Near-focus (NF) narrow-band imaging (NBI) is an image-magnifying technology which enables optical magnification of up to 65x in near focus (NF) compared with 52x in normal standard focus (SF) with the simple push of a button of the endoscope to be interchangeable between NF and SF. There were few studies comparing diagnostic accuracy between NF and SF in the diagnosis of colorectal polyps. So, our aim of the current study is to compare accuracy of NF NBI compared with SF NBI in the optical diagnosis of neoplastic and non-neoplastic polyp and the accuracy of NF NBI versus SF NBI in distinguishing serrated adenoma from hyperplastic polyp in sessile lesions using histologic evaluation as the gold standard.
Optical diagnosis of colorectal polyps is a promising tool to avoid risks of unnecessary polypectomies and to save costs of tissue pathology. NICE (NBI International Colorectal Endoscopic) and WASP (Workgroup on Serrated Polyps and Polyposis) classification were developed for diagnosis of adenomatous and sessile serrated polyps, respectively.