Carotid and vertebral artery blood flow in left- and right-handed healthy subjects measured with MR velocity mapping.

The goal of the study was to establish normal carotid artery flow rates in left-handed and right-handed individuals as a standard against which patients with carotid artery disease could be compared. Antegrade and retrograde flow were measured in the ascending aorta, in the right and left common, internal, and external carotid arteries, and in the vertebral arteries of 12 healthy subjects. Five subjects were right-handed, five left-handed, and two ambidextrous. Measured flow rates were as follows: common carotid arteries, 360-557 mL/min (mean [+/- standard deviation], 465 mL/min +/- 52); internal carotid arteries, 132-367 mL/min (mean, 265 mL/min +/- 60); external carotid arteries, 113-309 mL/min (mean, 186 mL/min +/- 51); vertebral arteries from 133-308 mL/min (mean, 244 mL/min +/- 43); and cerebral circulation, 546-931 mL/min (mean, 774 mL/min +/- 134). All right-handed subjects had higher flow rates in the left internal carotid artery than in the right, and all left-handed subjects had higher flow rates in the right internal carotid artery (P = .007). There were no significant differences in left and right common carotid artery flow rates between left- and right-handed subjects. The standard deviation of a single measurement was 5%. The flow rates were similar to those obtained previously with other techniques and could be used as a normal standard.