目的 比较相同碘浓度下，不同的对比剂注射方案在64层螺旋CT血管造影(CTA)中对颅脑CTA图像质量的影响。方法 将100例可疑脑动脉瘤患者随机分为2组，A组以3.5ml/s的速率将70mL对比剂一次注入。B组以第一期3.5ml/s的速率 注射50mL，第二期以2.0ml/s的速率，将剩余的20mL对比剂注入。分别分析其横断位图像，MPR图像，分别测量颈动 脉分叉层面右侧颈总动脉，基底动脉，右侧大脑中动脉，窦汇的CT值，同时观察脑动脉细小分支显示情况。结果 A 组窦汇的CT值明显高于B组，(P＜0.05)各组间CT值存在显著差异。两组在各动脉的CT值无明显差别(P＞0.05)。结 论 双期注射碘对比剂在头颅CTA实际应用中静脉的干扰明显低于单期注射法，图像质量优于单期注射法。

Objective To compare the effects of different contrast media injection plan on the quality of images of 64 slice spiral CT angiography (CTA) in the same iodine concentration. Methods 100 patients with suspected cerebral aneurysms were randomly divided into two groups. Group A were injected with 70ml contrast agent at the rate of 3.5ml/s. Group B were injected with 50ml at the first stage and the rate was 3.5ml/s. Remaiding contrast agent were injected with 20ml at the second stage and the rate was 2.0ml/s. To measure the CT value of the right carotid artery in the carotid artery bifurcation level, basilar artery, right middle cerebral artery and torcula by analyze the transversal images and MPR images. To observe the cerebral artery branches display at the same time. Results The CT value of torcula in group A were significantly higher than that in group B (P<0.05) and there were statistically significant difference between the two groups.There were no significantly difference in CT value of the arteries between the two groups (P>0.05). Conclusion The venous interference by dual phase injection of iodine contrast agent in cerebral CTA was significantly lower than single phase injection.The image quality was better at the same time.