弹性成像中组织横向位移引起的去相关效应的估计与降低

Estimation and reduction of decorrelation effect due to tissue lateral displacement in elastography.

作者信息

Bai Jing, Ding Chuxiong, Luo Jianwen, He Ping

机构信息

Institute of Biomedical Engineering, Department of Electrical Engineering, The School of Life Science and Engineering, Tsinghua University, Beijing, China.

出版信息

IEEE Trans Ultrason Ferroelectr Freq Control. 2002 May;49(5):541-9. doi: 10.1109/tuffc.2002.1002452.

DOI:10.1109/tuffc.2002.1002452

PMID:12046929

Abstract

In cross-correlation based elastography, the quality of the strain image is degraded by the distortion of echo waveforms due to tissue axial and lateral displacement. To study the effects of tissue lateral displacement on echo decorrelation, a tissue axial stretching model is developed and a concept called correlation signal-to-noise ratio (CSNR) is introduced to quantify the decorrelation effect due to tissue lateral displacement. A computer simulation based on the tissue stretching model is carried out to study the influence of several important elastographic parameters on echo decorrelation due to tissue lateral displacement. Finally, guided by the CSNR concept, a 2-dimensional (D) spatial comprehensive cross-correlation method is proposed to reduce the decorrelation noise. Results indicate that CSNR can be used as a quality indicator of elastography and the 2-D spatial comprehensive cross-correlation method can effectively reduce the decorrelation noise while slightly decreasing the lateral resolution of the strain image.

摘要

在基于互相关的弹性成像中，由于组织的轴向和横向位移导致回波波形失真，从而使应变图像的质量下降。为了研究组织横向位移对回波去相关的影响，建立了一个组织轴向拉伸模型，并引入了相关信噪比（CSNR）的概念来量化由于组织横向位移引起的去相关效应。基于该组织拉伸模型进行了计算机模拟，以研究几个重要的弹性成像参数对由于组织横向位移引起的回波去相关的影响。最后，在CSNR概念的指导下，提出了一种二维（2-D）空间综合互相关方法来降低去相关噪声。结果表明，CSNR可以用作弹性成像的质量指标，并且二维空间综合互相关方法可以有效降低去相关噪声，同时应变图像的横向分辨率略有下降。