Novel imaging techniques and endoscopic therapies Significant effort has been expended on development of new GI techniques in order to provide a precise and even a "real time" endoscopic diagnosis. Chromoendoscopy is a technique that involves the application of agents to improve characterization of the mucosa resulting in selective uptake or enhancement of mucosal surface pattern (11). HRE units are equipped with charge-coupled devices with up to a million pixels that allow clear visualization of fine mucosal details which may facilitate the detection of early neoplastic lesions (9). NBI is a novel endoscopic technique that is based on the optical phenomenon that the depth of light penetration into tissues is dependent on the wavelength; the shorter the wavelength, the more superficial the penetration. Use of blue light with narrow band filters enables detailed imaging of the mucosal and vascular surface patterns within the BE segment with a high level of resolution and contrast without the need for chromoendoscopy. The main chromophore in esophageal tissues in the visible wavelength is hemoglobin, which has a maximum absorptive wavelength near 415 nm. This is within the wavelength for NBI and responsible for revealing the superficial vasculature (10).