Barrett esophagus is a well-recognized entity in which there is progressive columnar metaplasia of the lower esophagus due to longstanding gastroesophageal reflux and reflux esophagitis [1]. This condition is important because it is associated with an increased risk of developing esophageal adenocarcinoma by a well-established sequence from dysplasia to carcinoma [2]. During the past decade, however, an explosion of new data has dramatically affected our understanding of Barrett esophagus. Not only have revised histopathologic criteria been developed for this condition, but it is currently believed that patients with Barrett esophagus should be classified as having “short-segment” or “long-segment” disease based on the extent of columnar metaplasia in the distal esophagus. This distinction has important implications for the risk of developing esophageal adenocarcinoma and subsequent need for endoscopic surveillance. The purpose of this article is to present these new concepts about Barrett esophagus and provide radiologists with a more current framework for diagnosing this condition.