一种基于编码激励的超声弹性成像噪声抑制方法

Noise suppression method for ultrasound strain imaging based on coded excitation

超声弹性成像是利用生物组织弹性信息进行成像的影像学检测技术,但图像上严重的伪影噪声降低了其临床诊断价值。编码激励技术在提高超声回波信号的信噪比、增加探测深度等方面有显著效果,同时,超声空间复合方法利用帧间噪声解相关性可有效抑制伪影噪声。为此,在应用Chirp编码激励技术的基础上,结合接收端的基于滤波器的弹性成像空间复合去噪算法,进一步提高弹性图像质量;利用FieldⅡ仿真工具,以Chirp作为激励信号仿真并计算复合的弹性应变。实验结果表明,该方法能较强抑制弹性图像的伪影噪声,对比传统弹性成像系统,弹性图像的信噪比及对比度噪声比有明显的提升。

Ultrasound elastography is the technique of obtaining the tissue relative stiffness information. However, artifact noise often corrupts the elastography image quality severely, which decreases the diagnostic value of image~ Coded excitation tech- nique has outstanding features of increasing signal＇ s SNR and the detection depth, meanwhile, ultrasound spatial-compounding method can suppress artifact noise effectively using the decorrelation feature between frames. This paper used filter based re- ceive-side spatial compounding method based on Chirp-coded excitation technique, gaining much better quality for elastogra- phy. By using the Field I1 simulation tools with Chirp-coded excitation signal, experimental results show that artifact noise is suppressed obviously with a measurable improvement in SNRe （elastographic signal-to-noise ratio） and CNRe （elastographic contrast-to-noise ratio） in strain images corresponding to the conventional system.