Trial Information

A Randomised 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 chromoendoscopy has been shown to improve
detection of flat adenomas [3]. Narrow band imaging was introduced in year 2006. It is
similar to chromoendoscopy 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 chromoendoscopy.

In pooled analysis, NBI is comparable to chromoendoscopy 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 [7].

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.