Advanced diagnostic imaging in colonic disease

Abstract

Advanced colonic imaging refers to the use of techniques such as high definition white light, standard white light with chromoendoscopy, virtual chromoendoscopy (narrow band imaging), autofluorescence imaging and endomicroscopy to evaluate the colonic mucosa. The main aims of both advanced colonic imaging are to enhance the mucosal detail and to allow a detailed view of the submucosal capillary pattern, thus potentially improving the detection of more pathological lesions. The mucosal surface of neoplastic and non-neoplastic growths develops into specific mucosal convolutions, also called "pit pattern". Neoplasia also leads to angiogenesis with its resulting vessel proliferation and disarray. Because both the pit pattern and the submucosal capillary network are disarranged in the presence of neoplasia it is compelling to hypothesize that advanced imaging methods will allow the endoscopist a better interrogation of lesions with a resulting increase in diagnostic sensitivity and specificity (i.e. differentiation of lesions). However, the current literature dealing with advanced endoscopic imaging of the colon is fraught with many controversial findings, with few experts vehemently supporting the use of most of these methods in routine clinical practice, whereas most practicing endoscopists still effuse to accept that this methods aid in the clinical routine. This review describes the concept of advanced endoscopic imaging. We conclude that advanced endoscopic imaging of the colon holds many promises, but with the exception of high definition white light endoscopy, at the present stage, there is no solid evidence to support the implementation of most advanced endoscopic methods in routine clinical practice.