Stress distributions and material properties determined in articular cartilage from MRI-based finite strains
Stress distributions and material properties determined in articular cartilage from MRI-based finite strains
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DOI：
10.1016/j.jbiomech.2011.08.005
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发表时间：
2011-10-13
影响因子：
2.4
通讯作者：
Neu, Corey P.
中科院分区：
文献类型：
--
作者：
Butz, Kent D.;Chan, Deva D.;Neu, Corey P.
通过磁共振成像(MRI)对生物材料和组织中的有限应变进行非侵入性测量，可以对应力分布和材料特性进行数学估计。这种方法允许以传统机械测试或有限元技术不可能实现的非接触式和特定于患者的建模。在这里，我们使用三种本构关系(即线性Hookean和非线性Neo-Hookean和Mooney Rivlin)以及已知载荷条件和基于MRI的有限应变来估计胫股关节关节软骨的应力模式和材料特性。用位移编码的磁共振成像来确定幼猪关节中的二维有限应变，并使用迭代技术来估计应力分布和材料特性，其中定义了本构关系。应力分布在所有关系中都是一致的，尽管应力大小不同。股骨和胫骨软骨的材料特性被发现与文献报道的一致。此外，Hookean和Neo-Hookean的应力估计，而不是Mooney-Rivlin关系的应力估计，与基于有限元的模拟一致。非线性Neo-Hookean关系为使用基于MRI的二维有限应变来表征复杂的和空间相关的应力提供了最合适的模型。这些结果证明了一种新的、计算高效的技术的可行性，该技术将基于MRI的变形与数学建模相结合，以非侵入性地评估生物组织和材料的力学行为。(C)2011爱思唯尔有限公司。保留所有权利。
The noninvasive measurement of finite strains in biomaterials and tissues by magnetic resonance imaging (MRI) enables mathematical estimates of stress distributions and material properties. Such methods allow for non-contact and patient-specific modeling in a manner not possible with traditional mechanical testing or finite element techniques. Here, we employed three constitutive (i.e. linear Hookean, and nonlinear Neo-Hookean and Mooney Rivlin) relations with known loading conditions and MRI-based finite strains to estimate stress patterns and material properties in the articular cartilage of tibiofemoral joints. Displacement-encoded MRI was used to determine two-dimensional finite strains in juvenile porcine joints, and an iterative technique estimated stress distributions and material properties with defined constitutive relations. Stress distributions were consistent across all relations, although the stress magnitudes varied. Material properties for femoral and tibial cartilage were found to be consistent with those reported in literature. Further, the stress estimates from Hookean and Neo-Hookean, but not Mooney-Rivlin, relations agreed with finite element-based simulations. A nonlinear Neo-Hookean relation provided the most appropriate model for the characterization of complex and spatially dependent stresses using two-dimensional MRI-based finite strain. These results demonstrate the feasibility of a new and computationally efficient technique incorporating MRI-based deformation with mathematical modeling to non-invasively evaluate the mechanical behavior of biological tissues and materials. (C) 2011 Elsevier Ltd. All rights reserved.