NAVLE® Question of the day

MO TU WED TH FR
June 28, 2022
NAVLE

A long eared owl with a history of wing amputation is presented with anorexia, lethargy, and ataxia. Radiograph are shown below. 

The top image is a plain lateral radiograph. The bottom lateral radiograph was obtained after oral administration of 7 mL 50% barium suspension. 

Which one of the following structures has pathology?