Harrigan Timothy P, Konofagou Elisa E
Exponent Failure Analysis Associates, 21 Strathmore Road, Natick, MA 10760, USA.
J Biomech. 2004 Aug;37(8):1215-21. doi: 10.1016/j.jbiomech.2003.12.027.
The local material stiffness of tissues is a well-known indicator of pathology, with locally stiffer tissue related to the possible presence of an abnormal growth in otherwise compliant tissue. Elastography is a non-invasive technique for measuring displacement distributions in loaded tissues within a medical imaging context. From these measured displacement fields, estimated for local strain have been made using well-studied techniques, but the calculation of elastic modulus has been difficult. In this study we show a method for estimating local tissue elastic modulus that gives numerically stable and robust results in test cases, and that is numerically efficient. The method assumes the tissue is isotropic and it requires an independent estimate of tissue Poisson's ratio, but the method reaches a stable result when the estimated Poisson's ratio is in error, and the resulting estimates are not very sensitive to the assumed value.
组织的局部材料刚度是一种众所周知的病理学指标，局部较硬的组织与原本顺应性良好的组织中可能存在异常生长有关。弹性成像技术是一种在医学成像环境中测量加载组织中位移分布的非侵入性技术。根据这些测量的位移场，已经使用经过充分研究的技术进行了局部应变估计，但弹性模量的计算一直很困难。在本研究中，我们展示了一种估计局部组织弹性模量的方法，该方法在测试案例中给出了数值稳定且可靠的结果，并且在数值上是高效的。该方法假设组织是各向同性的，并且需要对组织泊松比进行独立估计，但当估计的泊松比存在误差时，该方法仍能得到稳定的结果，并且所得估计值对假设值不太敏感。
