A number of diagnostic modalities exist for investigation of structural abnormalities of the esophagus. Which of the following statement(s) is/are true concerning the use of these investigative studies?

b.Barrett’s esophagus is suggested when the squamo-columnar junction is more than 2 cm above the gastroesophageal junction on endoscopic examination

c.There are three areas of esophageal narrowing which can be noted on both barium esophogram and endoscopy

d.The CT appearance of the esophagus is normally a flattened, hollow structure with a thin wall

Endoscopy is generally the first investigation in patients with foregut symptoms. The exception is when the patient’s chief complaint is dysphagia, when a “road map” should first be obtained by a barium swallow. The locations of the esophageal landmarks are measured endoscopically from the incisor teeth. Three landmarks are measured in the region of the cardia: the level of the crura, the level of the anatomic gastroesophageal junction, and the level of the squamo-columnar junction (Z line). A hiatal hernia is present when the gastroesophageal junction is more than 2 cm above the crura. Barrett’s esophagus is suggested when the squamo-columnar junction is more than 2 cm above the gastroesophageal junction but may be diagnosed if any specialized epithelium is identified above the gastroesophageal junction histologically, regardless of measured length of the columnar segment. Three areas of esophageal narrowing are frequently noted on both barium esophogram and endoscopy. The first narrowing is at the site of the cricopharyngeus muscle. The left mainstem bronchus and aortic arch caused narrowing of the middle third of the esophagus. The most distal narrowing of the esophagus is at the diaphragmatic hiatus and is caused by the lower esophageal sphincter mechanism. These normal points of narrowing tend to retard swallowed foreign objects. Also, corrosive liquid ingestion results in prominent mucosal injury at these sites as the liquid is slowed at passage. CT scan of the esophagus is important in delineating the relationship of esophageal lesions to adjacent structures, especially the trachea, left main bronchus and aorta. The esophagus normally appears as a flattened hollow structure with a thin wall. A more circular cross-sectional appearance with a fluid level is evidence of distal obstruction.