Figure 15 - Cricopharyngeal bar with jet phenomenon.

There is a very prominent thumb-like indentation at the pharyngoesophageal junction (white arrow) representing a cricopharyngeal bar. A flow or "jet phenomenon" (black arrows) is seen below confirming luminal narrowing. (Source: Jones B, Kramer SS, Donner MW. Dynamic imaging of the pharynx. Gastrointest Radiol 1985;10:213–224, with permission from the authors.)