Angular coherence in ultrasound imaging: Theory and applications
Angular coherence in ultrasound imaging: Theory and applications
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DOI：
10.1121/1.4976960
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发表时间：
2017-03-01
影响因子：
2.4
通讯作者：
Dahl, Jeremy J.
中科院分区：
文献类型：
--
作者：
Li, You Leo;Dahl, Jeremy J.
平面波以多个发射角度发射以用于合成发射孔径（或相干复合）的普及已经产生了超声成像的许多适应和新发展。然而，具有以不同角度发射的平面波的后向散射信号的相干特性是未知的，并且可能影响这些技术的子集。为了提供分析此类信号相干特性的框架，本文介绍了医学超声成像中的角相干理论。理论表明，这种信号的相关函数与接收孔径函数的自相关函数形成傅里叶变换对。这个结论可以看作是货车Cittert Zernike定理的推广形式。理论验证与仿真和实验结果获得的斑点目标。基于后向散射波的角相干性，提出了一种新的短滞后角相干波束形成器，并与现有的基于空间相干性的波束形成器进行了比较。最后给出了该理论在相位估计和声速估计中的应用。(C)2017年美国声学学会。
The popularity of plane-wave transmits at multiple transmit angles for synthetic transmit aperture (or coherent compounding) has spawned a number of adaptations and new developments of ultrasonic imaging. However, the coherence properties of backscattered signals with plane-wave transmits at different angles are unknown and may impact a subset of these techniques. To provide a framework for the analysis of the coherence properties of such signals, this article introduces the angular coherence theory in medical ultrasound imaging. The theory indicates that the correlation function of such signals forms a Fourier transform pair with autocorrelation function of the receive aperture function. This conclusion can be considered as an extended form of the van Cittert Zernike theorem. The theory is validated with simulation and experimental results obtained on speckle targets. On the basis of the angular coherence of the backscattered wave, a new short-lag angular coherence beamformer is proposed and compared with an existing spatial-coherence-based beamformer. An application of the theory in phase shift estimation and speed of sound estimation is also presented. (C) 2017 Acoustical Society of America.