Validation of differences in backscatter coefficients among four ultrasound scanners with different beamforming methods
Validation of differences in backscatter coefficients among four ultrasound scanners with different beamforming methods
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DOI：
10.1007/s10396-019-00984-w
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发表时间：
2019-11-03
影响因子：
1.8
通讯作者：
Yamaguchi, Tadashi
中科院分区：
文献类型：
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作者：
Omura, Masaaki;Hasegawa, Hideyuki;Yamaguchi, Tadashi
目的 后向散射系数 (BSC) 表示材料的绝对散射特性，与临床医生和系统设置无关。我们的研究证实，用于生物组织定量超声分析的扫描仪、换能器和波束形成方法之间的 BSC 有所不同。方法对四个模拟组织的均质模型进行测量，其中包含平均直径为 20 和 30 μm 的球形散射体，浓度分别为 0.5 和 2.0 wt%。使用具有两个单元件换能器和五个线性高频或低频探头的超声波扫描仪对不同系统中的 BSC 进行比较。波束形成方法是使用聚焦成像（FI）的逐行形成和使用平面波成像（PWI）的平行波束形成。通过参考体模方法计算每个系统的BSC。对 Faran 模型计算出的理论 BSC 的平均偏差进行了分析，作为计算出的 BSC 的基准验证。结果在不同特性和波束形成方法的系统中计算的BSC与理论BSC很好地吻合。在所有情况下，平均偏差均低于 +/- 2.8 dB，并且在近似标准偏差内（最多 +/- 2.2 dB）。这些变化与之前的一项研究一致，其中采用 FI 波束成形的四种不同扫描仪之间的最大误差为 3.5 dB。结论 PWI 中的 BSC 与其他系统中的 BSC 以及 FI 波束形成中的 BSC 等效。这一结果表明使用 PWI 进行超高帧率 BSC 分析的可能性。
Purpose The backscatter coefficient (BSC) indicates the absolute scatterer property of a material, independently of clinicians and system settings. Our study verified that the BSC differed among the scanners, transducers, and beamforming methods used for quantitative ultrasound analyses of biological tissues. Methods Measurements were performed on four tissue-mimicking homogeneous phantoms containing spherical scatterers with mean diameters of 20 and 30 mu m prepared at concentrations of 0.5 and 2.0 wt%, respectively. The BSCs in the different systems were compared using ultrasound scanners with two single-element transducers and five linear high- or low-frequency probes. The beamforming methods were line-by-line formation using focused imaging (FI) and parallel beam formation using plane wave imaging (PWI). The BSC of each system was calculated by the reference phantom method. The mean deviation from the theoretical BSC computed by the Faran model was analyzed as the benchmark validation of the calculated BSC. Results The BSCs calculated in systems with different properties and beamforming methods well concurred with the theoretical BSC. The mean deviation was below +/- 2.8 dB on average, and within the approximate standard deviation (+/- 2.2 dB at most) in all cases. These variations agreed with a previous study in which the largest error among four different scanners with FI beamforming was 3.5 dB. Conclusion The BSC in PWI was equivalent to those in the other systems and to those of FI beamforming. This result indicates the possibility of ultra-high frame-rate BSC analysis using PWI.