Background:The detection of the mucosal morphology(ie,mucosal and vascular patterns) in Barrett’s esophagus(BE) by magnifying(chromo) endoscopy may improve the distinction of high-grade intraepithelial neoplasia(HGIN) from nondysplastic specialized intestinal metaplasia(SIM) .Narrow band imaging(NBI) is a new technique that uses optical filters to enhance the mucosal contrast without the need for chromoendoscopy.Objective:To use NBI for the characterization and the classification of the mucosal morphology in nondysplastic BE and in BE with HGIN.Design:Descriptive study.Setting:Single-center study in a tertiary referral center for the diagnosis and treatment of patients with BE.Patients:We used NBI with magnifying endoscopy to image and biopsy randomly selected areas in 63 patients with BE.A systematic image and a biopsy specimen evaluation process was followed,including unblinded assessment of an exploratory set of images and biopsy specimens,and blinded evaluation of learning and validation sets.Main Outcome Measurements:The relationship between the mucosal morphology and the presence of SIM and HGIN.Results:SIM was characterized by either villous/gyrus-forming patterns(80%) ,which were mostly regular and had regular vascular patterns,or a flat mucosa with regular normal-appearing long branching vessels(20%) .HGIN was characterized by 3 abnormalities:irregular/disrupted mucosal patterns,irregular vascular patterns,and abnormal blood vessels.All areas with HGIN had at least 1 abnormality,and 85% had 2 or more abnormalities.The frequency of abnormalities showed a significant rise with increasing grades of dysplasia.The magnified NBI images had a sensitivity of 94%,a specificity of 76%,a positive predictive value of 64%,and a negative predictive value of 98% for HGIN.Limitations:No data on observer agreement.Conclusions:NBI with magnification reveals the mucosalmorphology characteristics of nondysplastic BE and HGIN,without the need for staining and has a relatively high diagnostic value for HGIN when used for targeted detailed examination of areas of interest. Background: The detection of the mucosal morphology (ie, mucosal and vascular patterns) in Barrett’s esophagus (BE) by magnifying (chromo) endoscopy may improve the distinction of high-grade intraepithelial neoplasia (HGIN) from nondysplastic specialized intestinal metaplasia (SIM). Narrow band imaging (NBI) is a new technique that uses optical filters to enhance the mucosal contrast without the need for chromoendoscopy. Objective: To use NBI for the characterization and the classification of the mucosal morphology in nondysplastic BE and in BE with HGIN. Design : Descriptive study. Setting: Single-center study in a tertiary referral center for the diagnosis and treatment of patients with BE. Patients: We used NBI with magnifying endoscopy to image and biologically selected areas in 63 patients with BE.A systematic image and a biopsy specimen evaluation process was followed, including unblinded assessment of an exploratory set of images and biopsy specimens, and blinded evaluation of learning and vali dation sets. Main Outcome Measurements: The relationship between the mucosal morphology and the presence of SIM and HGIN. Results: SIM was characterized by either villous / gyrus-forming patterns (80%), which were mostly regular and had regular vascular patterns, or A flat mucosa with regular normal-appearing long branching vessels (20%). HGIN was characterized by 3 abnormalities: irregular / disrupted mucosal patterns, irregular vascular patterns, and abnormal blood vessels. All areas with HGIN had at least 1 abnormality, and 85 % had 2 or more abnormalities. The frequency of abnormalities showed a significant rise with increasing grades of dysplasia. The magnified NBI images had a sensitivity of 94%, a specificity of 76%, a positive predictive value of 64%, and a negative predictive value of 98% for HGIN.Limitations: No data on observer agreement. Conclusions: NBI with magnification reveals the mucosalmorphology characteristics of nondysplastic BE and HGIN, without the need for staining and has a relatively high diagnostic value for HGIN when used for targeted detailed examination of areas of interest.