Microbubble behavior in an ultrasound field for high intensity focused ultrasound therapy enhancement.
Microbubble behavior in an ultrasound field for high intensity focused ultrasound therapy enhancement.
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DOI：
10.1121/1.4812880
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发表时间：
2013-08
期刊：
影响因子：
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通讯作者：
K. Okita;K. Sugiyama;S. Takagi;Yoichi Matsumto
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文献类型：
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作者：
K. Okita;K. Sugiyama;S. Takagi;Yoichi Matsumto
由于惯性空化而引起的加热的增强已经被集中以减少常规高强度聚焦超声（HIFU）治疗的长治疗时间。研究了周围组织的物理性质、初始空隙率和气泡的空间分布对微泡增强HIFU的影响。气泡动力学方程的基础上的Keller-Miksis方程，考虑到周围组织的弹性。采用欧拉-拉格朗日方法对混合相和气泡进行耦合，以考虑超声和气泡之间的相互作用。结果，靶周围的温度随着初始空隙率而增加。但是在10（-5）的高空隙率下，超声衰减太大而不能加热目标，并且加热区域移动到换能器侧。另一方面，周围介质的粘性和剪切弹性都降低了超声传播通过气泡混合物的衰减。数值结果表明，局部加热是由粘性或剪切弹性引起的，尽管它取决于压力幅值。此外，它被数值证实，微泡分布的本地化是重要的，以获得有效的局部加热。
The enhancement of heating due to inertial cavitation has been focused to reduce the long treatment time of conventional high-intensity focused ultrasound (HIFU) therapy. The influences of the physical properties of surrounding tissues, initial void fraction, and spatial distribution of bubbles on microbubble-enhanced HIFU are examined. A bubble dynamics equation based on the Keller-Miksis equation is employed in consideration of the elasticity of surrounding tissue. The mixture phase and bubbles are coupled by the Euler-Lagrange method to take into account the interaction between ultrasound and bubbles. As a result, the temperature around the target increases with the initial void fraction. But at the high void fraction of 10(-5), ultrasound is too attenuated to heat the target, and the heating region moves to the transducer side. On the other hand, both the viscosity and shear elasticity of the surrounding media reduce the attenuation of ultrasound propagation through the bubbly mixture. Numerical results show that localized heating is induced with increasing viscosity or shear elasticity, though it depends on the pressure amplitudes. In addition, it was numerically confirmed that the localization of the microbubble distribution is important to obtain efficient localized heating.