Quantitative Compression Optical Coherence Elastography as an Inverse Elasticity Problem
Quantitative Compression Optical Coherence Elastography as an Inverse Elasticity Problem
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DOI：
10.1109/jstqe.2015.2512597
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发表时间：
2016-05-01
影响因子：
4.9
通讯作者：
Oberai, Assad A.
中科院分区：
文献类型：
--
作者：
Dong, Li;Wijesinghe, Philip;Oberai, Assad A.
定量弹性成像旨在检索组织弹性模量的空间图。与通常在压缩弹性成像中成像的应变不同，弹性模量是组织的固有特性，因此，这种方法重建的图像在很大程度上与操作员和系统无关，从而实现客观、纵向和多部位诊断。最近，新的定量弹性成像方法的压缩弹性成像已经开发出来。这些方法使用具有已知机械特性的校准层来感测组织表面处的应力，该应力与应变相结合，用于通过假设应力场中的均匀性来估计组织的弹性模量。然而，这一假设是违反机械异质性样品。我们提出了一个更一般的方法来定量弹性成像，克服了这一限制，通过一个有效的迭代解的逆弹性问题，使用伴随弹性方程。我们提出了线弹性，各向同性和不可压缩固体的解决方案，但是，这种方法可以用于更复杂的力学模型。我们检索的剪切模量的空间分布的组织模拟体模和组织样本。这是第一次，据我们所知，逆弹性问题的迭代求解已实施实验获得的压缩光学相干弹性成像数据。
Quantitative elasticity imaging seeks to retrieve spatial maps of elastic moduli of tissue. Unlike strain, which is commonly imaged in compression elastography, elastic moduli are intrinsic properties of tissue, and therefore, this approach reconstructs images that are largely operator and system independent, enabling objective, longitudinal, and multisite diagnoses. Recently, novel quantitative elasticity imaging approaches to compression elastography have been developed. These methods use a calibration layer with known mechanical properties to sense the stress at the tissue surface, which combined with strain, is used to estimate the tissue's elastic moduli by assuming homogeneity in the stress field. However, this assumption is violated in mechanically heterogeneous samples. We present a more general approach to quantitative elasticity imaging that overcomes this limitation through an efficient iterative solution of the inverse elasticity problem using adjoint elasticity equations. We present solutions for linear elastic, isotropic, and incompressible solids; however, this method can be employed for more complex mechanical models. We retrieve the spatial distribution of shear modulus for a tissue-simulating phantom and a tissue sample. This is the first time, to our knowledge, that the iterative solution of the inverse elasticity problem has been implemented on experimentally acquired compression optical coherence elastography data.