Sumi C, Suzuki A, Nakayama K
Department of Electrical and Electronics Engineering, School of Science and Technology, Sophia University, Tokyo, Japan.
IEEE Trans Biomed Eng. 1995 Feb;42(2):193-202. doi: 10.1109/10.341832.
In order to obtain noninvasively quantitative static mechanical properties of living tissue, we propose a new type of inverse problem by which the spatial distribution of the relative elastic modulus of the tissue can be estimated only from the deformation or strain measurement. The living tissue is modeled as a linear isotropic incompressible elastic medium which has the spatial distribution of the shear modulus, and the deformation or strain is supposedly measured ultrasonically. Assuming that there is no mechanical source in the region of interest, we derive a set of linear equations in which unknowns are the spatial derivatives of the relative shear modulus, and the coefficients are the strain and its spatial derivatives. By solving these equations, the spatial derivatives of the relative shear modulus are determined throughout the region, from which the spatial distribution of the relative shear modulus is obtained by spatial integration. The feasibility of this method was demonstrated using the simulated deformation data of the simple inclusion problem. The proposed method seems promising for the quantitative differential diagnosis on the lesion in the tissue in vivo.
为了无创地获取活体组织的定量静态力学特性，我们提出了一种新型反问题，通过该问题仅根据变形或应变测量就可以估计组织相对弹性模量的空间分布。将活体组织建模为具有剪切模量空间分布的线性各向同性不可压缩弹性介质，并假定通过超声测量变形或应变。假设在感兴趣区域内没有机械源，我们推导了一组线性方程，其中未知数是相对剪切模量的空间导数，系数是应变及其空间导数。通过求解这些方程，确定整个区域内相对剪切模量的空间导数，通过空间积分从中获得相对剪切模量的空间分布。使用简单包含问题的模拟变形数据证明了该方法的可行性。所提出的方法对于体内组织病变的定量鉴别诊断似乎很有前景。
