An analytical model of full-field displacement and strain induced by amplitude-modulated focused ultrasound in harmonic motion imaging.
An analytical model of full-field displacement and strain induced by amplitude-modulated focused ultrasound in harmonic motion imaging.
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DOI：
10.1088/1361-6560/abddd1
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发表时间：
2021-04-06
影响因子：
3.5
通讯作者：
Konofagou EE
中科院分区：
文献类型：
--
作者：
McGarry MDJ;Campo A;Payen T;Han Y;Konofagou EE
大多数疾病过程涉及受影响组织的微观结构的变化，这可以转化为相应组织机械特性的变化。简谐运动成像 (HMI) 是一种弹性成像技术，可通过检测由振荡声辐射力 (ARF) 产生的简谐运动场的组织响应来研究组织的机械参数。 HMI 已在肿瘤检测和表征以及消融过程监测中得到证实。在本研究中，演示了分析 HMI 模型，并将其与有限元模型 (FEM) 进行了比较，从而可以快速准确地计算均匀线弹性材料中任意位置的位移、应变和剪切波速度 (SWV)。对于 41940 个力体素，每次位移评估需要 0.22 秒，分析模型和 FEM 之间的平均绝对差异分别为 1.2% 的位移和 0.5% 的应变。收敛研究表明，如果力分辨率提高，位移和应变的平均差异可分别进一步减小至 1.0% 和 0.15%。根据 FEM 和分析模型计算，SWV 场的速度区域差异高达 0.57 m/s，平均绝对差异为 0.11±0.07 m/s，这主要是由于非反射 FEM 边界条件的缺陷。由于近场和中场效应，视在 SWV 与常用平面波近似的差异高达 1.2 m/s。具有夹杂物的模型的最大位移幅度在夹杂物半径为 10mm 时稳定在均质模型的 10% 以内，而最大应变反应更快，在夹杂物半径为 3mm 时稳定。总之，本文提出了一种用于 HMI 刚度估计的分析模型。分析模型比 FEM 具有优势，因为不需要计算全场位移来评估单个测量点的模型。这一优势加上计算速度，使得分析模型对于实时成像应用非常有用。然而，分析模型被发现对组织均匀性和无限维度具有限制性假设，而有限元方法显示出适用于可变几何形状和非均匀特性。
The majority of disease processes involves changes in the micro-structure of the affected tissue, which can translate to changes in the mechanical properties of the corresponding tissue. Harmonic motion imaging (HMI) is an elasticity imaging technique that allows the study of the mechanical parameters of tissue by detecting the tissue response by a harmonic motion field, which is generated by oscillatory acoustic radiation force (ARF). HMI has been demonstrated in tumor detection and characterization as well as monitoring of ablation procedures. In this study, an analytical HMI model is demonstrated and compared with a finite element model (FEM), allowing rapid and accurate computation of the displacement, strain, and shear wave velocity (SWV) at any location in a homogenous linear elastic material. Average absolute differences between the analytical model and the FEM were respectively 1.2 % for the displacements and 0.5 % for the strains for 41940 force voxels at 0.22 seconds per displacement evaluation. A convergence study showed that the average difference could be further decreased to 1.0 % and 0.15 % for the displacements and strains, respectively, if force resolution is increased. SWV fields, as calculated with the FEM and the analytical model, have regional differences in velocities up to 0.57 m/s with an average absolute difference of 0.11±0.07 m/s, primarily due to imperfections in the non-reflecting FEM boundary conditions. The apparent SWV differed from the commonly used plane-wave approximation by up to 1.2 m/s due to near and intermediate field effects. Maximum displacement amplitudes for a model with an inclusion stabilize within 10 % of the homogenous model at an inclusion radius of 10mm while the maximum strain reacts faster, stabilizing at an inclusion radius of 3 mm. In conclusion, an analytical model for HMI stiffness estimation is presented in this paper. The analytical model has advantages over FEM as the full-field displacements do not need to be calculated to evaluate the model at a single measurement point. This advantage, together with the computational speed, makes the analytical model useful for real-time imaging applications. However, the analytical model was found to have restrictive assumptions on tissue homogeneity and infinite dimensions, while the FEM approaches were shown adaptable to variable geometry and non-homogenous properties.
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影响因子：
2.9
作者：
Curiel, Laura;Chopra, Rajiv;Hynynen, Kullervo
通讯作者：
Hynynen, Kullervo
影响因子：
4.4
作者：
Glaser, Kevin J.;Manduca, Armando;Ehman, Richard L.
通讯作者：
Ehman, Richard L.
DOI：
10.1109/tuffc.2015.007113
发表时间：
2015-09
期刊：
IEEE transactions on ultrasonics, ferroelectrics, and frequency control
影响因子：
--
作者：
Chen H;Hou GY;Han Y;Payen T;Palermo CF;Olive KP;Konofagou EE
通讯作者：
Konofagou EE
DOI：
10.1073/pnas.96.12.6603
发表时间：
1999-06-08
影响因子：
11.1
作者：
Fatemi, M;Greenleaf, JF
通讯作者：
Greenleaf, JF
影响因子：
4
作者：
Catheline, S.;Souchon, R.;Chapelon, J. -Y.
通讯作者：
Chapelon, J. -Y.