MRA和彩色双功能多普勒超声诊断颈动脉狭窄的价值

目的比较和分析颈动脉狭窄的MRA特征和彩色双功能多普勒超声的表现.材料和方法25例颈动脉狭窄均由彩色多普勒确诊和分级.MRA扫描序列为2维时间飞越技术.结果25例颈动脉狭窄MRA信号缺损大于彩色多普勒超声的斑块长度.9根血流信号中断与脉冲多普勒的舒张期和收缩期血流峰速相关(r=0.685;r=0.828),是血流高速的结果,是中、重度颈动脉狭窄的特征.血管扩张是中度动脉狭窄的重要表现.颈动脉血流消失且无血流重现是血管闭塞的特异征象.结论二维时间飞越MRA在发现和诊断颈动脉狭窄时有一定的临床价值.

The Role of MR Angiography for Carotid Artery Stenosis Comparing with Color Doppler Ultrasonography

Purpose: To compare the findings of MR angiography with color doppler ultrasonography in carotid artery stenosis. Materials and Methods:25 patients with carotid artery stenosis were studied. 2 dimensional time of flight MR angiographic technique was performed. All carotid stenoses were diagnosed and confirmed with Acuson-128 color doppler ultrasound. Results: Signal defects along the vascular wall indicating the plaques appeared in 25 cases of stenosis. Defect length on MRA was longer than the actual plaques on color duppler sonogra phy. Flow gap was the morphologic characteristics of moderate or severe stenosis deriving from accelerating blood, which was correlated with diastolic flow velocity and systolic flow velocity of carotid artery on pulse duppler, (r_0.05 = 0. 685, r_0.01 = 0.828, rspectively). Dilation fol lowing stenosed part was the important sign of moderate stenosis. Occlusion showed specifically the complete absence of blood signal intensity distal to the occlusion without recovery of flowing signal intensity. Conclusion: Two dimensional time-of-flight MR angiography is a usefull approach for helping detect and grade the seventy of stenosis of carotid artery stenosis.