ACOUSTIC NONLINEARITY FOR TISSUE CHARACTERIZATION

这项建议的目标是确定1)非线性程度 2)如何利用这些信息来获得 可靠的超声图像，最后是哪种类型的信息 非线性可以提供有关组织的性质和疾病的信息。 我们最近描述了一种测量非线性参数的技术 B/A通过测量通过组织传播的声音的相位。为 更好的精确度和可靠性我们将把这项技术计算机化并使用 测定大量切除的人体组织的B/A。每个人 还将对样品进行脂肪-水组成和相关性分析， 如果有，将在B/A和组织成分之间建立。 此外，还将利用超声计算机辅助断层扫描来获得 通过测量声压幅值获得声学非线性图像 两个重合粒子传播产生的差频 不同频率的主波。 这项研究的结果将使我们能够评估 生物医学中的非线性声学。

The goals of this proposal are to determine 1) the degree of nonlinearity of human tissues, 2) how this information can be exploited to obtain reliable ultrasound images, and finally 3) what type of information nonlinearity can provide about the nature and disease of tissues. We have recently described a technique to measure the nonlinear parameter B/A by measuring the phase of sound transmitted through tissues. For better precision and reliability we will computerize the technique and use it to detemrine B/A for a large number of excised human tissues. Each sample will also be analyzed for fat-water composition and a correlation, if any, will be established between B/A and tissue composition. Also, ultrasound computer-assisted tomography will be utilized to obtain images of acoustic nonlinearity by measuring the perssure amplitude of the difference fequency generated from the propagation of two coincident primary waves of different frequencies. The results of this study will enable us to evaluate the potential role of nonlinear acoustics in biomedicine.