Clinical Evaluation of Narrow Band Imaging Colonoscope

This is a clinical study to evaluate whether the use of a new type of colonoscope may improve the detection of colon polyps. Though colonoscopy is currently the best test for colon cancer screening, it remains imperfect. Research has found that about 25% of polyps may actually be missed during colonoscopy using standard full spectrum white light imaging. Advances in colonoscopic technology hold the potential to decrease the miss rate of colorectal neoplasms. A new colonoscope uses narrow band imaging, whereby the colon is illuminated using only a subset of the white light spectrum, 415nanometers (blue) and 540 nanometers (green) rather than the standard full spectrum white light (red, green and blue). Initial studies by other groups suggest that these narrow band images highlight small blood vessels of colon polyps. As such, we hypothesized that the use of NBI would improve the identification of neoplasms through the color differentiation of precancerous or cancerous polyp (appearing brown) from normal colon mucosal lining (appearing green), and potentially lead to a reduction in polyp miss rate. We aimed to study the polyp miss rate, and compare narrow band imaging to white light examination.

Inclusion criteria

• referred for elective outpatient colonoscopy

Exclusion criteria

• known inflammatory bowel disease
• personal or family history of polyposis syndrome
• referral for resection of a known lesion