Carstensen Edwin L, Parker Kevin J
Department of Electrical and Computer Engineering and Department of Biomedical Engineering, University of Rochester, Rochester, New York, USA.
Department of Electrical and Computer Engineering and Department of Biomedical Engineering, University of Rochester, Rochester, New York, USA.
Ultrasound Med Biol. 2014 Apr;40(4):655-74. doi: 10.1016/j.ultrasmedbio.2013.11.001.
This review considers three general classes of physical as opposed to phenomenological models of the shear elasticity of tissues. The first is simple viscoelasticity. This model has a special role in elastography because it is the language in which experimental and clinical data are communicated. The second class of models involves acoustic relaxation, in which the medium contains inner time-dependent systems that are driven through the external bulk medium. Hysteresis, the phenomenon characterizing the third class of models, involves losses that are related to strain rather than time rate of change of strain. In contrast to the vast efforts given to tissue characterization through their bulk moduli over the last half-century, similar research using low-frequency shear data is in its infancy. Rather than a neat summary of existing facts, this essay is a framework for hypothesis generation-guessing what physical mechanisms give tissues their shear properties.
本综述探讨了与组织剪切弹性的唯象模型相对的三类一般物理模型。第一类是简单粘弹性。该模型在弹性成像中具有特殊作用，因为它是交流实验和临床数据的语言。第二类模型涉及声学弛豫，其中介质包含通过外部体介质驱动的内部时间相关系统。滞后现象是第三类模型的特征，它涉及与应变而非应变变化率相关的损耗。与过去半个世纪通过体积模量进行组织表征的大量努力相比，利用低频剪切数据的类似研究尚处于起步阶段。本文并非对现有事实的简洁总结，而是一个假设生成的框架——猜测是哪些物理机制赋予组织剪切特性。
