基于多序列磁共振血管壁成像的下肢动脉病变诊断研究

Diagnosis of lower extremity arterial disease based on multi-sequence magnetic resonance vessel wall imaging

目的 本研究旨在探讨基于延迟进动定制激发(delay alternating with nutation for tailored excitation, DANTE)和可变翻转角快速自旋回波(sampling perfection with application-optimized contrasts by using different flip angle evolutions, SPACE)的多序列磁共振血管壁成像(magnetic resonance vessel wall imaging, MR-VWI)对下肢动脉病变(lower extremity arterial disease,LEAD)的诊断价值。材料与方法 回顾性分析了57例LEAD患者和26例无LEAD患者的病例及影像资料。所有患者均在3.0 T MRI设备上接受了T2快速自旋回波序列(turbo spin echo, TSE)、T1w DANTE-SPACE、对比增强(contrast enhancement, CE)T1w DANTE-SPACE和CE磁共振血管造影(magnetic resonance angiography, MRA)MR-VWI扫描。两名放射科医师在双盲条件下分别测量了T1w DANTE-SPACE和T2w TSE序列图像相应位置的管腔面积(lumen area, LA)、管壁面积(vessel wall area,VWA)、平均管壁厚度(average vessel wall, AVW)和最大管壁厚度(maximum vessel wall, MVW)等形态学指标。每位医师在3周间隔后对相同指标进行了重复测量。采用组内相关系数(intra-class correlation coefficients, ICC)和Bland-Altman方法评估了两种扫描技术以及不同组别之间的T1w DANTE-SPACE形态学测量指标的观察者一致性和可重复性。使用受试者工作特征(receiveroperatingcharacteristic,ROC)曲线评估了准确性。结果T1wDANTE-SPACE与T2wTSE成像技术的信噪比(signal-to-noise ratio, SNR)和对比度比(contrast-to-noise ratio, CNR)差异有统计学意义(P<0.05),两名观察者对形态学测量指标的ICC值在0.85~0.99之间。在不同组别中,T1w DANTE-SPACE形态学测量指标的两次测量ICC值为0.90~0.99。Bland-Altman分析显示,观察者间和两次测量间的大部分形态学测量指标均在95%的一致性限度内。T1w DANTE-SPACE技术在LEAD组不同血管节段的形态学指标ROC曲线下面积(area under the curve, AUC)分别为0.904 [95%置信区间(confidence interval, CI):0.825~0.983]和0.905 (95%CI:0.835~0.976)。当腘小腿动脉段的血管壁厚度为1.00 mm,LA为10.88 mm时,LEAD的敏感度分别为79.2%和85.4%,特异度分别为96.2%和92.3%,阳性预测值分别为97.4%和95.3%,阴性预测值分别为71.4%和77.4%。结论 多序列MR-VWI在评估LEAD斑块形态学指标方面表现出良好的重复性和高准确性,支持其在LEAD的MRI检查中的应用。

Objective:To investigate the clinical utility of delay alternating with nutation for tailored excitation(DANTE)and sampling perfection with application-optimized contrasts by using different flip angle evolutions(SPACE)in multi-sequence magnetic resonance vessel wall imaging(MR-VWI)for diagnosing lower extremity arterial disease(LEAD).Materials and Methods:The case and imaging data from 57 LEAD patients and 26 without LEAD patients were retrospectively included.All patients underwent T2-weighted turbo spin echo(T2w-TSE),T1-weighted DANTE-SPACE,contrast-enhanced T1-weighted DANTE-SPACE,and contrast-enhanced magnetic resonance angiography(CE-MRA)MR-VWI scans on 3.0 T MRI equipment.Lumen area(LA),vessel wall area(VWA),and average vessel wall thickness(AVW)were measured by two radiologists in a double-blind procedure.The intra-class correlation coefficient(ICC)and Bland-Altman method were used to assess inter-observer agreement and agreement between different scanning techniques.Receiver operating characteristic(ROC)curves were used to evaluate accuracy.Results:Signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)values were significantly different between T1w DANTE-SPACE and 2D TSE imaging techniques(P<0.05).ICC values for morphological measurements ranged from 0.85 to 0.99 between two observers and from 0.90 to 0.99 for repeated measurements.Bland-Altman analysis showed good agreement between observers and measurements.The T1w DANTE-SPACE technique was applied to the morphological measurement index ROC of different vascular segments in the LEAD group,resulting in area under the curve(AUC)values of 0.904[95%confidence interval(CI):0.825-0.983]and 0.905(95%CI:0.835-0.976),respectively.When the vessel wall thickness of the popliteal artery segment was 1.00 mm and the lumen area(LA)was 10.88 mm,serving as the critical values,the sensitivity for LEAD was 79.2%and 85.4%,the specificity was 96.2%and 92.3%,the positive predictive value was 97.4%and 95.3%,and the negative predictive value was 71.4%and 77.4%,respectively.Conclusions:Multi-sequence MR-VWI demonstrates good repeatability and high accuracy in evaluating morphological indicators of LEAD plaques,supporting its application in MRI examinations of LEAD.