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组织振动信号的提取是剪切波频散超声振动成像技术(SDUV)方法中的重要步骤.目前,SDUV方法中有两种常用的组织振动信号提取算法,正交解调法(QDM)和互功率谱法(CSM),但是未见比较这两种算法提取质量差异的相关研究.因此,构造了不同信噪比(SNRU)的参数化仿真超声回波信号模型,分别使用QDM和CSM从超声回波信号中提取组织振动信号,比较了两种方法的提取效果与计算效率.实验结果表明,当SNRU≥35 d B,两种算法在相同信噪比下提取出的信号所分离出的振动相位结果相近,标准差均小于1°,对于剪切波波速的计算结果没有太大影响.CSM的计算效率低于QDM的计算效率.因此,当SNRU<35 d B,为了减小振动信号初始相位的提取误差,应该使用CSM提取组织的振动信号.当SNRU≥35 d B,应该选择QDM提取组织的振动信号,以减少信号处理时间.本研究的发现有助于提高SDUV方法的检测效率.
Tissue vibration signal extraction is an important step in shear wave dispersion ultrasonic vibration imaging (SDUV) method.At present, there are two commonly used algorithms for tissue vibration signal extraction in SDUV, such as quadrature demodulation (QDM) Power spectral method (CSM), but there is no correlation between these two algorithms to extract the quality difference.Therefore, a parametric simulation ultrasonic echo signal model with different signal-to-noise ratio (SNRU) is constructed, Echo signal extracted tissue vibration signal, compared the two methods of extraction efficiency and computational efficiency.The experimental results show that when the SNRU ≥ 35 d B, the two algorithms in the same signal-to-noise ratio of the signal extracted under the vibration The phase results are similar and the standard deviations are both less than 1 °, which is not much affected by the shear wave velocity calculation.The computational efficiency of CSM is lower than that of QDM.So, when SNRU <35 d B, in order to reduce the initial vibration signal CSM should be used to extract tissue vibration signal.When SNRU≥35 d B, QDM should be selected to extract the tissue vibration signal to reduce the signal processing time.The findings of this study will help to improve the detection efficiency of SDUV method.