Objective to observe the incidence of abnormal vascular structures in elderly patients with vertebrobasilar arterial insufficiency ( vbi ) using digital subtraction angiography ( dsa ) and to study the clinical value of dsa 摘要目的应用数字减影主动脉弓及全脑血管造影方法观察老年椎基底动脉供血不足患者的血管结构异常表现,探讨其在临床上的应用价值。