ACOUSTIC NONLINEARITY FOR TISSUE CHARACTERIZATION

本提案的目标是确定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3）什么类型的信息 非线性可以提供关于组织的性质和疾病。 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输的声音的相位。 为 更好的精度和可靠性，我们将计算的技术和使用 确定大量切除人体组织的B/A。 每个 还将分析样品的脂肪-水组成和相关性， 如果有的话，将在B/A和组织成分之间建立。 此外，超声计算机辅助断层扫描将用于获得 图像的声学非线性通过测量的压力振幅的 由两个重合的传播产生的差频 不同频率的基波。 这项研究的结果将使我们能够评估的潜在作用， 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.