Abstract:
Three-dimensional echocardiography (3D ECHO) and magnetic resonance (MR) imaging are frequently used in patients and animals to evaluate heart functions. Inverse finite element (FE) modeling is increasingly applied to MR images to quantify left ventricular (LV) function and estimate myocardial contractility and other cardiac biomarkers. It remains unclear, however, as to whether myocardial contractility derived from the inverse FE model based on 3D ECHO images is comparable to that derived from MR images. To address this issue, we developed a subject-specific inverse FE model based on 3D ECHO and MR images acquired from seven healthy swine models to investigate if there are differences in myocardial contractility and LV geometrical features derived using these two imaging modalities. We showed that end-systolic and end-diastolic volumes derived from 3D ECHO images are comparable to those derived from MR images (R2=0.805 and 0.969, respectively). As a result, ejection fraction from 3D ECHO and MR images are linearly correlated (R2=0.977) with the limit of agreement (LOA) ranging from -17.95% to 45.89%. Using an inverse FE modeling to fit pressure and volume waveforms in subject-specific LV geometry reconstructed from 3D ECHO and MR images, we found that myocardial contractility derived from these two imaging modalities are linearly correlated with an R2 value of 0.989, a gradient of 0.895, and LOA ranging from -6.11% to 36.66%. This finding supports using 3D ECHO images in image-based inverse FE modeling to estimate myocardial contractility.
摘要:
在患者和动物中经常使用三维超声心动图(3DECHO)和磁共振(MR)成像来评估心脏功能。反向有限元(FE)建模越来越多地应用于MR图像,以量化左心室(LV)功能并评估心肌收缩力和其他心脏生物标志物。目前还不清楚,然而,关于基于3DECHO图像的逆FE模型得出的心肌收缩力是否与MR图像得出的心肌收缩力相当。为了解决这个问题,我们基于从7个健康猪模型获得的3DECHO和MR图像,开发了针对特定受试者的逆FE模型,以研究使用这两种成像方式得出的心肌收缩力和LV几何特征是否存在差异.我们表明,从3DECHO图像得出的收缩末期和舒张末期容积与从MR图像得出的容积相当(分别为R2=0.805和0.969)。因此,3DECHO和MR图像的射血分数呈线性相关(R2=0.977),一致性极限(LOA)范围为-17.95%至45.89%。使用逆FE建模来拟合从3DECHO和MR图像重建的受试者特定LV几何结构中的压力和体积波形。我们发现,从这两种成像方式得出的心肌收缩力与0.989的R2值,0.895的梯度和-6.11%~36.66%的LOA线性相关.这一发现支持在基于图像的逆FE建模中使用3DECHO图像来估计心肌收缩力。