颅内动脉变异的颅脑磁共振血管成像特征分析

MRA Features of Intracranial Arterial Variation

目的分析颅内动脉变异的脑动脉磁共振血管成像(MRA)特征。方法选择2013年2月至2015年2月于榆林市星元医院接受颅脑磁共振成像平扫及颅内MRA检查者408例,观察大脑前动脉、大脑中动脉、大脑后动脉、颈内动脉颅内段、椎-基底动脉变异的存在、数量及形态特征,并分析大脑前动脉变异与大脑后动脉变异间的关系。结果大脑前动脉变异发育不良42例,缺如34例。一侧后交通动脉显示167例,双侧后交通动脉显示82例。共显示完全胚胎型大脑后动脉22例,典型胚胎型大脑后动脉80例,双大脑后动脉20例。1例存在颈内动脉系统与椎-基底动脉系统变异型沟通,表现为左侧永存三叉动脉。2例存在大脑中动脉变异,分叉点距离大脑中动脉起点分别为8 mm和10 mm。42例单侧大脑前动脉A1段发育不良者中,同时伴有同侧后交通动脉增粗10例、同侧胚胎胚胎型大脑后动脉2例。34例单侧大脑前动脉A1段缺如者中,同时伴有同侧后交通动脉增粗18例、同侧胚胎胚胎型大脑后动脉12例。结论脑动脉变异具有一定的分布特征,其中大脑后动脉变异最多,脑动脉MRA可以对其进行清晰的显示。

Objective To analyze the magnetic resonance angiograghy （MRA） features of intracranial arterial variation. Methods A total of d08 patients undergoing MRI scan and MRA scan in Yulin Xingyuan Hospital from Feb. 2013 to Feb. 2015 were included in the study, to observe the number and the shape of the cerebral artery, middle cerebral artery, posterior cerebral artery, intracranial segment of internal carotid artery and vertebral basilar artery variation of the brain, and the relationship between the variation of the anterior cerebral artery and the posterior cerebral artery was analyzed. Results There were 42 cases of anterior cerebral artery dysplasia, 34 cases of anterior cerebral artery agenesis. There were 167 cases of unilateral posterior communicating artery, 82 cases of bilateral posterior communicating artery. There were 22 cases of total embryonic cerebral artery, 80 cases of typical embryonic cerebral artery in, 20 cases of double posterior cerebral artery. There was 1 case of internal carotid artery system and the variation of the vertebral hasilar artery system,left persistent trigeminal artery ;2 cases with middle cerebral artery variation, and the distance from bifurcation point to the middle cerebral artery was 8 mm and 10 mm respectively. In 42 cases of unilateral anterior cerebral artery A1 segment dysplasia,there were 10 cases complicated with the posterior communicating artery thickening,2 cases of ipsilateral embryonic type posterior cerebral artery. In 34 cases of unilateral anterior cerebral artery A1 segment absence,there were 18 cases of artery with pos-terior communicating artery thickening, 12 cases of ipsilateral posterior cerebral artery. Conclusion Cerebral arterial variation has a certain distributive feature, the incidence of posterior cerebral artery variation is the highest, which can be clearly reflected by MRA.