have developed a balloon catheter (2.5 cm dia.) based OFDI system that acquires comprehensive three-dimensional microscopic images of the entire distal esophagus (∼6.0 cm) with resolution in cylindrical coordinates of 20 μm (φ) × 8 μm (r) × 50 μm (z) in < 2 mins. Comprehensive microscopy of the distal esophagus was performed in over 40 patients with the OFDI system and balloon catheter. The acquired volumetric OFDI datasets were assessed and correlated to histopathological findings. For the 40 patients, we achieved satisfactory imaging in 37 patients (92%) and an average of over 90% surface area coverage per patient. Based on these early results, we anticipate that comprehensive volumetric microscopy with OFDI will provide a minimally invasive means for screening the entire distal esophagus for intestinal metaplasia, dysplasia, and adenocarcinoma.