Narrow band imaging (NBI) is a new novel technique in which the resolution of endoscopes increase because the spectral bandwidth of filtered light is narrowed. Blue light with shorter wavelength and higher penetration is used. It enhances the contrast of the mucus membrane without staining. The contrast and acuity of mucosa and submucosal capillaries are enhanced, so the accuracy of endoscopic diagnosis is improved
1. Increased Sensitivity in Non erosive esophageal gastritis (NERD)
2. Dysplasia in Barrett's esophagus
3. Early esophageal cancers - NBI can clearly show the pit pattern and blood capillary form of early esophageal cancer and precancerous lesions.
No need to spray dyes like methylene blue
1. Gastric Metaplasia
2. Detection of early gastric cancer Accuracy is 90.4%
3. H. pylori associated chronic gastritis
1.Invasion depth of early colorectal cancers and evaluating free margins after endoscopic resection
2. Detect dysplasia in long standing inflamatory bowel disease
Future research should focus on establishing a reliable NBI nomenclature for capillary patterns, defining learning curve and interobserver variation, and validating the effectiveness of NBI in routine colonoscopy.
Statement 1. NBI contrasts vascular architecture and surface structure of the superficial mucosa
Statement 2. Image processor settings, that is, processing system, contrast enhancement and color tone, affect diagnostic accuracy of NBI
Statement 3. Magnifying (zoom) endoscopy is essential for NBI observation