Atypical patterns in the CT diagnosis of aortic dissection

Eight cases of aortic dissection with atypical CT appearances are described. Seven were clinical diagnoses, one was confirmed at operation. The findings were those of intramural haematoma, often crescentic and not necessarily compressing the aortic lumen. Evidence is presented to show that some intramural haematomas may subsequently develop ulceration, resulting in the appearances described in penetrating atheromatous ulcer of the aorta.