Correlation of ultrasound speckle pattern and arrival time errors in shear wave elastography
Correlation of ultrasound speckle pattern and arrival time errors in shear wave elastography
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DOI：
10.1121/1.4830636
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发表时间：
2013-12
影响因子：
2.4
通讯作者：
S. McAleavey
中科院分区：
文献类型：
--
作者：
S. McAleavey
散斑是由相干照明和对来自许多次可分辨散射体的回波的相敏检测产生的。SPECKLE提供了一种纹理，允许对组织运动进行超声波跟踪，从而实现了多种类型的超声弹性成像。一个复杂的问题是，散斑的存在会导致传播中的剪切波的视相位或到达时间发生移位。证明了横波到达时间与静止发射光束和扫描接收光束测量的散斑图样之间的相关性。用发射f数为2~4、接收f数为2~8来跟踪模拟的声辐射力作用下产生的瞬时横波。横波到达时间误差与横扫接收散斑的横向一阶矩与横波速度之间存在很强的相关关系(r~0.6)。这些到达时间误差对横波的幅度(在−20到20μm范围内)和传播方向相对不敏感；例如，−20和+20μm横波的到达时间相差总到达时间误差的10%。讨论了剪切波弹性成像中斑点噪声的抑制方法。
Speckle results from coherent illumination and phase-sensitive detection of echoes from many sub-resolvable scatterers. Speckle provides a texture that allows ultrasonic tracking of tissue motion, which in turn enables the many varieties of ultrasound elastography. A complication is that the presence of speckle can induce a shift in the apparent phase or arrival time of a propagating shear wave. The correlation between shear wave arrival time and the speckle pattern measured with a stationary transmit beam and swept receive beams is demonstrated. Simulated transient shear waves generated in response to acoustic radiation force are tracked with transmit f-numbers of 2 to 4 and receive f-numbers of 2 to 8. The shear wave arrival time error and the lateral first moment of the swept-receive speckle pattern scaled by the shear wave speed are shown to be strongly, though not perfectly, correlated (r ~0.6). These arrival time errors are comparatively insensitive to the amplitude (over a range of −20 to 20 μm) and direction of propagation of the shear wave; e.g., arrival times for −20 and + 20 μm shear waves differed by <10% of the total arrival time error. Approaches for the suppression of speckle noise in shear wave elastography are discussed.