In ultrasound elastography, plane-wave acquisitions and angular displacement compounding (ADC) are often used and combined to allow high frame rates and to improve accuracy of lateral displacement estimates, respectively. This study investigates the performance of displacement and strain estimation for ADC as a function of; the main-to-grating-lobe-amplitude ratio which decreases as a function of steering angle; plane-wave acquisition and Delay-and-Sum (DaS)-related parameters; and grating-lobe filter cut-off frequency. Three experiments were conducted with a block phantom to test ADC performance for displacement fields of varying complexity: a lateral transducer shift, phantom rotation and phantom deformation. Experiments were repeated for four linear array transducers (pitch-to-lambda ratios between 0.6 and 1.4). Best ADC performance was found for steering angles that resulted in a theoretically derived main-to-grating-lobe-amplitude ratio of 1.7 dB for pure lateral translation and 6 dB for predominately lateral strain or rotation. Temporal filtering to reduce grating lobe signal or shifting of the receive aperture to receive angles below or above the optimal angle, as dictated by the main-to-grating-lobe-amplitude ratio, did not improve results. The accuracy of lateral displacement and strain estimates was improved by apodization in transmission and a dedicated F-number in DaS (0.75) allowing incidence angles within ± 33° in the active aperture. ADC with the optimized settings as found in this study improves the accuracy of displacements and strain estimates up to 80.7% compared to non-ADC. Compared to ADC settings described in current literature, our optimization improved the accuracy by 11.9% to 75.3% for lateral displacement and strain, and by 89.3% to 96.2% for rotation. The accuracy of ADC in rotation seemed to depend highly on plane-wave and DaS-related parameters which may explain the major improvement compared to settings in current literature. The overall improvement by optimized ADC was statistically significant compared to non-ADC (p = 0.003) and literature (p = 0.002).

中文翻译：

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使用平面波超声优化角位移复合中的传输和重建参数。

在超声弹性成像中，经常使用平面波采集和角位移复合（ADC）并进行组合，以分别实现高帧频和提高横向位移估计的准确性。这项研究调查了ADC的位移和应变估算性能与的关系。主光栅波瓣振幅比随转向角的变化而减小；平面波采集和与延迟与和（DaS）相关的参数；和光栅瓣滤波器的截止频率。使用块体模进行了三个实验，以测试复杂度各不相同的位移场的ADC性能：横向换能器移位，体模旋转和体模变形。重复了四个线性阵列换能器的实验（螺距与拉姆达比在0.6和1.4之间）。对于转向角，发现了最佳的ADC性能，这导致理论推导的主-光栅波瓣-振幅比对于纯横向平移为1.7 dB，对于主要横向应变或旋转为6 dB。由主波瓣到波瓣振幅比所决定的，用于减小光栅波瓣信号的时间滤波或接收孔径的移动，以使接收角度低于或高于最佳角度，并不能改善结果。透射变迹和DaS中的专用F值（0.75）改善了横向位移和应变估计的准确性，允许F值在有源光圈中的入射角在±33°之内。与非ADC相比，本研究中具有优化设置的ADC将位移和应变估计的精度提高了80.7％。与当前文献中描述的ADC设置相比，我们的优化使横向位移和应变的精度提高了11.9％至75.3％，旋转的精度提高了89.3％至96.2％。ADC旋转的精度似乎很大程度上取决于平面波和与DaS相关的参数，这可能解释了与当前文献中的设置相比的重大改进。与非ADC（p = 0.003）和文献（p = 0.002）相比，优化ADC的总体改进在统计学上具有显着意义。