Air collection in the retropharyngeal soft tissues observed in lateral expiratory films of the neck in 9 infants.

This is the report of 9 infants in whom a lateral roentgenogram of the neck exposed in expiration showed an increase in the thickness of the retropharyngeal soft tissues with a small collection of air within these soft tissues simulating a retropharyngeal abscess. Both findings disappeared in inspiration consistent with normal variants.