Department of Radiology, Stanford University, Stanford, CA, 94305, USA.
Division of Radiology, Veterans Administration Health Care System, Palo Alto, CA, 94304, USA.
Ann Biomed Eng. 2023 Jul;51(7):1574-1587. doi: 10.1007/s10439-023-03164-7. Epub 2023 Mar 13.
Impaired cardiac filling in response to increased passive myocardial stiffness contributes to the pathophysiology of heart failure. By leveraging cardiac MRI data and ventricular pressure measurements, we can estimate in vivo passive myocardial stiffness using personalized inverse finite element models. While it is well-known that this approach is subject to uncertainties, only few studies quantify the accuracy of these stiffness estimates. This lack of validation is, at least in part, due to the absence of ground truth in vivo passive myocardial stiffness values. Here, using 3D printing, we created soft, homogenous, isotropic, hyperelastic heart phantoms of varying geometry and stiffness and simulate diastolic filling by incorporating the phantoms into an MRI-compatible left ventricular inflation system. We estimate phantom stiffness from MRI and pressure data using inverse finite element analyses based on a Neo-Hookean model. We demonstrate that our identified softest and stiffest values of 215.7 and 512.3 kPa agree well with the ground truth of 226.2 and 526.4 kPa. Overall, our estimated stiffnesses revealed a good agreement with the ground truth ([Formula: see text] error) across all models. Our results suggest that MRI-driven computational constitutive modeling can accurately estimate synthetic heart material stiffnesses in the range of 200-500 kPa.
心肌顺应性降低导致心肌僵硬度增加，进而引起心力衰竭的病理生理学改变。通过利用心脏磁共振成像（cardiac MRI）数据和心室压力测量，我们可以使用个性化的逆有限元模型来估计体内被动心肌僵硬度。虽然众所周知，这种方法存在不确定性，但只有少数研究对这些僵硬度估计的准确性进行了量化。这种缺乏验证的情况至少部分归因于缺乏体内被动心肌僵硬度的真实值。在这里，我们使用 3D 打印技术创建了具有不同几何形状和刚度的柔软、均匀、各向同性、超弹性心脏模型，并通过将模型纳入与 MRI 兼容的左心室充气系统来模拟舒张期充盈。我们使用基于 Neo-Hookean 模型的逆有限元分析从 MRI 和压力数据估计模型的僵硬度。我们证明，我们识别出的最柔软和最硬的值分别为 215.7 和 512.3 kPa，与真实值 226.2 和 526.4 kPa 非常吻合。总的来说，我们的估计僵硬度与所有模型的真实值之间具有良好的一致性([Formula: see text]误差)。我们的研究结果表明，基于 MRI 的计算本构模型可以准确估计 200-500 kPa 范围内的合成心脏材料的僵硬度。
