Normal & Shear Strain Imaging From Angled US Acquisition

描述（由申请人提供）： 目前的弹性成像实践仅对应变张量的轴向分量进行成像，而横向和纵向应变张量分量基本上被忽略。在没有横向和高程分量的情况下，其他重要的弹性参数（例如剪切应变和泊松）不会被成像。此外，如果所有法向应变张量和剪切应变张量均可用，则根据应变数据重建杨氏模量的工作将得到显着改善。在这项研究中，我们提出了一种估计超声弹性成像中轴向、横向和高度方向的位移和应变的新方法。该方法使用沿用线性阵列换能器获取的多个角度超声波束方向估计的组织位移分量。然后，除了泊松比信息之外，还可以根据轴向和横向位移信息计算法向张量和剪切张量的应变弹性图。 该研究计划为最先进的扫描仪开发和优化了这种方法，使用模拟来评估采集速率、角度和数据精度之间的权衡。该技术将在西门子 Antares 扫描仪上实施，利用新开发的超声研究接口来促进角波束数据采集和控制。使用弹性成像模型进行的测试将产生性能基准。还将开发两种新的模型类型，以评估导出这些图像中预期的基本信息的能力。最后，将对切除的组织样本进行成像，以评估获得的新弹性信息。 该方法的临床应用是区分乳房和甲状腺中的恶性肿块和良性肿块。在这两个部位，当组织受压时，许多良性肿块被认为会发生横向滑移，而恶性肿块似乎不存在滑移。预计所提出的横向和剪切应变图像对这种现象特别敏感。

DESCRIPTION (provided by applicant): The current practice of elastography, images only the axial component of the strain tensor, while the lateral and elevational strain tensor components are basically disregarded. In the absence of lateral and elevational components, other important elastic parameters such as shear strains and Poisson's are not imaged. Moreover, efforts at reconstruction of the Young's modulus from strain data would be significantly improved if all the normal and shear strain tensors are available. In this research, we propose a novel method of estimating displacements and strains in axial, lateral and elevational directions in ultrasound elastography imaging. The method uses tissue displacement components estimated along multiple angular ultrasound beam directions acquired with linear array transducers. Strain elastograms of normal and shear tensors are then calculated from the axial and lateral displacement information in addition to Poisson's ratio information. The research plan develops and optimizes this method for a state-of-the-art scanner using simulations to evaluate tradeoffs between acquisition rate, angles and data accuracy. Implementation of the techniques will be on the Siemens Antares scanner, capitalizing on a newly developed ultrasound research interface to facilitate angular beam data acquisition and control. Tests using elastography phantoms will yield performance benchmarks. Two new phantom types will also be developed to evaluate the ability to derive the fundamental information expected in these images. Finally, excised tissue samples will be imaged to evaluate the new elasticity information obtained. Clinical applications where the methodology will be directed are in differentiating malignant from benign masses in the breast and thyroid. In both sites lateral slippage is believed to occur in many benign masses when the tissue is compressed, while slippage appears to be absent with malignant masses. The proposed lateral and shear strain images are expected to be particularly sensitive to such phenomena.