False positive computed tomography findings in aortic dissection

Dissection is the commonest acute catastrophe involving the aorta. Computed tomography (CT) is increasingly used in evaluating patients with suspected aortic dissection. Occasionally normal anatomic structures may be misconstrued as pathologic due of lack of familiarity with anatomical variations. In scanning two patients with suspected dissection, we encountered pitfalls that led to an erroneous diagnosis of dissection. The subsequent clinical course and evaluation confirmed that the CT findings were artefactual. This report illustrates these potential errors and discusses the mechanisms.