New imaging techniques at colonoscopy: tissue spectroscopy and narrow band imaging.

Although colonoscopy has undergone impressive development in recent decades, there remains a need for better endoscopic visualization in specific circumstances (eg, dysplasia screening in ulcerative colitis and detection of flat colorectal lesions). Many techniques are under investigation; this article discusses different forms of spectroscopy and narrow band imaging. Ideal colonoscopy should have high diagnostic accuracy and the ability to screen large mucosal areas. The most successful clinical method probably will be a combination of techniques, providing wide-area surveillance (such as fluorescence endoscopy or immunoscopy) and point detection methods, such as narrow band imaging or confocal microendoscopy, that can be used to identify the lesion further.