Imaging description

Intramural hematoma (IMH) is characterized by hemorrhage into the media of the aortic wall. It may be spontaneous or secondary to penetrating atheromatous ulcer or trauma. In the absence of trauma, it is included, along with penetrating atheromatous ulcer and dissection, under the clinical term “acute aortic syndrome.” IMH is most easily identified on noncontrast CT (Figure 44.1). The typical finding of high-attenuation crescentic or circumferential wall thickening may be masked by contrast material. By definition, communication between the hematoma and the true aortic lumen is absent. The Stanford classification for aortic dissection may also be applied to IMHs: Stanford A IMHs involve the ascending aorta while Stanford B involve only the descending aorta [1–5].

Importance

IMH has an unpredictable clinical course. IMH may resolve without sequelae, but may also progress to aortic dissection, develop ulcer-like projections (Figure 44.2), or rupture [1, 6].