Imaging of the Esophagus

Abstract

The esophagus is a tubular structure measuring approximately 25 cm in length, connecting the pharynx and the stomach. Most of the esophagus lies in the thorax, with small cervical and intra-abdominal segments. The longest thoracic segment lies posterior to the trachea in the midline, until the tracheal bifurcation, after which it courses slightly left of the midline to cross the diaphragm via the diaphragmatic hiatus and forms the gastroesophageal junction. The abdominal esophagus lies posterior to the left lobe of the liver. The esophagus is therefore composed of a short cervical segment, a long thoracic segment, and a short abdominal segment [1, 2]. The esophageal wall consists of four layers: mucosa, submucosa, muscular layer, and external fibrous layer [3]. The upper third of the esophagus consists of striated muscles, gradually transitioning into completely unstriated muscles in the distal third. Columnar epithelium lines the distal third and gastroesophageal junction, with squamous epithelium lining the rest of the esophagus.