Observe the types, draining directions, dilation, tortuousity and varix in draining veins, stenosis and the location in draining veins and venous sinus, et al.

• 结果颅内脑动静脉畸形静脉引流可出现多种形式,其中深、浅静脉均引流33例,单纯浅静脉引流23例,单纯深静脉引流13例;