Anisotropic polyvinyl alcohol hydrogel phantom for shear wave elastography in fibrous biological soft tissue: a multimodality characterization
Anisotropic polyvinyl alcohol hydrogel phantom for shear wave elastography in fibrous biological soft tissue: a multimodality characterization
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DOI：
10.1088/0031-9155/59/22/6923
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发表时间：
2014-11-21
影响因子：
3.5
通讯作者：
Pernot, Mathieu
中科院分区：
文献类型：
--
作者：
Chatelin, Simon;Bernal, Miguel;Pernot, Mathieu
横波弹性成像技术提供了软组织弹性特性的定量测量。肌腱、肌肉和大脑组织都是由纤维组成的，纤维对其力学行为具有很强的各向异性效应。目前，这些组织不能用现有的弹性成像模型准确地表示。最近，一种新的正交异性水凝胶模拟软组织的方法被开发出来（million et al . 2006 J. Biomed.）。板牙。Res. B 305-11)。在聚乙烯醇（PVA）低温凝胶中，机械各向异性是通过拉伸聚合物链的物理交联在冻融循环中引起的。在目前的研究中，我们提出了一种原始的多模态成像表征这种新的横向各向同性（TI） PVA水凝胶。与采用类似成像和流变学方案的各向同性聚乙烯醇水凝胶相比，采用多种不同尺度的技术研究了多种性能。利用超声横波成像技术、全场光学相干层析成像（FFOCT）应变成像技术和经典线性流变学动态力学分析技术研究了材料的各向异性力学（动、静态）特性。利用FFOCT体积成像和后向散射张量成像分别测量了各向异性光学和超声空间相干性。机械性能和光学性能的相关性证明了这些技术在多尺度范围内研究各向异性的互补性，以及这种TI模体作为剪切波弹性学应用的纤维组织模拟模体的潜力。
Shear wave elastography imaging techniques provide quantitative measurement of soft tissues elastic properties. Tendons, muscles and cerebral tissues are composed of fibers, which induce a strong anisotropic effect on the mechanical behavior. Currently, these tissues cannot be accurately represented by existing elastography phantoms. Recently, a novel approach for orthotropic hydrogel mimicking soft tissues has been developed (Millon et al 2006 J. Biomed. Mater. Res. B 305-11). The mechanical anisotropy is induced in a polyvinyl alcohol (PVA) cryogel by stretching the physical crosslinks of the polymeric chains while undergoing freeze/thaw cycles. In the present study we propose an original multimodality imaging characterization of this new transverse isotropic (TI) PVA hydrogel. Multiple properties were investigated using a large variety of techniques at different scales compared with an isotropic PVA hydrogel undergoing similar imaging and rheology protocols. The anisotropic mechanical (dynamic and static) properties were studied using supersonic shear wave imaging technique, full-field optical coherence tomography (FFOCT) strain imaging and classical linear rheometry using dynamic mechanical analysis. The anisotropic optical and ultrasonic spatial coherence properties were measured by FFOCT volumetric imaging and backscatter tensor imaging, respectively. Correlation of mechanical and optical properties demonstrates the complementarity of these techniques for the study of anisotropy on a multi-scale range as well as the potential of this TI phantom as fibrous tissue-mimicking phantom for shear wave elastographic applications.