Retropharyngeal pseudothickening is a mimic of retropharyngeal soft tissue thickening caused by neck flexion (which may also exacerbate airway obstruction), swallowing, or expiration.
It is important to consider when evaluating lateral cervical radiographs and sagittal cross-sectional imaging for airway obstruction, particularly in children 1,2.
Differential diagnosis
Pathologic causes of retropharyngeal or prevertebral soft tissue swelling should be considered, including:
retropharyngeal edema
retropharyngeal effusion secondary to acute calcific prevertebral tendinitis
retropharyngeal mass e.g. hemangioma, tumor