Analysis of mechanical contrast in optical coherence elastography
Analysis of mechanical contrast in optical coherence elastography
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DOI：
10.1117/1.jbo.18.12.121508
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发表时间：
2013-12-01
影响因子：
3.5
通讯作者：
Sampson, David D.
中科院分区：
文献类型：
--
作者：
Kennedy, Kelsey M.;Ford, Chris;Sampson, David D.
光学相干弹性成像(OCE)反映了组织微观结构的力学性质，在生物力学和临床医学的基础研究中具有潜在的应用价值。我们报告了OCE中对比度的第一次分析，包括评估OCE图像(弹性图)表示机械特性的准确性以及OCE对样本中机械对比度的敏感性。使用相敏压缩OCE，我们生成具有已知机械特性的模拟组织体模的弹性图，并识别样本力学和成像系统施加的对比度限制，包括信号处理参数。我们还使用有限元模型生成模拟弹性图，以便在没有成像系统噪声的情况下执行力学分析。在实验和模拟中，我们都说明了降低弹性图精度的伪影，这取决于样本几何形状、特征之间的弹性对比度和表面条件。我们在实验中展示了对弹性对比度为1.1：1的特征的敏感度，并根据我们的成像系统参数计算出对弹性对比度的理论最大敏感度为1.002：1。结果突出了压缩OCE在数十微米的空间分辨率下的微应变敏感度，表明它有可能检测到不同组织中弹性的微小变化。(C)2013年光学仪器工程师学会(SPIE)
Optical coherence elastography (OCE) maps the mechanical properties of tissue microstructure and has potential applications in both fundamental investigations of biomechanics and clinical medicine. We report the first analysis of contrast in OCE, including evaluation of the accuracy with which OCE images (elastograms) represent mechanical properties and the sensitivity of OCE to mechanical contrast within a sample. Using phase-sensitive compression OCE, we generate elastograms of tissue-mimicking phantoms with known mechanical properties and identify limitations on contrast imposed by sample mechanics and the imaging system, including signal-processing parameters. We also generate simulated elastograms using finite element models to perform mechanical analysis in the absence of imaging system noise. In both experiments and simulations, we illustrate artifacts that degrade elastogram accuracy, depending on sample geometry, elasticity contrast between features, and surface conditions. We experimentally demonstrate sensitivity to features with elasticity contrast as small as 1.1:1 and calculate, based on our imaging system parameters, a theoretical maximum sensitivity to elasticity contrast of 1.002:1. The results highlight the microstrain sensitivity of compression OCE, at a spatial resolution of tens of micrometers, suggesting its potential for the detection of minute changes in elasticity within heterogeneous tissue. (C) 2013 Society of Photo-Optical Instrumentation Engineers (SPIE)