ABSTRACT
The oesophagus is a muscular tube connecting the pharynx to the stomach. It starts at the level of the cricoid cartilage and ends at the oesophagogastric junction. In the neck, it descends behind the trachea and anteriorly to the vertebral column following its curvature into the thorax. There are multiple relative constrictions along the oesophagus. First is the upper oesophageal sphincter; second is where the arch of the aorta/left main bronchus crosses the oesophagus; and third is the lower oesophageal sphincter. As a posterior mediastinal structure, the oesophagus is normally obscured on plain radiographs by other structures such as the spine, major vessels, airway and heart. Endoscopy is an essential tool with both diagnostic and therapeutic roles. Endoscopic ultrasonography relies on a high-frequency transducer to provide highly detailed images of the layers of the oesophageal wall and mediastinal structures close to the oesophagus.
