中文摘要：

目的探讨椎动脉起源异常和椎动脉发育不良（VAH）的发生率以及他们之间的关系,为影像诊断及临床手术提供资料和参考。方法回顾性分析2 370例患者的胸部增强MSCT影像资料,对原始图像进行技术重组,重点观察分析椎动脉起源及椎动脉V1段直径变化特点。逐例测量椎动脉V1段的内径。将椎动脉全程均匀性纤细,V1段内径〈2.5 mm定义为VAH。结果2 370例患者中左椎动脉起源异常131例（5.5%）,均发自主动脉弓。其中发自左颈总动脉和左锁骨下动脉之间主动脉弓126例（5.3%）,发自左锁骨下动脉远端主动脉弓5例（0.2%）。右椎动脉起源于右颈总动脉4例（0.16%）,均合并迷走右锁骨下动脉。根据椎动脉是否发自左颈总动脉与左锁骨下动脉之间主动脉弓,将检查者分为起源正常组与起源变异组。正常组（n=1 985）中,左侧VAH 71例,右侧VAH 144例。变异组（n=126）中左侧VAH共22例,右侧VAH共5例。两组差异有统计学意义（P=0.000）。结论左椎动脉直接起源于左颈总动脉和左锁骨下动脉之间的主动脉弓为最常见的椎动脉起源异常,其发生率女性高于男性。左椎动脉直接起源于主动脉弓与左椎动脉发育不良关系密切。

英文摘要：

Objective To determine the prevalence of anomalous origin of vertebral artery （VA） and vertebral artery hypoplasia （VAH）, and eval- uate the association between them, in order to provide information and reference for diagnostic imaging and clinical surgery. Methods A total of 2 370 patients who tmderwent thoracic enhanced computed tomography （CT） were included in this retrospective study. The original images were re- organized to observe and analyze the vertebral artery origin and diameter changes of V1 segment of the vertebral artery. The internal diameter of V1 segment of the vertebral artery was measured case by case. The uniformity and tenuity of the entire vertebral artery whose V1 segment had the internal diameter of less than 2.5 mm was defined as VAH. Results Totally 131 （ 5.5% ） in 2 370 cases of patients had anomalous origin of the left vertebral arteries which were all originated from the bottom of the aortic arch. Among these cases, 126 cases （5.3%） had vertebral artery originated directly from the aortic arch between the left common carotid artery and the left subclavian artery, and 5 cases （0.2%） originated from the aortic arch at distal end of left subclavian artery. There were 4 cases （0.16%） of the right vertebral artery originated from the right common carotid artery, which were merged with aberrant right subclavian artery. According to whether the vertebral artery was from the bottom of the aortic arch between the left common carotid artery and the left subclavian artery, the subjects were divided into the normal group and the variation group. There were 71 cases of left VAH and 144 cases of right VAH in the normal group （n = 1 985）, 22 cases of left VAH and 5 cases of right VAH in the variation group. Two groups were significantly different （ P= 0.000）. Conclusion The most common anomalous origin of vertebral artery is the left vertebral artery originated directly from the aortic arch between the left common carotid artery and the left subclavian artery. The