INSERM U678/UPMC Universite Paris 6, Hôpital Européen Georges Pompidou, 20 Rue Leblanc, Paris, France.
Circ Cardiovasc Imaging. 2012 Sep 1;5(5):604-12. doi: 10.1161/CIRCIMAGING.111.971218. Epub 2012 Jul 13.
Accurate quantification of aortic valve stenosis (AVS) is needed for relevant management decisions. However, transthoracic Doppler echocardiography (TTE) remains inconclusive in a significant number of patients. Previous studies demonstrated the usefulness of phase-contrast cardiovascular magnetic resonance (PC-CMR) in noninvasive AVS evaluation. We hypothesized that semiautomated analysis of aortic hemodynamics from PC-CMR might provide reproducible and accurate evaluation of aortic valve area (AVA), aortic velocities, and gradients in agreement with TTE.
We studied 53 AVS patients (AVA(TTE)=0.87±0.44 cm(2)) and 21 controls (AVA(TTE)=2.96±0.59 cm(2)) who had TTE and PC-CMR of aortic valve and left ventricular outflow tract on the same day. PC-CMR data analysis included left ventricular outflow tract and aortic valve segmentation, and extraction of velocities, gradients, and flow rates. Three AVA measures were performed: AVA(CMR1) based on Hakki formula, AVA(CMR2) based on continuity equation, AVA(CMR3) simplified continuity equation=left ventricular outflow tract peak flow rate/aortic peak velocity. Our analysis was reproducible, as reflected by low interoperator variability (<4.56±4.40%). Comparison of PC-CMR and TTE aortic peak velocities and mean gradients resulted in good agreement (r=0.92 with mean bias=-29±62 cm/s and r=0.86 with mean bias=-12±15 mm Hg, respectively). Although good agreement was found between TTE and continuity equation-based CMR-AVA (r>0.94 and mean bias=-0.01±0.38 cm(2) for AVA(CMR2), -0.09±0.28 cm(2) for AVA(CMR3)), AVA(CMR1) values were lower than AVA(TTE) especially for higher AVA (mean bias=-0.45±0.52 cm(2)). Besides, ability of PC-CMR to detect severe AVS, defined by TTE, provided the best results for continuity equation-based methods (accuracy >94%).
Our PC-CMR semiautomated AVS evaluation provided reproducible measurements that accurately detected severe AVS and were in good agreement with TTE.
准确评估主动脉瓣狭窄（AVS）对于相关的管理决策至关重要。然而，经胸多普勒超声心动图（TTE）在很大一部分患者中仍无法得出明确结论。先前的研究表明，相位对比心血管磁共振（PC-CMR）在无创性 AVS 评估中具有一定作用。我们假设，从 PC-CMR 半自动分析主动脉血流动力学可以提供重复性好且准确的主动脉瓣口面积（AVA）、主动脉速度和梯度评估，与 TTE 结果一致。
我们研究了 53 例 AVS 患者（AVA(TTE)=0.87±0.44 cm(2)）和 21 例对照者（AVA(TTE)=2.96±0.59 cm(2)），这些患者均于同日接受了 TTE 和 PC-CMR 主动脉瓣和左心室流出道检查。PC-CMR 数据分析包括左心室流出道和主动脉瓣分割，以及速度、梯度和流量提取。进行了三种 AVA 测量：基于 Hakki 公式的 AVA(CMR1)、基于连续性方程的 AVA(CMR2)和简化连续性方程的 AVA(CMR3)=左心室流出道峰值流速/主动脉峰值速度。我们的分析具有可重复性，这反映在操作员间的变异性较低（<4.56±4.40%）。PC-CMR 和 TTE 主动脉峰值速度和平均梯度的比较结果显示出良好的一致性（r=0.92，平均偏差=-29±62 cm/s；r=0.86，平均偏差=-12±15 mmHg）。虽然 TTE 与基于连续性方程的 CMR-AVA（AVA(CMR2)的 r>0.94，平均偏差=-0.01±0.38 cm(2)；AVA(CMR3)的 r>0.94，平均偏差=-0.09±0.28 cm(2)）之间存在良好的一致性，但 AVA(CMR1)值低于 AVA(TTE)，尤其是对于较高的 AVA（平均偏差=-0.45±0.52 cm(2)）。此外，基于连续性方程的方法对 TTE 定义的严重 AVS 的检测能力最好（准确性>94%）。
我们的 PC-CMR 半自动 AVS 评估提供了可重复的测量结果，可准确检测严重 AVS，并与 TTE 结果具有良好的一致性。
