深圳大学学报理工版

提出一种新的剪切波弹性成像方法,将2D SG(Savitzky-Golay)数字差分器用于剪切波计算中,使用二维曲面拟合来近似剪切波波前到达时刻,该方法相比传统的线性回归方法不易受异常数据影响,鲁棒性更强. 通过超声弹性仿体实验评估这两种方法,比较不同尺寸下的2D SG数字差分器和线性回归的剪切波弹性图. 结果表明,在图像的横向分辨率相同的情况下,本研究方法得到的剪切波弹性图像更平滑,噪声更小,且剪切波弹性图像的信噪比和对比度噪声均比传统方法要高,表明该方法能提高剪切波弹性图像的质量.

We propose a new shear wave elastography method based on the 2D Savitzky-Golay(SG)digital differentiator in the shear wave speed estimation. The 2D SG digital differentiator utilizes two dimensional surface fitting method to obtain the arrival time of shear wave's wave-front. In comparison with the linear regression method, the 2D SG digital differentiator is not only less affected by the outlier data but also more robust. Moreover, we use the ultrasound elastic phantom experiments to evaluate the two methods and compare the shear wave elastograms obtained by the two methods. The elastograms obtained by our proposed method are smoother and have lower noise than those of linear regression method, while the lateral resolutions of images are the same. In our phantom experiment, the shear wave elastograms for our new method have higher signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR). The research shows that the new proposed method effectively improves the quality of shear wave elastogram.

引言
1 实验设备
2 实验方法
3 实验结果
4 结语

图1 本实验所用弹性仿体<br/>Fig.1 (Color online)The elastic phantom used in the experiment

图1 本实验所用弹性仿体
Fig.1 (Color online)The elastic phantom used in the experiment

图2 剪切波在不同时刻的位置以及不同位置点的轴向运动速度随时间的变化<br/>Fig.2 (Color online)The positions of shear wave at different time and the tissue motion speed change with time at different positions

图2 剪切波在不同时刻的位置以及不同位置点的轴向运动速度随时间的变化
Fig.2 (Color online)The positions of shear wave at different time and the tissue motion speed change with time at different positions

图3 感兴趣区域内剪切波到达的时刻和不同长度的二维SG差分器和线性回归计算出的剪切波速度 <br/>Fig.3 (Color online)The shear wave arrival time in the interesting region and the shear wave speed obtained by 2D SG differentiator and linear regression with different lengths

图3 感兴趣区域内剪切波到达的时刻和不同长度的二维SG差分器和线性回归计算出的剪切波速度
Fig.3 (Color online)The shear wave arrival time in the interesting region and the shear wave speed obtained by 2D SG differentiator and linear regression with different lengths

图4 用不同长度的二维SG差分器和线性回归计算出的内含物中心处的剪切波速度分布
Fig.4 (Color online)The shear wave speed profile of inclusion obtained by 2D SG differentiator and linear regression

表1 不同差分长度下,二维SG差分器和线性回归计算出的剪切波速度图的信噪比和对比度噪声<br/>Table 1 The comparsion of CNR and SNR of shear wave elastogram obtained by 2D SG differentiator and linear regression

表1 不同差分长度下,二维SG差分器和线性回归计算出的剪切波速度图的信噪比和对比度噪声
Table 1 The comparsion of CNR and SNR of shear wave elastogram obtained by 2D SG differentiator and linear regression

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备注

引言

1 实验设备

2 实验方法

3 实验结果

4 结语

期刊信息

备注

引言

1 实验设备

2 实验方法

3 实验结果

4 结 语

期刊信息

4 结语