On the estimation of backscatter coefficients using single-element focused transducers
On the estimation of backscatter coefficients using single-element focused transducers
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DOI：
10.1121/1.3557036
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发表时间：
2011-05-01
影响因子：
2.4
通讯作者：
Oelze, Michael L.
中科院分区：
文献类型：
--
作者：
Lavarello, Roberto J.;Ghoshal, Goutam;Oelze, Michael L.
基于后向散射系数（BSC）估计的定量超声（QUS）成像方法的最终目标是获得与系统无关的样本结构信息。在本研究中，使用相同的后向散射压力数据集比较和评估了三种BSC估计方法，以评估其一致性。BSC的估计值从两个幻影与嵌入的玻璃球，并与理论计算的BSC使用的尺寸分布估计，使用光学显微镜。玻璃球的有效散射体直径和浓度估计也从估计的BSC获得。一种估计方法需要在幅度上补偿超过一个数量级，以便产生与其他两种方法相当的BSC。所有的校准方法都引入了不同的频率依赖性效应，这可能会对实验BSC得出的QUS估计值的偏差产生明显的影响。虽然在大多数情况下，用所有三种方法获得的实验QUS估计值被观察到相差不到10%，但预计更大的差异取决于换能器的压力聚焦增益（与孔径半径的平方与波长和焦距的乘积的比率成比例）和估计中使用的ka范围。(C)2011年美国声学学会。[DOI 10.1121/1.3557036]
The ultimate goal of quantitative ultrasound (QUS) imaging methods based on backscatter coefficient (BSC) estimates is to obtain system-independent structural information about samples. In the current study, three BSC estimation methods were compared and evaluated using the same backscattered pressure datasets in order to assess their consistency. BSC estimates were obtained from two phantoms with embedded glass spheres and compared to theoretical BSCs calculated using size distributions estimated using optical microscopy. Effective scatterer diameter and concentration estimates of the glass spheres were also obtained from the estimated BSCs. One estimation method needed to be compensated by more than an order of magnitude in amplitude in order to produce BSCs comparable to the other two methods. All calibration methods introduced different frequency-dependent effects, which could have noticeable effects on the bias of QUS estimates derived from experimental BSCs. Although in most cases the experimental QUS estimates obtained with all three methods were observed to differ by less than 10%, larger differences are expected depending on both the pressure focusing gain of the transducer (proportional to the ratio of the square of the aperture radius to the product of the wavelength and focal length) and ka range used in the estimation. (C) 2011 Acoustical Society of America. [DOI: 10.1121/1.3557036]