三维心电门控屏气MRA诊断肾动脉狭窄

Diagnosis of Renal Artery Stenosis with 3D ECG-gated breath-hold MR Angiograpy

目的:评价三维心电门控FIESTA序列作为一种无需造影剂的MRA技术对肾动脉显示及狭窄诊断的准确性和实用性。材料和方法:连续6 0例临床有高血压/慢性肾功能不全表现患者行肾动脉三维心电门控屏气MRA( 3DECG gatedbreath holdMRA)和三维增强MRA( 3DCE MRA)对照检查。两位有经验的医师分别独立评价两种技术的重建图像并描述肾动脉表现,包括正常、分支显示程度、早期分支、显示副肾动脉、显著狭窄( >50 % )和动脉硬化(轻度狭窄)。结果:3DCE MRA检查中有2例因未能屏气图像明显模糊,1例因高压注射时造影剂漏出检查失败;3DECG gatedMRA检查中1例因身体过度虚弱而终止检查。3DCE MRA有6 1 ( 6 1 /1 1 1 )支显示到肾段动脉,9( 9/1 1 1 )支显示到亚段肾动脉;3DECG gatedMRA有56 ( 56 /1 1 1 )支显示到肾段动脉,2 ( 2 /1 1 1 )支显示到亚段肾动脉。以3DCE MRA为标准,3DECG gatedMRA诊断肾动脉显著狭窄的准确性、敏感性和特异性分别为94 .6 %、82 .6 %和97.7% ,优劣性检验χ2 =0 .1 6 6 7,P >0 .0 5。结论:以3DFIESTA为基础的三维心电门控屏气MRA无需造影剂,诊断肾动脉狭窄与三维增强MRA有很高的一致性,可以作为肾动脉狭窄诊断的筛查和补充手段。

Purpose: To evaluate the validity of ECG-gated 3D FIESTA sequence as a non-enhanced MRA technique in diagnosing renal artery stenosis. Materials and Methods: Consecutively 60 patients tended comparative ECG-gated breath-hold MRA and 3D CE-MRA. Two independent experienced doctors separately evaluated the MIP reformatted images and described the renal arteries manifestations including normal, extension degree, early branching, accessory artery delineation, significant stenosis(>50%) and sclerosing appearance(mild stenosis). Results: There are 2 cases of 3D CE-MRA images blurring severely due to failed cooperation breath-hold when starting contrast scanning. One case failed due to power injection unsuccessful. One case stopped examination from ECG-gated breath-hold MRA because of health problem. Segmental and subsegmental renal artery can be demonstrated with 3D CE-MRA in 61(61/111) and 9(9/111) branches while with ECG-gated breath-hold MRA in 56(56/111) and 2(2/111) branches respectively. For diagnosing significant stenosis, the accuracy, sensitivity and specificity of ECG-gated MRA was 94.6%, 82.6% and 97.7% respectively when taken 3D CE-MRA as gold standard. χ 2=0.1667, P>0.05. Conclusion: ECG-gated breath-hold MRA has no potential contrast agent harms to patients and convenient for repeat. It has a relative high consistence with 3D CE-MRA in diagnosing renal arery stenosis and can be taken as one of screening methods.