DIIFFUS COEFFICIE IN CAT BRAIN AT 94 T THE INVER LAPLACE TRANSFORM

94 T 时猫脑中的扩散系数拉普拉斯逆变换

基本信息

批准号：
7721363
负责人：
ITAMAR RONEN
金额：
$ 1.78万
依托单位：
UNIVERSITY OF MINNESOTA
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-06-01 至 2009-05-31
项目状态：
已结题

项目摘要

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. In this work, the usefulness of the inverse Laplace transformation (ILT) in the characterization of diffusion processes in the brain has been investigated. The method has been implemented on both phantom and in vivo cat brain data acquired at high resolution at 9.4 T. The results were compared with monoexponential and biexponential analyses of the same data. It is shown that in the case of diffusion restricted by white matter axonal tracts, the resulting diffusograms are in good agreement with the biexponential model. In gray matter, however, the non-monoexponential decay does not lead to a bimodal distribution in the ILT, even though the data can be fitted to a biexponential. This finding suggests the possibility of a distribution of diffusion coefficients rather than a discrete biexponential behavior. It is shown that this distribution is sensitive, for example, to experimental parameters such as the diffusion time. Thus, the ILT offers the possibility of implementing a unique tool for the analysis of heterogeneous diffusion, that is, the analysis of the diffusion coefficient distribution, which has the yet unexplored potential of being a valuable parameter in the characterization of tissue structure.

该子项目是利用该技术的众多研究子项目之一资源由 NIH/NCRR 资助的中心拨款提供。子项目及研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金，因此可以在其他 CRISP 条目中表示。列出的机构是对于中心来说，它不一定是研究者的机构。在这项工作中，研究了拉普拉斯逆变换 (ILT) 在表征大脑扩散过程中的有用性。该方法已在 9.4 T 高分辨率下获得的模型和活体猫脑数据上实施。结果与相同数据的单指数和双指数分析进行了比较。结果表明，在扩散受到白质轴突束限制的情况下，所得扩散图与双指数模型非常一致。然而，在灰质中，非单指数衰减不会导致 ILT 中的双峰分布，即使数据可以拟合为双指数。这一发现表明扩散系数分布而不是离散双指数行为的可能性。结果表明，该分布对扩散时间等实验参数很敏感。因此，ILT 提供了实现异质扩散分析的独特工具的可能性，即扩散系数分布分析，它具有作为组织结构表征中有价值的参数的尚未开发的潜力。