Purpose: To optimize spiral CT angiography (SCTA) technique, to evaluate value of SCTA application and give more informations about how to select SCTA or DSA for large aneurysms reasonably.

• 目的:探讨大动脉瘤螺旋CT 血管造影(SCTA) 检查技术和应用价值,为合理选择SCTA 和DSA 检查方法提供依据。