BASIC STUDIES IN ULTRASONIC ELASTOGRAPHY

这项工作的基本假设是横截面图像 (弹性图)与软体的局部体积杨氏模数有关 组织[Ophir等人，1991]传达了新的信息，可以 大大提高了显示和解释组织的能力 结构在相应的常规声像图中。 为了检验这一假设，我们提出了以下具体目标： (1)调查影响敏感度的因素和权衡， 动态范围、分辨率和信噪比性能 弹性图。 (2)识别和调查可能存在的人工制品的来源 以弹性图表示。 (3)生成模拟体模的组织和正常牛的弹性图 肌肉的体外培养。比较弹性图导出的弹性值 到独立获得的弹性值。 (4)比较组织的超声和弹性成像可视化。 人体前列腺的体外结构。 (5)测量和分类乳房和前列腺的弹性特性 体外培养的组织。 初步工作表明：(1)存在可测量的范围 与正常组织相关的弹性(想必也与 病理组织)；(2)弹性成像能够产生弹性 基于图像(弹性图)，具有足够的分辨率和 可视化非均质复杂弹性结构的敏感度 活体软组织；(3)组织的结构信息 通过弹性成像显示的图像可能无法以其他方式获得。 这里提出的工作旨在为一些基本的问题提供答案 问题；这些问题与弹性成像的各个方面有关， 从基础物理开始，到信号处理和 最优化，并结束于图像形成和解释。这个 预计答案将把弹性图形学放在一个坚实的理论和 实验基础，从而允许扩展功能 诊断性超声成像。

The underlying hypothesis in this work is that cross-sectional images (elastograms) which are related to the local bulk Young's moduli of soft tissue [Ophir et al, 1991] convey new information which could substantially increase the capability to display and interpret tissue structure in corresponding conventional sonograms. In order to test this hypothesis, we propose the following specific aims: (1) Investigate the factors and tradeoffs which influence the sensitivity, dynamic range, resolution and signal-to-noise ratio performance of elastograms. (2) Identify and investigate the origin of artifacts which may be present in elastograms. (3) Generate elastograms of tissue mimicking phantoms and of normal bovine muscle in vitro. Compare the elastographically derived elasticity values to elasticity values obtained independently. (4) Compare the sonographic and elastographic visualization of tissue structures in human prostates in vitro. (5) Measure and catalog the elastic properties of breast and prostate tissues in vitro. Preliminary work has shown that (1) there is a measurable range of elasticities associated with normal tissues (and presumably also with pathological tissues); (2) elastography is capable of producing elasticity based images (elastograms), which are of sufficient resolution and sensitivity to visualize the complex elastic structure of heterogeneous soft tissues in vivo; and (3) the structural information of tissue displayed by elastography may not be otherwise obtainable. The work proposed here is intended to provide answers to some fundamental questions; these questions pertain to all aspects of elastography, starting from the basic physics, through signal processing and optimization, and ending in image formation and interpretation. The answers are expected to put elastography on a firm theoretical and experimental foundation, thereby allowing expansion of capabilities of diagnostic ultrasound imaging.