Fig. 14From: Thoracic abnormal air collections in patients in the intensive care unit: radiograph findings correlated with CTPneumomediastinum of a 43-year-old man with acute myelogenous leukemia. a Erect lateral radiograph shows the “ring around the artery” sign. b A sagittal CT image also shows a lucent ring (arrows) surrounding the right pulmonary artery (asterisk), a feature called the “ring around the artery” signBack to article page