Normal & Shear Strain Imaging From Angled US Acquisition

描述(由申请人提供)： 目前的弹性成像只成像应变张量的轴向分量，而基本上忽略了横向和高程应变张量分量。在没有侧向分量和高程分量的情况下，其他重要的弹性参数，如剪切应变和泊松系数，将无法成像。此外，如果所有的法向应变张量和剪切应变张量都可用，那么从应变数据重建杨氏模数的努力将大大提高。在这项研究中，我们提出了一种新的方法来估计超声弹性成像中轴、侧和垂直方向的位移和应变。该方法使用由线阵换能器获取的沿多个角度超声波束方向估计的组织位移分量。然后，除了泊松比信息外，还根据轴向和横向位移信息计算法向和剪切张量的应变弹性图。 该研究计划为一种最先进的扫描仪开发和优化这种方法，使用模拟来评估采集率、角度和数据精度之间的权衡。这些技术的实施将在西门子Antares扫描仪上进行，利用新开发的超声研究接口来促进角度波束数据的采集和控制。使用弹性模版进行的测试将产生性能基准。还将开发两种新的体模类型，以评估获取这些图像中预期的基本信息的能力。最后，切除的组织样本将被成像以评估获得的新的弹性信息。 该方法的临床应用将用于区分乳房和甲状腺的良恶性肿块。在这两个部位，当组织被压缩时，许多良性肿块被认为发生了侧方滑移，而恶性肿块似乎没有滑移。拟议的横向和剪切应变图像预计将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.