ESTIMATION AND IMAGING OF TISSUE ELASTICITY

在本项目资助期内，我们完成了以下工作。1.我们已经证明，它是可能的，以产生良好的客观质量的图像（弹性图）从幻影和组织在体内和体外使用稍微修改的商业超声扫描仪。2.研究表明，正常组织成分和肿瘤组织中存在可靠的弹性模量差;已经阐明了质量弹性图生产中涉及的机械、数学、统计、声学和信号处理问题的科学基础，并计算了性能上限。已经开发了许多新的工具来改进相关参数之间的权衡。在这个更新的应用程序中，我们的假设是，显着改善弹性图可以通过使用我们的知识，基本的弹性组织特性和弹性成像成像过程。 为了检验这一假设，我们提出了以下具体目标。目标1至3旨在进一步提高弹性图的客观质量，并从中获得额外的相关信息;目标4和5旨在增加我们对基本组织力学特性的理解，并研究成像中涉及的实际问题。目标1。研究软件、体模模型和组织中弹性成像纹理的理论和实践方面。将弹性纹理（模量和应变）与实际刚度纹理相关联。目标二。研究改善客观弹性成像参数的采集和信号处理策略。目标3。研究轴向和横向组织应变成像、组织泊松比以及正交方向运动弹性图校正所涉及的理论和实践问题。目标4。继续研究组织的基本弹性行为（Baylor）。目标5。发展非相干谱应变估计技术及其在噪声环境下弹性成像中的应用。

In the present funding period of this project, we have accomplished the following tasks. 1. We have demonstrated that it is possible to produce images (elastograms) of good objective quality from phantoms and tissue sin vivo and in vitro using a slightly modified commercial ultrasound scanner. 2. It has been demonstrated that reliable elastic modulus contrast exists in normal tissue component and in tumors; 3. The scientific foundations of the mechanical, mathematical, statistical, acoustical and signal processing issues involved in the production of quality elastograms have been elucidated and upper performance bounds have been calculated. Numerous new tools have been developed to improve the tradeoffs among the relevant parameters. In this renewal application, our hypothesis is that significant improvements to elastograms may be obtained by using our knowledge about basic elastic tissue properties and about the elastographic image formation process. In order to test this hypothesis, we propose the specific aims shown below. Aims 1 through 3 are designed to further improve on the objective quality of the elastograms and to derive additional relevant information from them; aims 4 and 5 strive to increase our understanding of basic tissue mechanical properties, and to investigate the practical issues involved in imaging them. Aim 1. Investigate the theoretical and practical aspects of elastographic texture in software, phantom models and tissues. Relate elastographic texture (modulus and strain) to actual stiffness texture. Aim 2. Investigate acquisition and signal processing strategies for improving objective elastographic image parameters. Aim 3. Investigate the theoretical and practical issues involved in the imaging of axial and lateral tissue strains, tissue Poisson's ratios, and in applying corrections of elastograms for motions in orthogonal directions. Aim 4. Continue to investigate the basic elastic behavior of tissues (Baylor subcontract). Aim 5. Develop an Incoherent Spectral Strain Estimation technique and its applications to elastography in noisy environments.