Optical coherence tomography in detection of dysplasia and cancer of the gastrointestinal tract and bilio-pancreatic ductal system

Figure 3 Magnification of an OCT image from the normal common bile duct wall. From the surface of the duct, up to a depth of 1 mm, the following layers are recognizable: the single layer of epithelial cells, approximately 0.04-0.06 mm thick, visible as a superficial, hypo-reflective band (a); the connective-muscular layer surrounding the epithelium, visible as a hyper-reflective layer approximately 0.34-0.48 mm thick (b); the connective layer visible as a hypo-reflective layer with longitudinal relatively hyper-reflective strips (smooth muscle fibers) (c).