The impact of narrow band imaging in screening colonoscopy: a randomized controlled trial

Narrow band imaging (NBI) is an imaging technique that allows a better definition of capillary pattern and improves the contrast between adenomas and the surrounding mucosa. Conflicting data exist on the ability of NBI to improve detection of colonic neoplasm; the impact of NBI is being tested in several screening scenarios. We evaluated whether the routine use of NBI, compared with white light (WL), during the withdrawal phase of screening colonoscopy improved adenoma detection.

This randomized controlled study included consecutive 50- to 69-year-old patients with positive immunologic fecal occult blood tests. They were randomly assigned to groups that were examined with WL (n = 108) or NBI (n = 103) during the withdrawal phase of their colonoscopies. The primary end point was the adenoma detection rate. The prevalence of non-polypoid and the total number of adenomas were also evaluated.

The number of total and mean per-patient adenomas were 201 (1.95 +/- 2.3) and 198 (1.83 +/- 2.1) in the NBI and WL groups, respectively (P = .69). The adenoma detection rates were 57.3% for patients examined by NBI and 58.3% for those examined by WL (P = .88). A total of 41 non-polypoid adenomas were identified (26 in the NBI and 15 in the WL groups, P = .16). The flat adenoma detection rates were 21.4% and 9.3% in the NBI and WL groups, respectively (P = .019).

The routine use of NBI in screening colonoscopy did not increase the adenoma detection rate. NBI seems to improve the detection of flat adenomas, although additional studies are necessary.