Postcricoid region and cervical esophagus: normal appearance at CT and MR imaging.

PURPOSE: To establish the normal variations of the postcricoid portion of the hypopharynx, esophageal verge, and cervical esophagus, as seen on computed tomographic (CT) and magnetic resonance (MR) images.
MATERIALS AND METHODS: One hundred twenty-one CT and 92 MR images were reviewed. Diameter and wall thickness were measured at multiple levels. Depiction of the layers of the musculature and adjacent fat planes was evaluated. The frequency and size of the tracheoesophageal lymph nodes were noted.
RESULTS: An esophageal anteroposterior diameter greater than 16 mm and lateral diameter greater than 24 mm were considered abnormal. The average wall thickness was 4.8 mm laterally and 3.8 mm posteriorly. Demonstration of the intramural fat planes of the postcricoid region decreased from the upper to the lower region of the cricoid cartilage. The ability to separate the esophageal wall from the trachea was highest at the esophageal verge and declined markedly more distally. The tracheo-esophageal groove nodes were seen more often on the right (mean size [+/- SD], 4.5 mm +/- 2.2).
CONCLUSION: Knowledge of the normal appearance and variations of the post-cricoid region and cervical esophagus is essential in detecting abnormalities in these areas.