Figure 16a. Figures 15, 16. (15) Pseudoaneurysm after surgery for type A dissection in a 28-year-old man with Marfan syndrome. The surgery involved replacement of the aortic valve and placement of a Dacron graft in the aortic root. (a) Enhanced CT scan shows a pseudoaneurysm of the aortic root (arrows). Note the aortic motion artifacts (arrowheads). (b) SSD image shows the pseudoaneurysm of the aortic root (arrow). (16) Aneurysm after surgery for type A dissection 9 years earlier. The surgery involved replacement of the aortic valve and angioplasty of the intimal tear with a patch graft. (a) Enhanced CT scan shows an aneurysm of the ascending aorta with a persistent intimal flap (arrow). (b) SSD image shows the aneurysm of the ascending aorta with extension to the aortic arch.