Rapid tracking of small displacements with ultrasound
Rapid tracking of small displacements with ultrasound
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DOI：
10.1109/tuffc.2006.1642509
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发表时间：
2006-06-01
影响因子：
3.6
通讯作者：
Trahey, Gregg E.
中科院分区：
文献类型：
--
作者：
Pinton, Gianmarco F.;Dahl, Jeremy J.;Trahey, Gregg E.
时间延迟估计，如归一化互相关和相移估计，形成弹性成像，血流测量和声辐射力脉冲（ARFI）成像的计算基础。本文探讨了这些算法的小位移（小于一半的超声波脉冲波长）的性能。噪声，带宽，稳态回波，内核大小，下采样，插值和正交解调的时间延迟估计的准确性的影响进行测量的偏差和抖动。特别注意的是位移测量的精度和分辨率和算法的计算效率。在大多数情况下，Loupas的二维（2-D）自相关器的性能与黄金标准归一化互相关一样好。然而，Loupas算法的计算时间明显更快，并且特别适合对超声扫描仪中最常用的信号数据格式进行操作。这些结果被用来实现一个实时ARFI成像系统，使用商业超声扫描仪和计算机集群。在离体肝脏消融研究中检查用算法处理的图像。
Time-delay estimators, such as normalized cross correlation and phase-shift estimation, form the computational basis for elastography, blood flow measurements, and acoustic radiation force impulse (ARFI) imaging. This paper examines the performance of these algorithms for small displacements (less than half the ultrasound pulse wavelength). The effects of noise, bandwidth, stationary echoes, kernel size, downsampling, interpolation, and quadrature demodulation on the accuracy of the time delay estimates are measured in terms of bias and jitter. Particular attention is given to the accuracy and resolution of the displacement measurements and to the computational efficiency of the algorithms. In most cases, Loupas' two-dimensional (2-D) autocorrelator performs as well as the gold standard, normalized cross correlation. However, Loupas' algorithm's calculation time is significantly faster, and it is particularly suited to operate on the signal data format most commonly used in ultrasound scanners. These results are used to implement a real-time ARFI imaging system using a commercial ultrasound scanner and a computer cluster. Images processed with the algorithms are examined in an ex vivo liver ablation study.