中文摘要：

超声造影剂的定向输运在超声医学成像领域有着极为重要的意义，而声辐射力作用是实现该过程的关键，相比于高斯声束，准高斯声束是无源亥姆霍兹方程的精确解，可以使用标准波分解法简化计算。因此，本文研究了准高斯声束对超声造影剂的声辐射力作用。文章首先分析了准高斯声束与高斯声束之间的相关性；随后通过数值计算求得了准高斯声束对超声造影剂模型的声辐射力函数与无量纲频率之间的关系；最后，本文研究了不同造影剂气泡情况下的声辐射力。研究结果表明：声辐射力函数随无量纲频率变化将在不同位置出现共振峰，不同的波束宽度值将改变辐射力强度，但不改变共振峰的位置。相关结果可为利用声辐射力定向输运超声造影剂至靶向位置提供理论参考。

英文摘要：

Targeted transfer of ultrasound contrast agents has significant meanings in the field of ultrasoundbiomedical imaging. The application of acoustic radiation force is the key to achieve this. In comparison with aGaussian beam, a quasi-Gaussian beam satisfies the source-free Helmholtz equation and we could greatly simplifythe calculation under the premise of accuracy with the standard wave-decomposition method. Therefore,the acoustic radiation force of a quasi-Gaussian beam on ultrasound contrast agents is studied in this paper.We first compare the quasi-Gaussian beam with the Gaussian beam, and then compute the acoustic radiationforce function of a quasi-Gaussian beam on ultrasound contrast agents versus the dimensionless frequency. Wefinally investigate the acoustic radiation force on different ultrasound contrast agents. The research results showthat the acoustic radiation force function has resonant peaks at different values of dimensionless frequency.The width of the beam only changes the amplitude of the acoustic radiation force function, not the locationsof resonant peaks. This paper may provide important theoretical reference for targeted transfer of ultrasoundcontrast agents with acoustic radiation force.