To investigate the correlation of vertebral artery dominance(VAD) with incidence and laterality of posterior circulation infarct, and observe the correlation of VAD and basal artery(BA) curvature.

Total incidence of posterior circulation infarcts, incidence of separate territory infarcts in posterior circulation and incidence of BA curvature were compared between 68 VAD patients and 66 controls. VA dominance, laterality of BA curvature and separate territory infarcts, and their directional relationships were observed in VAD group.

The total incidence of posterior circulation infarcts in VAD group was significantly higher than that in controls(45.6%(31/68) vs 21.2%(14/66)，χ²=8.922，P=0.003). The incidences of posterior inferior cerebellar artery (PICA) territory infarct and BA territory infarct were both significantly higher than that in controls (11.8%(8/68) vs 0,χ²=8.250，P=0.004；20.6%(14/68) vs 7.6%(5/66)，χ²=4.660，P=0.031). No differences were found in superior cerebellar artery (SCA) and posterior cerebral artery (PCA) territory infarcts between two groups. 87.5%（7/8）PICA infarcts were on the opposite side of dominant VA . 42.9%(6/14)BA infarcts were on the side of dominant VA. The incidence of BA curvature was significantly higher than that in controls（50.0%(34/68) vs 9.1%(6/66)，χ² =26.768， P=0.000）. No differences were found in the incidences of posterior circulation infarcts between BA curvature patients and BA straight patients（52.9%(18/34) vs 38.2%(13/34), χ² =1.482，P=0.223）. 97.1%（33/34）patients had an opposite directional relationship between dominant VA and BA curvature in 37 BA curvature patients in VAD group.

The incidence of posterior circulation infarcts is higher in VAD patients, especially in PICA infarct and BA infarct patients. Most PICA infarcts occurred on the opposite side of dominant VA. The incidence of BA curvature is higher in VAD patients, and BA usually bends to the opposite side of dominant VA.

Vertebrobasilar insufficiency; Vertebral artery; Congenital adnormalities; Brain infarction; Basilar artery