QUANTITATION OF DIFFUSION EFFECTS IN MR IMAGING OF BRAIN

大脑 MR 成像中扩散效应的量化

• 批准号: 6393629
• 负责人: JIANHUI ZHONG
• 金额: $ 24.44万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-05-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6393629
• 关键词: Aplysia; alternatives to animals in research; bioimaging /biomedical imaging; brain circulation; brain disorder diagnosis; cell water; clinical research; computer simulation; diagnosis design /evaluation; diagnosis quality /standard; diffusion; disease /disorder model; generalized seizures; human subject; immunocytochemistry; kindling; laboratory rat; magnetic resonance imaging; mathematical model; method development; nuclear magnetic resonance spectroscopy; phantom model; stroke

This is a competing renewal of a grant that has been funded by the NIH. In the next phase of the project, we plan to continue to achieve the general aims at quantitation of diffusion effects in MR imaging of brain. In the past four years since the beginning of the current funding period, great progress has been made in the understanding of molecular diffusion in tissues, and in the development of new clinical applications of diffusion-weighted MR imaging. New questions, however, have emerged and new techniques have opened up new opportunities for better quantitation and further development. In the next phase we plan to develop new spectroscopy and imaging methods, and concentrate on the following areas: (1) Contributions of blood microcirculation and cytoplasmic streaming to apparent diffusion coefficient (ADC). We will develop methods based on the Velocity Exchange Spectroscopy (VEXSY) (Callaghan et al 1995) to detect water movement of different degrees of correlation and coherence. (2) Changes in ADC with alterations of properties of cellular compartments associated with brain injury. We will use signals from multiple-quantum transition and VEXSY method to detect water diffusion in different environments under controlled cellular morphological changes, and we will measure compartmental tortuosity. (3) Effects of magnetic susceptibility on ADC. New methods will be developed to selectively detect and quantify internal field gradients induced by magnetic susceptibility distributions. (4) Relationship between the ADC and neuronal electrical activities. We will use electrical stimulation of varying duration and intensity to study a rat kindling model of seizures with well characterized anatomic and functional network. We will correlate ADC changes with electrophysiological and immunocytochemistry measurements. (5) diffusion anisotropy changes associated with pathologic conditions or cerebral activity. We will use rat kindling and forepaw stimulation models in electrical stimulation studies, and human volunteers in activation studies. In all these areas, we will continue to use computer simulations to help in the experiment design, validation and quantitation of the results. The project will focus on studies with phantoms, animals, and human volunteers to look at biophysical basis of diffusion and its alteration during brain injury, but the outcomes from these studies should have a direct impact on brain diffusing imaging in a wide range of clinical settings.

这是对NIH资助的赠款的竞争更新。 在项目的下一个阶段，我们计划继续实现大脑MR成像中扩散效应的一般目标。 自当前资助期开始以来的过去四年中，在理解组织中的分子扩散以及扩散加权MR成像的新临床应用方面取得了巨大进展。 但是，新的问题已经出现，新技术为更好的定量和进一步发展开辟了新的机会。 在下一个阶段，我们计划开发新的光谱和成像方法，并集中于以下区域：（1）血液微循环和细胞质流对明显扩散系数（ADC）的贡献。 我们将根据速度交换光谱（Vexsy）（Callaghan等，1995）开发方法，以检测不同程度的相关性和相干性的水运动。 （2）ADC的变化随与脑损伤相关的细胞隔室特性的改变。 我们将使用来自多量化转变和烦恼方法的信号在受控的细胞形态变化下检测不同环境中的水扩散，我们将测量分隔曲折的曲折。 （3）磁敏感性对ADC的影响。 将开发新的方法来选择性检测和量化由磁敏感性分布引起的内部场梯度。 （4）ADC与神经元电活动之间的关系。 我们将使用对不同持续时间和强度的电刺激来研究具有良好表征解剖和功能网络的癫痫发射模型。我们将将ADC的变化与电生理和免疫细胞化学测量相关联。 （5）扩散各向异性与病理条件或脑活动相关的变化。 在电刺激研究中，我们将使用大鼠点燃和前线刺激模型，以及在激活研究中的人类志愿者。 在所有这些领域，我们将继续使用计算机模拟来帮助实验设计，验证和定量结果。该项目将着重于对幻影，动物和人类志愿者的研究，以研究扩散的生物物理基础及其在脑损伤期间的改变，但是这些研究的结果应直接影响在广泛的临床环境中脑扩散成像。