Figure 11a. Aortic stenosis in a 42-year-old man who had undergone surgical repair of aortic coarctation in childhood and whose symptoms at the time of scanning included hypertension and weak femoral pulses. (a, b) Contrast-enhanced axial CT images of the thoracic aorta show a calcified prosthesis (large arrow) in the proximal descending thoracic aorta. The prosthesis has become detached from the left wall, producing partial aortic thrombosis and stenosis (small arrow in b). Note the enlarged internal mammary arteries (arrowheads in a). (c) Sagittal oblique reformatted image of the thoracic aorta shows movement of the aortic stent-graft (large arrow) and secondary aortic stenosis (small arrow).