互相关自适应加权的医学超声成像算法研究

根据超声成像系统的超声回波信号互相关性,提出互相关自适应加权超声成像算法.该算法根据散射点回波信号之间的空间相关性设置加权系数,对不同位置的散射点进行自适应加权成像,从而降低了成像系统的旁瓣,抑制了相关性较差的噪声.通过Field II仿真的点目标和吸声斑目标处理结果表明该方法成像的横向和纵向分辨率高,成像速度快.相对于延时叠加(DAS)算法,该算法对散射点成像可提高对比度16 dB,对于吸声斑成像可提高对比度0.85 dB.最后采用完备数据集进行实验,结果表明该算法成像分辨率优于DAS算法,对比度提高了17 dB.

Medical ultrasound imaging based on cross-correlation adaptive weighting

According to the cross-correlation between the ultrasonic echo signals of ultrasonic imaging system, ultrasonic imaging algorithm based on cross-correlation adaptive weighting is introduced. This method determines the weight on the correlation between the echo signals of scatters at different positions, and then the adaptive weighted imaging is performed. The sidelobe and the noise which has the low correlation are suppressed. Simulations to points object and speckle object pattern using Field Ⅱ show that the method of imaging fast, and it can give a high horizontal and longitudinal resolution. Compared with delay and sum (DAS) algorithm, the contrast of the image to point object is increased by 16 dB. The contrast of the image to sound-absorbing speckle is increased by 0.85 dB. The results of experiments in which the complete data sets are used, show that the resolution is better than that of DAS algorithm and the contrast is increased by 17 dB.
Keywords： delay and sum cross-correlation adaptive weighting general coherence factor contrast