Materials and Methods:1. 32 cases of healthy volunteers were performed to obtain the images of the cervical arteries with MRA by using different imaging sequences and imaging parameters,and their effects on the MRA images were observed.

• 材料和方法：1、健康自愿者32例，分别用不同成像序列和成像参数行颈动脉MRA检查，观察它们对正常颈动脉MRA图像的影响。