Lopata Richard G P, Hansen Hendrik H G, Nillesen Maartje M, Thijssen Johan M, De Korte Chris L
Clinical Physics Laboratory-833, Department ofPediatrics, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
Ultrason Imaging. 2009 Jan;31(1):1-16. doi: 10.1177/016173460903100101.
In this study, the performances of one-dimensional and two-dimensional least-squares strain estimators (LSQSE) are compared. Furthermore, the effects of kernel size are examined using simulated raw frequency data of a widely-adapted hard lesion/soft tissue model. The performances of both methods are assessed in terms of root-mean-squared errors (RMSE), elastographic signal-to-noise ratio (SNRe) and contrast-to-noise ratio (CNRe). RMSE analysis revealed that the 2D LSQSE yields better results for phased array data, especially for larger insonification angles. Using a 2D LSQSE enabled the processing of unfiltered displacement data, in particular for the lateral/horizontal strain components. The SNRe and CNRe analysis showed an improvement in precision and almost no loss in contrast using 2D LSQSE. However, the RMSE images for different kernel sizes revealed that the optimal 2D kernel size depends on the region-of-interest and showed that the LSQ kernel size should be limited to avoid loss in resolution.
在本研究中，对一维和二维最小二乘应变估计器（LSQSE）的性能进行了比较。此外，使用广泛适用的硬病变/软组织模型的模拟原始频率数据研究了内核大小的影响。两种方法的性能根据均方根误差（RMSE）、弹性成像信噪比（SNRe）和对比噪声比（CNRe）进行评估。RMSE分析表明，二维LSQSE对相控阵数据产生更好的结果，特别是对于较大的声束入射角度。使用二维LSQSE能够处理未滤波的位移数据，特别是对于横向/水平应变分量。SNRe和CNRe分析表明，使用二维LSQSE时精度有所提高，且对比度几乎没有损失。然而，不同内核大小的RMSE图像显示，二维内核的最佳大小取决于感兴趣区域，并表明LSQ内核大小应加以限制以避免分辨率损失。
