Robust estimation of time-of-flight shear wave speed using a radon sum transformation.
Robust estimation of time-of-flight shear wave speed using a radon sum transformation.
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DOI：
10.1109/tuffc.2010.1740
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发表时间：
2010-12
期刊：
影响因子：
--
通讯作者：
Nightingale KR
中科院分区：
文献类型：
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作者：
Rouze NC;Wang MH;Palmeri ML;Nightingale KR
飞行时间方法允许根据组织中脉冲激励后的超声波跟踪位移来定量测量剪切波速度 (SWS)。然而，由于存在由生理运动或空间不均匀性等来源产生的总体异常数据，因此将这些方法应用于体内数据具有挑战性。本文描述了一种估计 SWS 的新方法，该方法考虑轨迹的解空间并使用表征沿整个轨迹的波浪运动的度量来评估每个轨迹。这里使用的度量是通过对沿着轨迹的位移数据求和来找到的，就像计算 Radon 变换中的投影数据一样。该算法使用在校准模型和体内人类肝脏中获取的数据进行评估。使用 Wang 等人描述的随机样本一致性 (RANSAC) 算法将结果与 SWS 估计值进行比较。氡气总和与 RANSAC SWS 估计之间存在良好的一致性，体模数据的相关系数大于 0.99，体内肝脏数据的相关系数大于 0.91。 Radon 和变换适合在需要实时反馈的情况下使用，并且对于异常数据而言与 RANSAC 算法相比具有相当的鲁棒性。
Time-of-flight methods allow quantitative measurement of shear wave speed (SWS) from ultrasonically tracked displacements following impulsive excitation in tissue. However, application of these methods to in vivo data is challenging due to the presence of gross outlier data resulting from sources such as physiological motion or spatial inhomogeneities. This paper describes a new method for estimating SWS by considering a solution space of trajectories and evaluating each trajectory using a metric that characterizes wave motion along the entire trajectory. The metric used here is found by summing displacement data along the trajectory as in the calculation of projection data in the Radon transformation. The algorithm is evaluated using data acquired in calibrated phantoms and in vivo human liver. Results are compared to SWS estimates using a random sample consensus (RANSAC) algorithm described by Wang, et al. Good agreement is found between the Radon sum and RANSAC SWS estimates with a correlation coefficient of greater than 0.99 for phantom data and 0.91 for in vivo liver data. The Radon sum transformation is suitable for use in situations requiring realtime feedback and is comparably robust to the RANSAC algorithm with respect to outlier data.