非对比增强心电门控磁共振血管成像对下肢动脉病变的诊断价值

Diagnostic value of non-contrast-enhanced ECG-gated MR angiography in lower extremity artery disease

目的:评估非对比增强心电门控磁共振血管成像(NCE-MRA)对下肢动脉病变的诊断价值。方法:对30例下肢动脉病变病人行下肢动脉NCE-MRA及对比增强磁共振血管成像(CE-MRA)检查,比较2种检查方法的检查时间,并从动脉解剖显示、静脉污染、软组织伪影方面采用5分法进行图像质量评分,以CE-MRA作为参照标准,评价NCE-MRA各节段血管的狭窄程度,计算NCE-MRA诊断各节段动脉显著性狭窄的敏感度、特异度、阳性预测值、阴性预测值和诊断准确性,并评价NCE-MRA和CE-MRA诊断下肢动脉显著性狭窄的一致性。结果:CE-MRA检查时间明显短于NCE-MRA(P<0.01)。30例病人共计480个动脉节段,其中CE-MRA有477个(99.4%)动脉节段、NCE-MRA有446个(92.9%)动脉节段符合诊断要求,CE-MRA腹盆段、大腿段、小腿段三个节段的图像质量评分均优于NCE-MRA(P<0.05～P<0.01)。以CE-MRA为参照标准,NCE-MRA对显著性狭窄动脉高估37个,低估13个,敏感度、特异度、阳性预测值、阴性预测值和准确性分别为93.97%、92.21%、90.78%、94.94%、93.00%,2种方法诊断下肢动脉显著性狭窄的一致性较好(Kappa=0.859,P<0.05)。结论:NCE-MRA是一种安全、有效的检查技术,在显示下肢动脉显著性狭窄方面有较高的准确性,可以为肾功能不全或不能使用对比剂的病人提供一种下肢动脉影像检查替代方法。

Objective:To evaluate the diagnostic value of non-contrast-enhanced ECG-gated MR angiography(NCE-MRA)in lower extremity artery disease.Methods:The lower extremity artery disease in 30 patients was detected using NCE-MRA and contrast-enhanced MR angiography(CE-MRA),respectively.The detection time between two examination methods was compared.The image quality was scored using 5-point scale according to the arterial display,venous infection and soft tissue artifacts.CE-MRA was set as the standard,the stenosis degree of each segment of blood vessel of NCE-MRA was assessed.The sensitivity,specificity,positive predictive value,negative predictive value and diagnostic accuracy of severe stenosis artery diagnosed by NCE-MRA were calculated.The consistency of NCE-MRA and CE-MRA in diagnosis of severe stenosis was analyzed.Results:The examination time of CE-MRA was significantly shorter than that of NCE-MRA(P<0.01).Four hundred and eighty segmental arteries in 30 patients were identified,and 477 segmental arteries of CE-MRA(99.4%)and 466 segmental arteries of NCE-MRA(92.9%)were accord with diagnostic requirements.The image quality scores of CE-MRA in abdomen-pelvis,thigh and calf vessels were better than those of NCE-MRA(P<0.05 to P<0.01).CE-MRA was set as the standard,37 and 13 severe stenosis arteries were over and under estimated by NCE-MRA,respectively.The sensitivity,specificity,positive predictive value,negative predictive value and diagnostic accuracy of NCE-MRA were 93.97%,92.21%,90.78%,94.94%and 93.00%,respectively.The consistency of two methods in the diagnosis of severe arterial stenosis of the lower extremity was good(Kappa=0.859,P<0.05).Conclusions:NCE-MRA is a safe and effective technique.The accuracy of NCE-MRA in showing severe stenosis of lower limb artery is high,which can be used as an alternative method for arteriography of lower extremity in patients with renal insufficiency or not suitable for contrast agents.