The purpose of this study is to determine if early Barrett's specialized intestinal metaplasia can be detected by measuring early increased blood supply of the esophageal tissue, with 4 Dimensional Elastic Light-Scattering Fingerprinting, (4D-ELF) technology in real time.

Inclusion Criteria:

• age 18 years or older,
• informed written consent,
• patient scheduled for previously planned upper endoscopy

Exclusion Criteria:

• liver disease;
• gastric antral vascular ectasia (GAVE);any known non-esophageal aerodigestive malignancy;
• severe cardiopulmonary disease precluding endoscopy; presence of conditions not allowing biopsy (e.g. coagulation disorder);
• known familial polyposis syndrome (FAP, HNPCC, Juvenile polyposis, etc.);
• known pregnancy or sexually active females of childbearing age who are not practicing an accepted form of birth control.

Control Population: Patients with no Barrett's metaplasia scheduled for upper endoscopy at Mayo Clinic Jacksonville.

Experimental Population: Patients with biopsy-proven Barrett's esophagus and previously scheduled for upper endoscopy at Mayo Clinic Jacksonville.