Tomographic imaging of shear modulus elasticity of biological tissue based on ultrasonic measurement of internal displacement

由于软组织弹性的变化往往与某些异常的病理过程有关，因此，触诊已成为临床上检测软组织弹性变化的主要方法。本研究的目的是表征组织弹性的基础上超声测量的内部组织变形和位移时，主要心脏搏动或外部机械力施加到软组织。提出了一种确定各向同性、非均匀、不可压缩生物软组织在机械外力作用下弹性参数的变分公式。如果知道整个组织的位移。提出了一种基于有限元的静态变形模型，用于求解组织的相对剪切模量或杨氏模量的分布。利用简单三维夹杂问题的模拟变形数据验证了该方法的可行性。结果表明 ...更多信息 相对剪切模量可以从各向同性不可压缩介质中感兴趣区域的局部位移数据中重建，并且相对剪切模量可以从仅二维位移数据中恢复到一定程度的精度。使用实时超声和从组织返回的RF回波信号序列进行肠系膜切除术，该序列被数字化以估计局部组织位移。使用RF回波包络信号的时空导数估计内部位移的2维分布，由此计算内部应变张量的分量。实验结果表明，该方法可以在5mm × 5mm的空间分辨率下估计出位移分量的二维场。基于位移图像重建了相对剪切模量的分布。软组织的弹性可以被表征为根据在接收到的RF回波信号中观察到的局部位移数据计算的相对剪切模量。少

Palpation has been the clinical diagnostic modality to detect the changes in soft tissue elasticity, because the elasticity is usually related to some abnormal, pathological process. The goal of this study is to characterize tissue elasticity based on ultrasonic measurement of internal tissue deformation and displacement when the primary cardiac pulsation or the external mechanical force is applied to the soft tissue. A variational formulation is presented for the determination of the elasticity parameter of an isotropic, inhomogeneous, incompressible biological soft tissue, subject to external mechanical forces. Given a knowledge of the displacements throughout the tissue. A finite-element based model for static deformation is proposed for solving the distribution of the relative shear or Young's modulus of the tissue. The feasibility of the proposed method is demonstrated using the simulated deformation data of the simple three-dimensional inclusion problem. The results show that the … More relative shear modulus may be reconstructed from the displacement data measured locally in the region of interest within an isotropic, incompressible medium, and that the relative shear modulus can be recovered to some degree of accuracy from only 2-dimensional displacement data.Experiments on tissue mimicking phantoms were done. Mesurements are performed using real-time ultrasound and the sequences of RF echo signal returned from tissue ware digitized to estimate local tissue displacement. The 2-dimensional distribution of internal displacement was estimated using the spatio-temporal derivative of RF echo envelope signals, from which components of internal strain tensor were computed. Experimental results indicate that 2-dimensional fields of components of displacement can be estimated with the spatial resolution of 5mmx5mm. The distribution of the relative shear modulus based on displacement images was reconstructed. The elasticity of soft tissue can be characterized as the relative shear modulus computed from the local displacement data observed in the received RF echo signals. Less