Magnetic resonance demonstration of vertebral artery dissection. Report of two cases.

Vertebral artery dissection may be spontaneous or related to some traumatic event. Diagnosis has usually been made by angiography, an invasive procedure with certain well-known risks. The authors describe the magnetic resonance (MR) appearance (both on conventional spin-echo and on gradient refocused "flow" sequences) in two patients with vertebral artery dissection confirmed by angiography. It is proposed that the less invasive MR imaging might be the imaging modality of choice for initial evaluation of suspected vertebral artery dissection.