Aortic intramural hematoma, which is one of the acute aortic syndromes, is due to bleeding within the aortic wall. It may be caused by rupture of the vasa vasorum within the media or due to hemorrhage from a penetrating atherosclerotic ulcer.

The CT scan shows a type A aortic intramural hematoma. Most intramural hematomas (60-70%) involve the descending aorta (type B) and has better prognosis than those involving the ascending aorta (type A). The lesion may resolve, remain stable or evolve into a full-blown aortic dissection or aneurysm.