Axial CT with contrast of the chest at the level of the aortic arch (above left) shows a large amount of fluid in the superior mediastinum while subsequent lower slices (above right and below left) show an intimal flap in the descending aorta. Sagittal CT (below right) shows a pseudoaneurysmal dilation of the aorta beginning at the aortic isthmus.
Pediatric Imaging 