Symptomatic carotid artery occlusion: Flow territories of major brain-feeding arteries

Purpose: To prospectively investigate the extent of flow territories of the contralateral internal carotid artery (ICA) and vertebrobasilar arteries in patients with symptomatic ICA occlusion. Materials and Methods: Ethics committee approval and informed consent were obtained. Flow territory mapping of the ICA contralateral to the occluded ICA and mapping of the vertebrobasilar arteries were performed by using selective arterial spin-labeling magnetic resonance imaging in 23 functionally independent patients (22 men, one woman; mean age, 58 years +/- 8 [standard deviation]) with symptomatic ICA occlusion. The control group consisted of 68 subjects (57 men, 11 women; mean age, 59 years +/- 9) without hemodynamically significant ICA obstruction. Voxel-based chi(2) testing with Bonferroni correction was performed to analyze significant differences in the extent of the flow territories. Results: Flow territory maps in patients with symptomatic ICA occlusion showed significant differences in the flow territories of the contralateral ICA and vertebrobasilar arteries compared with those in control subjects (P < .05). Conclusion: In functionally independent patients with symptomatic ICA occlusion, the middle cerebral artery flow territory ipsilateral to the occluded ICA is mainly supplied by the vertebrobasilar arteries, whereas the anterior cerebral artery flow territory on the occluded side is mainly supplied by the contralateral ICA.