title: Another look at the "ring-around-the-artery" in pneumomediastinum.
abstract: Gas surrounding the right pulmonary artery has been observed in three patients, including two in whom it was demonstrated around the intrapericardial right pulmonary artery on frontal films. This would provide a pathway for occasional development of spontaneous pneumopericardium.
mesh_terms: D000328:Adult; D002675:Child, Preschool; D006801:Humans; D008297:Male; D008478:Mediastinal Emphysema / Q000000981:diagnostic imaging* / Q000473:pathology; D011651:Pulmonary Artery; D013902:Radiography, Thoracic