In vivo liver tissue mechanical properties by transient elastography: Comparison with dynamic mechanical analysis
In vivo liver tissue mechanical properties by transient elastography: Comparison with dynamic mechanical analysis
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DOI：
10.3233/bir-2011-0584
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发表时间：
2011-01-01
期刊：
影响因子：
1.1
通讯作者：
Willinger, Remy
中科院分区：
文献类型：
--
作者：
Chatelin, Simon;Oudry, Jennifer;Willinger, Remy
了解人体肝脏的力学特性是其医学应用或冲击生物力学数值建模的最关键方面之一。通常，模型本构关系来自体外数据。然而，肝脏的弹性特性在死亡后可能会随着时间的推移而发生显着变化。此外，在文献中报道的体外肝脏弹性性能往往没有定量地与同一器官的体内肝脏机械性能进行比较。在这项研究中，这两个步骤进行了调查，对猪肝。通过瞬态弹性成像（TE）和动态力学分析（DMA）测量猪肝的弹性特性（由剪切模量G给出）。对体内和体外肝脏进行剪切模量测量，比较TE和DMA方法，研究测试条件对肝脏粘弹性的影响。体外实验结果表明，TE法和DMA法测得的弹性性能基本一致。在0.1至4 Hz的频率范围内的肝组织可以通过双模式弛豫模型来建模。此外，结果表明，肝脏是均匀的，各向同性的，比粘性更弹性。最后，它是在这项研究中所示，TE和DMA获得的粘弹性能显着变化与死后的时间和边界条件。
Understanding the mechanical properties of human liver is one of the most critical aspects of its numerical modeling for medical applications or impact biomechanics. Generally, model constitutive laws come from in vitro data. However, the elastic properties of liver may change significantly after death and with time. Furthermore, in vitro liver elastic properties reported in the literature have often not been compared quantitatively with in vivo liver mechanical properties on the same organ. In this study, both steps are investigated on porcine liver. The elastic property of the porcine liver, given by the shear modulus G, was measured by both Transient Elastography (TE) and Dynamic Mechanical Analysis (DMA). Shear modulus measurements were realized on in vivo and in vitro liver to compare the TE and DMA methods and to study the influence of testing conditions on the liver viscoelastic properties. In vitro results show that elastic properties obtained by TE and DMA are in agreement. Liver tissue in the frequency range from 0.1 to 4 Hz can be modeled by a two-mode relaxation model. Furthermore, results show that the liver is homogeneous, isotropic and more elastic than viscous. Finally, it is shown in this study that viscoelastic properties obtained by TE and DMA change significantly with post mortem time and with the boundary conditions.