Ultrahigh resolution endoscopic optical coherence tomography for gastrointestinal imaging

Optical coherence tomography (OCT) is an emerging medical imaging technology which can generate high resolution, cross-sectional images of tissue in situ and in real time, without the removal of tissue specimen. Although endoscopic OCT has been used successfully to identify certain pathologies in the gastrointestinal tract, the resolution of current endoscopic OCT systems has been limited to 10- 15 mu m for clinical procedures. In this study, in vivo imaging of the gastrointestinal tract is demonstrated at a three-fold higher axial resolution (< 5 mu m), using a portable, broadband, Cr4+:Forsterite laser as the optical light source. Images acquired from the esophagus and colon on animal model display tissue microstructures and architectural details at ultrahigh resolution, and the features observed in the OCT images arc well-matched with histology. The clinical feasibility study is conducted through delivering OCT imaging catheter using the standard endoscope. OCT images of normal esophagus and Barrett's esophagus are demonstrated with distinct features.