For the secondary outcome of detection of HGD will be based on number of biopsies harboring HGD. If we assume that NBI/AFI can detect areas of HGD (within the BE segment) in 90% of the biopsies from irregular/distorted patterns compared to 60% by standard endoscopy, we would need to study 59 areas/biopsies of HGD in order to detect a significant difference between the two with 80% power and a type 1 error rate of 5% using McNemar's test for paired dichotomous responses. If we enroll at least 10-12 patients with HGD with an average BE length of 5 cms, we will be able to evaluate > 60 areas of HGD with each procedure. Each site will have to enroll approximately 30-35 BE patients (including 5-6 with HGD) each year.