Mild thickening of the aortic wall: subtle intramural hematoma?

Recently published criteria for the diagnosis of intramural hematoma (IMH) of the ascending aorta by transesophageal echocardiogram (TEE) include the presence of a crescent-shaped thickening of the aortic wall of more than 7 mm with an echolucent space. We report a patient whose clinical presentation suggested aortic dissection but whose TEE failed to meet the conventional criteria for such a diagnosis. TEE showed a uniform intimal thickening suspicious of IMH but less than 7 mm in thickness and with no echofree space. One week later, the patient developed frank aortic dissection.

IMH can present with a subtle echo appearance. The diagnosis should not be totally discounted in the absence of a 7-mm crescentic wall thickness and an echofree space if the clinical presentation is suggestive of dissection.