University of Rochester, Department of Electrical and Computer Engineering, Rochester, New York, United States.
University of Rochester, The Institute of Optics, Rochester, New York, United States.
J Biomed Opt. 2017 Mar 1;22(3):35010. doi: 10.1117/1.JBO.22.3.035010.
We compare five optical coherence elastography techniques able to estimate the shear speed of waves generated by one and two sources of excitation. The first two techniques make use of one piezoelectric actuator in order to produce a continuous shear wave propagation or a tone-burst propagation (TBP) of 400 Hz over a gelatin tissue-mimicking phantom. The remaining techniques utilize a second actuator located on the opposite side of the region of interest in order to create three types of interference patterns: crawling waves, swept crawling waves, and standing waves, depending on the selection of the frequency difference between the two actuators. We evaluated accuracy, contrast to noise ratio, resolution, and acquisition time for each technique during experiments. Numerical simulations were also performed in order to support the experimental findings. Results suggest that in the presence of strong internal reflections, single source methods are more accurate and less variable when compared to the two-actuator methods. In particular, TBP reports the best performance with an accuracy error < 4.1 % . Finally, the TBP was tested in a fresh chicken tibialis anterior muscle with a localized thermally ablated lesion in order to evaluate its performance in biological tissue.
我们比较了五种能够估计由一个和两个激励源产生的波的剪切速度的光学相干弹性成像技术。前两种技术利用一个压电致动器来产生连续的剪切波传播或在明胶组织模拟体上传播 400 Hz 的声爆发（TBP）。其余的技术利用位于感兴趣区域的相对侧的第二个致动器来创建三种类型的干涉模式：爬行波、扫频爬行波和驻波，这取决于两个致动器之间的频率差的选择。我们在实验中评估了每种技术的准确性、与噪声比、分辨率和采集时间。还进行了数值模拟以支持实验结果。结果表明，在存在强内部反射的情况下，与两个致动器方法相比，单源方法更准确且变化更小。特别是 TBP 的准确性误差 < 4.1%，报告了最佳性能。最后，TBP 在新鲜的鸡胫骨前肌上进行了局部热消融损伤的测试，以评估其在生物组织中的性能。
