Zvietcovich Fernando, Singh Manmohan, Ambekar Yogeshwari S, Aglyamov Salavat R, Twa Michael D, Larin Kirill V
Department of Biomedical Engineering, University of Houston, Houston, TX 77204 USA.
Department of Mechanical Engineering, University of Houston, Houston, TX 77204 USA.
IEEE J Sel Top Quantum Electron. 2021 Jul-Aug;27(4). doi: 10.1109/jstqe.2020.3038633. Epub 2020 Nov 17.
In optical coherence elastography (OCE), air-pulse stimulation has been widely used to produce propagation of mechanical waves for elastic characterization of tissues. In this paper, we propose the use of spatial deformation spreading (SDS) on the surface of samples produced by air-pulse stimulation for the OCE of transverse isotropic tissues. Experiments in isotropic tissue-mimicking phantoms and anisotropic chicken tibialis muscle were conducted using a spectral-domain optical coherence tomography system synchronized with a confocal air-pulse stimulation. SDS measurements were compared with wave speeds values calculated at different propagation angles. We found an approximately linear relationship between shear wave speed and SDS in isotropic phantoms, which was confirmed with predictions made by the numerical integration of a wave propagation model. Experimental measurements in chicken muscle show a good agreement between SDS and surface wave speed taken along and across the axis of symmetry of the tissues, also called degree of anisotropy. In summary, these results demonstrated the capabilities of SDS produced by the air-pulse technique in measuring the shear elastic anisotropy of transverse isotropic tissues.
在光学相干弹性成像（OCE）中，空气脉冲刺激已被广泛用于产生机械波传播，以对组织进行弹性表征。在本文中，我们提出将空气脉冲刺激产生的样品表面空间变形扩展（SDS）用于横向各向同性组织的OCE。使用与共焦空气脉冲刺激同步的光谱域光学相干断层扫描系统，对各向同性组织模拟体模和各向异性鸡胫骨肌肉进行了实验。将SDS测量结果与在不同传播角度计算的波速值进行了比较。我们发现各向同性体模中剪切波速与SDS之间存在近似线性关系，这通过波传播模型的数值积分预测得到了证实。在鸡肌肉中的实验测量表明，SDS与沿组织对称轴以及横跨组织对称轴（也称为各向异性程度）测得的表面波速之间具有良好的一致性。总之，这些结果证明了空气脉冲技术产生的SDS在测量横向各向同性组织的剪切弹性各向异性方面的能力。
