Here is the Endoscopic Optical Coherence Tomography (OCT) for Pancreatic and Biliary Applications Optical Coherence Tomography (OCT) or Volumetric Laser Endomicroscopy (VLE) transmits infrared light into tissue, measures back-reflected light from the tissue microstructure to see beneath the surface and providing physicians with comprehensive volumetric high resolution images of the esophagus and bile duct in real-time. Credit: NvisionVLE Imaging System | SurgMedia