Trial Information

A Randomized Comparison Between White Light Endoscopy (WLE) and Bright Narrow Band Imaging (B-NBI) in the Diagnosis of Colonic Adenomas in Asymptomatic Subjects Undergoing Screening Colonoscopy

Removal of colorectal adenomas prevents occurrence of cancers [1]. It is recognized that
colonoscopy can miss colorectal adenomas and early cancers [2]. There is a need to further
improve performance of colonoscopy. The use of chromo-endoscopy has been shown to improve
detection of flat adenomas [3]. Narrow band imaging was introduced in year 2006. It is
similar to chromo-endoscopy in that it provides more mucosal details. This enables
endoscopists to accurately describe the pit pattern of adenomas. NBI has been used as a
substitute to chromo-endoscopy. In pooled analysis, NBI is comparable to chromo-endoscopy in
their sensitivity and specificity in the diagnosis of malignant colorectal adenomas [4].
Unfortunately, the use of NBI has not been shown to conclusively improve rate of colorectal
adenoma detection. Two of 3 randomized trials that compared WLE to NBI showed a higher
adenoma detection rate with the use of NBI [5, 6]. In a study by Rex et al., the rate was
however similar with either modality. In a pooled analysis, NBI was only marginally better
than WLE [4].

The effective use of NBI depends on the quality of bowel preparation and the experience of
endoscopist. In the presence of fecal matters, NBI tends to be dark and detection of small
adenomas becomes difficult. The prototype bright NBI coupled with high definition resolution
is likely to overcome this drawback of original NBI.