Department of Physics, University of Kuopio, 70211Kuopio, Finland.
IEEE Trans Biomed Eng. 2010 Jan;57(1):185-93. doi: 10.1109/TBME.2009.2033465. Epub 2009 Oct 9.
In this paper, a computational model for localized harmonic motion (LHM) imaging-based monitoring of high-intensity focused ultrasound surgery (FUS) is presented. The LHM technique is based on a focused, time-varying ultrasound radiation force excitation, which induces local oscillatory motions at the focal region. These vibrations are tracked, using pulse-echo imaging, and then, used to estimate the mechanical properties of the sonication region. LHM is feasible for FUS monitoring because changes in the material properties during the coagulation process affect the measured displacements. The presented model includes separate models to simulate acoustic sonication fields, sonication-induced temperature elevation and mechanical motion, and pulse-echo imaging of the induced motions. These 3-D simulation models are based on Rayleigh-Sommerfield integral, finite element, and spatial impulse response methods. Simulated-tissue temperature elevation and mechanical motion were compared with previously published in vivo measurements. Finally, the simulation model was used to simulate coagulation and LHM monitoring, as would occur with multiple, neighbouring sonication locations covering a large tumor.
本文提出了一种基于局部谐波运动（LHM）成像的高强度聚焦超声（FUS）手术监测的计算模型。LHM 技术基于聚焦、时变的超声辐射力激励，在焦点区域诱导局部振荡运动。这些振动通过脉冲回波成像进行跟踪，然后用于估计声处理区域的机械特性。LHM 适用于 FUS 监测，因为在凝固过程中材料性质的变化会影响测量的位移。所提出的模型包括单独的模型来模拟声处理场、声处理引起的温度升高和机械运动，以及诱导运动的脉冲回波成像。这些 3D 仿真模型基于瑞利-索末菲积分、有限元法和空间脉冲响应方法。模拟组织温度升高和机械运动与之前发表的体内测量结果进行了比较。最后，该仿真模型用于模拟凝固和 LHM 监测，这种情况会发生在多个相邻的声处理位置覆盖一个大肿瘤的情况下。
