Towards pratical Mapping of Complex White Matter Fiber Pathways by Disffusion-Wei

通过扩散-魏实现复杂白质纤维通路的实用绘制

• 批准号: 7587052
• 负责人: Ken Earl Sakaie
• 金额: $ 19.48万
• 依托单位: CLEVELAND CLINIC LERNER COM-CWRU
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-30 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7587052
• 关键词: Achievement; Algorithms; Animal Model; Anisotropy; Area; Bilateral; Brain; Brain Pathology; Class; Classification; Clinical; Code; Complex; Computer software; Contralateral; Data; Data Analyses; Data Set; Development; Diagnosis; Diffusion; Diffusion Magnetic Resonance Imaging; Disease; Disruption; Entropy; Exhibits; Fiber; Functional Magnetic Resonance Imaging; Goals; Gold; Hour; Image; Image Analysis; Injury; Lateral; Lesion; Linux; Location; Magnetic Resonance Imaging; Manganese; Maps; Markov Chains; Measures; Methodology; Methods; Modeling; Monte Carlo Method; Motor; Motor Cortex; Motor Pathways; Multiple Sclerosis; Multiple Sclerosis Lesions; Nature; Neoplasms; Noise; Numbers; Pathology; Pathology, Other; Pathway interactions; Patient Care; Patients; Performance; Personal Satisfaction; Placement; Population; Precentral gyrus; Probability; Process; Property; Public Health; Purpose; Recruitment Activity; Relative (related person); Resolution; Seeds; Signal Transduction; Standards of Weights and Measures; Statistically Significant; Structure; Testing; Time; Tissues; Water; Weight; White Matter Disease; base; blood oxygen level dependent; clinical application; computing resources; cost; data acquisition; diffusion anisotropy; falls; gray matter; improved; in vivo; indexing; prevent; repaired; size; success; white matter; white matter damage

DESCRIPTION (provided by applicant): The overall objective of the proposed project is to develop a practical method for mapping white matter pathways over long distances in the brain through regions of complex fiber geometries even in the presence of pathology. Diffusion tensor-based deterministic streamline fiber tracking, using data from Diffusion-Weighted MRI (DW-MRI), can map highly organized white matter pathways, but fails upon encountering fiber crossings and low anisotropy regions typical of neoplasms and white matter disease. A number of functionally important white matter pathways cannot be mapped by conventional methods. The specific aim of the proposed project is to develop spherical deconvolution with objectively optimized regularization, a method for defining the Fiber Orientation Distribution (FOD), as the basis of probabilistic tracking to define the motor pathway in under one hour with conventional computing resources. The functionally important motor pathway encompasses numerous crossings. Although probabilisitic tracking based on persistent angular structure (PAS) estimation of the FOD has been shown to identify connections to the entire motor pathway, the computational cost of PAS is prohibitive, requiring on the order of 90 cpu-DAYS for an in vivo dataset. Spherical deconvolution with objectively optimized regularization requires two cpu-minutes. However, as PAS-based tracking has identified the entire motor area and has been validated in an animal model, it will serve as the basis for comparison in the absence of a readily accessible gold standard. The proposed project will therefore compare PAS and spherical deconvolution with objectively optimized regularization with regard to their performance in tracking the motor pathway. A 20-processor Linux cluster will enable the PAS calculation and will be used to optimize the spherical deconvolution method. DW-MRI data from 20 healthy subjects will be used to calculate FODs by spherical deconvolution with objectively optimized regularization and PAS as the basis of probabilistic tracking. Primary motor cortex, the seed regions for tracking, will be identified by BOLD-fMRI. Tracks that intersect both bilateral motor cortex regions will be identified as the motor pathway. The goal of this project will have been achieved if a statistically significant correlation between motor pathway identified by each method is found, and the total computation time is under one hour with conventional computing resources. The same analysis will be performed in 10 multiple sclerosis patients as a separate group to evaluate the methodology in the presence of disease. Upon achievement of the overall objective, progress toward a practical method for mapping white matter pathways will have been made. Due to a relative lack of anatomical landmarks on imaging, as compared with gray matter, the function associated with a given region of white matter and damage thereto can be unclear. Development of a more universally applicable method for defining white matter pathways will serve as the basis for improved presurgical planning and better assessment of the importance of injury or repair by therapy to regions of white matter. PUBLIC HEALTH RELEVANCE White matter in the brain contains functionally important connection pathways. The proposed project aims to develop a practical method for noninvasive mapping of pathways that are difficult or impossible to delineate with current methods, thus extending the utility of such mapping to the entire brain. Improved diagnosis of white matter disease, better assessment of the potential impact of lesions in white matter, and improved presurgical planning may therefore result.

描述（由申请人提供）：拟议项目的总体目标是开发一种实用方法，即使在存在病理的情况下，也可以通过复杂的纤维几何形状区域绘制大脑中长距离的白质路径。基于扩散张量的确定性流线纤维跟踪，使用扩散加权 MRI (DW-MRI) 的数据，可以绘制高度组织化的白质路径，但在遇到肿瘤和白质疾病典型的纤维交叉和低各向异性区域时会失败。许多具有重要功能的白质通路无法通过传统方法绘制。该项目的具体目标是开发具有客观优化正则化的球形反卷积，这是一种定义纤维方向分布（FOD）的方法，作为概率跟踪的基础，使用传统计算资源在一小时内定义运动路径。功能上重要的运动通路包含许多交叉点。尽管基于 FOD 持续角结构 (PAS) 估计的概率跟踪已被证明可以识别与整个运动路径的连接，但 PAS 的计算成本过高，对于体内数据集需要大约 90 个 cpu-DAYS。具有客观优化正则化的球形反卷积需要 2 个 cpu 分钟。然而，由于基于 PAS 的跟踪已经识别了整个运动区域，并已在动物模型中得到验证，因此在缺乏易于获取的金标准的情况下，它将作为比较的基础。因此，拟议的项目将比较 PAS 和球形反卷积与客观优化正则化在跟踪运动路径方面的性能。 20 处理器的 Linux 集群将支持 PAS 计算，并将用于优化球形反卷积方法。来自 20 名健康受试者的 DW-MRI 数据将用于通过球面反卷积计算 FOD，并以客观优化的正则化和 PAS 作为概率跟踪的基础。初级运动皮层（用于跟踪的种子区域）将通过 BOLD-fMRI 进行识别。与双侧运动皮层区域相交的轨迹将被识别为运动路径。如果发现每种方法识别的运动路径之间存在统计上显着的相关性，并且使用传统计算资源的总计算时间低于一小时，则该项目的目标就已实现。相同的分析将在 10 名多发性硬化症患者中作为一个单独的组进行，以评估在疾病存在的情况下的方法。实现总体目标后，将在绘制白质路径的实用方法方面取得进展。由于与灰质相比，成像上相对缺乏解剖标志，与白质给定区域相关的功能及其损伤可能不清楚。开发一种更普遍适用的方法来定义白质通路将作为改进术前计划和更好地评估白质区域治疗损伤或修复的重要性的基础。公共卫生相关性 大脑中的白质包含功能上重要的连接通路。该项目旨在开发一种实用方法，用于对用当前方法难以或不可能描绘的路径进行非侵入性绘图，从而将这种绘图的效用扩展到整个大脑。因此，可能会改进对白质疾病的诊断，更好地评估白质病变的潜在影响，并改进术前计划。