Esophageal Motility and Mechanical Problems
Radiograph	Disease	Description
	Achalasia	A motility disorder may be caused by dysfunction of the lower esophageal sphincter (LES) leading to progressive esophageal dilation with dysphagia. Ganglion cells in the myenteric plexus may be reduced.
	Diverticula	Dysmotility may produce outpouchings in areas of muscular wall weakness. Pulsion diverticula are outpouchings that occur in upper esophagus (a Zenker's diverticulum below the cricopharyngeal muscle) and lower esophagus (an epiphrenic diverticulum above the diaphragm). A traction diverticulum in the midesophagus may result from mediastinal lymphadenitis.
	Rings and Webs	A functional stenosis of the lower esophagus just above the diaphragm may produce a ring-like lesion on radiography known as Schatzki's ring. Rarely seen is an upper esophageal web in association with iron deficiency anemia known as Plummer-Vinson syndrome. Obstruction with dysphagia result from these conditions.
	Hiatal Hernia	An increased size of the diaphragmatic hiatus can lead to a "sliding" hernia in which a section of upper gastric fundus extends through the opening. The very rare "paraesophageal" hernia occurs when a large portion of more distal fundus herniates upward, often with disruption of the blood supply and gastric wall ischemic injury.
	Paraesophageal Hernia	Rarely, all or most of the gastric fundus may herniate through the esophageal hiatus, trapping the stomach with disruption of the blood supply and gastric wall ischemic injury.

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