基于改进相干因子的延时乘累加平面波超声成像

针对超声回波信号高相关性特性，提出一种基于改进相干因子的延时乘累加(pCF-DMAS)波束形成算法并应用至平面波超声成像.该算法通过增强相干因子的相干性来计算回波信号的权值，然后进行乘累加运算.通过使用Field II进行超声点目标和囊肿目标的仿真实验，对成像结果进行分析验证了算法的有效性.仿真结果表明，算法具有优秀的横向分辨率，在p取0.7时具有所有对比算法中的最高对比度.综合点目标和囊肿目标的成像效果，给出算法的最优p值0.3.相比延时叠加和延时乘累加波束形成算法，所提算法的图像对比度CR分别提高了12.559，9.602dB.

Plane Wave Ultrasonic Imaging Based on Improved Coherence Factor Delay Multiplication and Sum

Aiming at the high correlation characteristics of ultrasound echo signals， a delay multiplication and sum beamforming algorithm based on improved coherence factor(pCF-DMAS)is proposed and applied to plane wave ultrasound imaging. The algorithm calculates the weight of the echo signal by enhancing the coherence of the coherence factor， and then performs multiplication and sum operations. By using Field II to perform simulation experiments on ultrasound point targets and cyst targets， the imaging results are analyzed to verify the effectiveness of the algorithm. The simulation results show that the algorithm has excellent laterally resolution， and has the highest contrast when p is 0.7. With the imaging effects of point targets and cyst targets considered， the optimal p value of the algorithm is proposed to be 0.3. Compared with the delay stacking and delay multiplication and sum beamforming algorithms， the CR of the image is increased by 12.559， 9.602dB， respectively.