The design and application of a diffusion tensor informed finite-element model for exploration of uniaxially prestressed muscle architecture in magnetic resonance imaging
The design and application of a diffusion tensor informed finite-element model for exploration of uniaxially prestressed muscle architecture in magnetic resonance imaging
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DOI：
10.1007/s00366-022-01690-x
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发表时间：
2022-06-30
影响因子：
8.7
通讯作者：
Royston, Thomas
中科院分区：
文献类型：
--
作者：
Crutison, Joseph;Royston, Thomas
有限元模型与医学成像的结合对我们理解组织力学做出了有价值的贡献。近年来，扩散张量成像有助于模拟大脑中的轴突束，以测量与创伤性脑损伤相关的机械应力。其他生物系统和诊断技术可以从这种方法中受益。动态弹性成像是一种相位对比成像技术，其中对比度与成像组织的机械特性（弹性和粘度）有关。通过求解基于机械波运动的逆系统来获得机械特性，通常是在假设组织是均匀的、各向同性的并且没有初始（预）应力或应变的情况下。然而，生物组织很少具有所有这三种性质，这些假设的不准确程度可能导致估计不准确。肌肉通常违反所有三个主要假设，需要更精确的方法来估计弹性模量。使用基于磁共振的扩散张量（DT）成像来通知对象特定的有限元（FE）模型的生成，通过明确地适应肌肉结构的变化来解决这个问题。这允许对预应力波动进行更稳健的分析，同时补偿由载荷引起的情况几何变化。所提出的工作演示了从DT成像到FE模型的管道，以及与类似MR弹性成像实验的比较。这项工作将有助于发展各向异性和预应力相关的反演算法，因此，提高肌肉弹性和粘性模量估计的准确性。
The combination of finite-element models with medical imaging has been a valuable contribution to our understanding of tissue mechanics. In recent years, diffusion tensor imaging has aided in modeling axonal tracts in the brain to measure mechanical stresses related to traumatic brain injuries. Other biological systems and diagnostic techniques can benefit from this approach. Dynamic elastography is a phase contrast imaging technique, where contrast is linked to the mechanical properties (elasticity and viscosity) of the imaged tissue. Mechanical properties are obtained from solving an inverse system based on mechanical wave motion, typically under the assumption that the tissue is homogeneous, isotropic and without initial (pre) stresses or strains. Biological tissues, however, rarely have all three of these properties and the degree to which these assumptions are inaccurate can lead to poor estimates. Muscle typically violates all three major assumptions and requires more refined approaches for elastic moduli estimation. using magnetic resonance-based diffusion tensor (DT) imaging to inform the generation of subject-specific finite-element (FE) models addresses this problem by explicitly accommodating for variations in muscle architecture. This allows for a more robust analysis of prestressed wave motion while compensating for situational geometric changes induced by the loading. The presented work demonstrates a pipeline from DT imaging to FE models and the resulting comparisons with analogous MR elastography experiments. This work will help in developing anisotropic and prestressed relevant inversion algorithms, therefore, improving the accuracy of muscle elastic and viscous moduli estimates.