Hemodynamic MR evaluation of carotid artery flow in patients with extracranial occlusive vascular disease

In a series of patients undergoing carotid angiography for cerebral vascular symptoms, MR hemodynamic evaluations in the ipsilateral and contralateral arteries were compared. Turbulence artifacts from the stenosis were avoided by use of flow measurements obtained in the high cervical region. Two MR flow techniques have been compared in each patient: directly velocity encoding and bolus displacement using biplanar encoding. Both provide multiple flow velocities within the cardiac cycle. With stenosis greater than 75%, mean flow velocity was decreased in comparison with the contralateral vessel. The ipsilateral temporal velocity profile also had an abnormal configuration. Low OPG pressure correlated with decreased carotid a velocity. After endarterectomy, velocity profiles become symmetric