高分辨率扇形阵列超声激发振动声成像研究

对扇阵换能器的振动声成像进行了研究.在相关振动声成像和扇阵换能器的理论基础上，经过推导修正并得到了精确的速度势函数.进一步计算并仿真了系统点扩散函数（point spread function, PSF），构造了组织模型，进行了成像仿真.最后分析了影响扇阵换能器系统分辨率的因素.研究结果表明：用扇阵换能器进行振动声成像可以获得很高的图像分辨率及对比度，在高强度聚焦超声（HIFU）治疗的热损伤检测等方面有重要的应用价值.分析指出通过提高换能器工作频率，减小几何焦距，增大口径可以提高系统的分辨率. 关键词： 振动声成像 扇形阵 点扩散函数

Study of vibro-acoustography with high spatial resolution based on sector array transducers

This study investigates the vibro-acoustography of sector array transducers. Based on the vibro-acoustography and basic sector-array field theory, a modified and accurate velocity potential function is obtained. We further calculated and simulated the point spread function （PSF） of the system, designed the phantom of tissue, and simulated the phantom imaging. In the end, the influencing factors on spatial resolution with sector array transducers are analyzed on the basis of the simulation results. The results reveal that high resolution and contrast can be achieved, and this imaging method is of great value in detecting thermal lesion after high intensity ultrasound surgery and so on. The resolution will be improved by increasing central frequency, reducing geometric focal distance, and using transducers with larger aperture size.