Willis环解剖变异的64层容积CT数字减影血管造影研究

Anatomic variations of Willis circle by 64-slice volume CT digital subtraction angiography

目的通过64层容积CT数字减影血管造影(volume CT digital subtraction angiography,VCTDSA)研究Willis环的正常解剖和变异。方法分析2006年2月至2008年9月在我院行头部或头颈部VCTDSA检查的174例患者资料,观测Willis环各组成动脉的发育情况、形态、大小,Willis环的完整性及Willis环穿支小血管的显示情况。结果①Willis环动脉发育不良各段均有发生,按发生率不同依次为L-PCoA(20.1%)、R-PCoA(16.1%)、R-ACA A1(13.8%)、R-PCA P1(9.2%)、ACoA(7.3%)、L-PCA P1(6.3%)及L-ACA A1(3.4%),动脉缺如以R-PCoA(54.6%)、L-PCoA(52.3%)、ACoA(15.8%)为高。②174个Willis环中,后循环发育不良或缺如占55.8%,前后循环发育不良或缺如占29.8%,具有完整形态Willis环的仅占9.2%。③174个Willis环清楚显示穿支血管17支,平均直径0.82 mm。Heubner回返动脉26支,平均直径0.94 mm。结论VCTDSA对Willis环显示完整、清晰,多角度显示能发现Willis环的各种变异,并显示Willis环穿支小血管。

Objective To investigate the normal anatomy and variation of Willis circle by 64-slice volume CT digital subtraction angiography （VCTDSA）. Methods VCTDSA data of 174 patients with cephalocervical and cephalic scanning in our hospital from February 2006 to September 2008 were analyzed. Developmental condition, shape, size, integrity, and perforating branches of Willis circle were observed. Results （ 1 ） Hypoplasia was displayed in any component vessels of Willis circle. Incidence rate of hypoplasia was 20.1% in left posterior communicating artery, 16. 1% in right posterior communicating artery, 13.8% in right anterior cerebral artery A1, 9.2% in right posterior cerebral artery P1,7.3% in anterior communicating artery, 6.3% in left posterior cerebral artery P1, and 3.4% in left anterior cerebral artery A1. Congenital arterial absence occurred more frequently in right posterior communicating artery （54.6%）, left posterior communicating artery （52.3%）, and anterior communicating artery （ 15.8% ）. （2） Hypoplasia or congenital absence of posterior circulation and anterior-posterior circulation occurred with a rate of 55.8% and 29.8% respectively. Integrity of Willis circle was only 9.2%. There were 17 perforating branches and 26 heubner inversion arteries observed in 174 Willis circle, with an average diameter of 0.82 mm and 0. 94 mm respectively. Conclusion VCTDSA can display Willis circle completely and clearly. Using three-dimensional rotation may detect all kinds of varia tion and perforating branches of Willis circle.