Magnetic resonance angiography of cervicocranial dissection.

BACKGROUND: A retrospective study of five patients with the clinical or magnetic resonance-based diagnosis of carotid dissection was done. Clinical data, imaging studies, treatment, and outcome were reviewed. The potential applicability of three-dimensional time-of-flight magnetic resonance angiography in these settings was evaluated. SUMMARY OF REPORT: This modality reliably showed vascular abnormalities and focal, segmental, or aneurysmal dilatation when correlated with conventional angiograms in three patients. Turbulence and magnetic susceptibility at the acute turn of the carotid in the petrous canal led to a false-positive diagnosis on magnetic resonance angiography in one patient (in whom subtle fibromuscular hyperplasia was found with conventional angiography but missed with magnetic resonance angiography). CONCLUSIONS: When combined with appropriate clinical signs, magnetic resonance imaging and magnetic resonance angiography can reliably establish the diagnosis of carotid dissection. Pitfalls of magnetic resonance angiography are discussed.