Fig. 1

SPM in patient-1: (A) Day 2: Spinnaker-sail sign observed. (B) Day 11: Near complete resolution. Yellow arrows: lateral borders of the fascia extending over the thymus and pericardium, which trap leaked air and cause outward bulging of the pericardium. White arrows: entrapped air behind this fascia. Blue arrows: leaked air surrounding the mediastinal structures. T: Thymus. H: Heart