Validation of a Numerical Model of Skeletal Muscle Compression With MR Tagging: A Contribution to Pressure Ulcer Research
Validation of a Numerical Model of Skeletal Muscle Compression With MR Tagging: A Contribution to Pressure Ulcer Research
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DOI：
10.1115/1.2987877
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发表时间：
2008-12-01
影响因子：
1.7
通讯作者：
Oomens, C. W. J.
中科院分区：
文献类型：
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作者：
Ceelen, K. K.;Stekelenburg, A.;Oomens, C. W. J.
持续的组织压迫可导致压疮，其可在浅表或更深的组织层内开始。后一种类型包括深层组织损伤，从完整皮肤下的骨骼肌开始。由于对潜在的损害机制知之甚少，预防和早期发现是困难的。最近的体外研究和体内动物研究表明，组织变形本身可导致损伤。为了最终将损伤与变形耦合，需要进行已知内部组织变形和损伤的实验。磁共振（MR）标记和T2加权MR成像可分别用于测量组织变形和损伤，但它们不能组合在一个协议中用于测量长时间加载后的损伤。因此，开发了一个专用的有限元模型来计算损伤实验中的应变。在本研究中，这个模型，它描述了大鼠骨骼肌的压缩，验证与MR标签。将来自标记实验和模型的位移插值到网格上，随后进行处理以获得最大剪切应变。相关性分析表明，实验和数值应变之间的线性相关性。进一步发现，数值预测的准确性随着菌株的增加而降低，但阳性预测值保持合理。得出的结论是，该模型适用于计算骨骼肌组织中的应变，其中损伤是由于压缩测量。
Sustained tissue compression can lead to pressure ulcers, which can either start superficially or within deeper tissue layers. The latter type includes deep tissue injury, starting in skeletal muscle underneath an intact skin. Since the underlying damage mechanisms are poorly understood, prevention and early detection are difficult. Recent in vitro studies and in vivo animal studies have suggested that tissue deformation per se can lead to damage. In order to conclusively couple damage to deformation, experiments are required in which internal tissue deformation and damage are both known. Magnetic resonance (MR) tagging and T2-weighted MR imaging can be used to measure tissue deformation and damage, respectively, but they cannot be combined in a protocol for measuring damage after prolonged loading. Therefore, a dedicated finite element model was developed to calculate strains in damage experiments. In the present study, this model, which describes the compression of rat skeletal muscles, was validated with MR tagging. Displacements from both the tagging experiments and the model were interpolated on a grid and subsequently processed to obtain maximum shear strains. A correlation analysis revealed a linear correlation between experimental and numerical strains. It was further found that the accuracy of the numerical prediction decreased for increasing strains, but the positive predictive value remained reasonable. It was concluded that the model was suitable for calculating strains in skeletal muscle tissues in which damage is measured due to compression.