Retrocardiac Lucency in Neonates: Air Trapped in the Pulmonary Ligament.

Air trapped in neonates' pulmonary ligament is often the consequence of positive pressure ventilation and its typical radiographic appearance must be recognized in order to prevent the use of aggravating factors. Air trapped in neonates' pulmonary ligament is often the consequence of positive pressure ventilation; its typical waterdrop appearance must be recognized on radiographs to prevent unnecessary additional measures.