子带技术在超声弹性成像中的应用研究

Ultrasound Strain Imaging Using Subband Processing

为了降低超声弹性成像噪声,提出将超声回波射频信号分割成几个子频带信号,然后分别对每个子频带信号进行应变估计得到子应变图像,最后将这些子应变图像叠加平均起来得到一个复合后的应变图像。先在理论上描述了该子带方法,然后在一个商用的超声弹性成像系统上,在一个仿真人体组织的弹性成像模型上测试和验证该方法的有效性,实验结果表明该子带方法可以提高应变图像质量,弹性信噪比提高了18%左右,对比噪声比提高了42%左右。

The subband processing was applied to ultrasound strain imaging to reduce strain noise.The echo radio frequency signal was separated into several frequency bands by subband filters.The strains of each subband were estimated and then all sub strain images were averaged to produce a compounded strain image.This approach was tested in a commercial strain imaging system by scanning a tissue-mimicking phantom.The experimental results demonstrated that the elastographic signal-to-noise ratio and elastographic contrast-to-noise ratio of strain image can be increased up to 18% and 42% by using subband processing,respectively.