Autofluorescence imaging and narrow-band imaging for the detection of early neoplasia in patients with Barrett's esophagus

High-resolution endoscopy (HRE), magnifying endoscopy, autofluorescence endoscopy, and narrow-band imaging (NBI) are promising techniques that could improve the detection of early neoplasia and the efficacy of endoscopic surveillance in patients with Barrett's esophagus. HRE improves the detection of lesions by white light, and video autofluorescence imaging (AFI) may have additional value in terms of sensitivity. The strengths of AFI are its high sensitivity and a high negative predictive value, while potential limitations are its moderate specificity and positive predictive value. NBI enhances the mucosal and vascular patterns (i.e. the mucosal morphology) without the need for chromoendoscopy. The mucosal morphology features may be used to distinguish early neoplasia from nondysplastic Barrett's esophagus. Magnification is required for optimal use of NBI, which is a limitation of this technique. NBI with magnifying endoscopy could, however, be used for targeted inspection of lesions detected first by HRE or AFI. This approach has been shown to reduce the false-positive rate associated with AFI while maintaining its high sensitivity. To date, AFI and NBI have been used separately in two different prototypes, but a prototype endoscope that incorporates all of these techniques has recently become available. It is expected that future refinement of the autofluorescence and narrow-band modules may further increase their diagnostic value and ultimately improve the effectiveness of surveillance of Barrett's esophagus.