Magnetic resonance angiography of an aortic dissection.

A 51-year-old man with hypertension had previously been admitted to our cardiothoracic unit with a type A aortic dissection (Stanford classification) and had undergone emergency surgery with partial replacement of the ascending aorta. Routine follow-up magnetic resonance angiography (MRA) 19 months after the operation revealed an aneurysm at the incision site in the ascending aorta and extension of the dissection into the descending aorta. MRA was performed with 2 sequential breath-hold 3D contrast-enhanced scans, each lasting 25 seconds.1,2 The resolution of the reconstructed images was 2.032.231.5 mm. For postprocessing, the scans were sent to an offline workstation (EasyVision, Philips Medical Systems), where 3D shaded surface renderings were created. Surface renderings of the first scan allowed excellent evaluation of the ascending and descending aorta as well as the aortic arch. In the ascending aorta, a patch-like aneurysm '7319329 mm was seen (Figures 1 and 2). The descending aorta shows tapering of the lumen from just proximal to the diaphragmatic hiatus all the way into the iliac arteries. Images of the second scan clearly show the filling of a huge false lumen from the iliac arteries all the way up to the diaphragmatic hiatus (Figures 3 and 4). The total length of the dissection is .25 cm. On image 4, it can be appreciated that the left kidney is dependent on the false lumen for its blood supply. Examination of the source images showed that the only patent connection between the true and false lumina was in the left iliac artery (Figure 4). The patient remains asymptomatic at this writing and will be followed up carefully for progression of the disease.