TRACKING NEURONAL FIBERS IN LIVING HUMAN BRAIN BY MRI

通过 MRI 追踪活人大脑中的神经纤维

• 批准号: 6291641
• 负责人: THOMAS EDWARD CONTURO
• 金额: $ 38.71万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-01-27 至 2005-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6291641
• 关键词: age difference; bioimaging /biomedical imaging; blindness; brain imaging /visualization /scanning; clinical research; computer simulation; contrast media; diagnosis design /evaluation; diagnosis quality /standard; eye disorder diagnosis; functional magnetic resonance imaging; human subject; magnetic resonance imaging; method development; motion perception; neurons; noninvasive diagnosis; psychomotor tracking; somesthetic sensory cortex; visual cortex; visual pathways; visual tracking

We propose to extend our developments with magnetic resonance imaging (MRI) for tracking neuronal fibers in the lining human brain. The method, called diffusion tensor tracking (DTT), reconstructs continuous threedimensional trajectories of neuronal fiber bundles from diffusion tensor-encoded MRI data (DT-MRI). Compared to other methods, the MR procedure is non-invasive, capable of studying connectional anatomy unique to humans, and amenable to direct correlation with fMRI activations in the same individual subjects, which potentially will uncover the neuronal connections used for human tasks. Noninvasive DTT methods are especially important for revealing connections in humans associated with cognitive functions like language that cannot be extrapolated from non-human primate studies. For Aim I we will further enhance current computations of three- dimensional whole-brain fiber trajectories from DT-MRI data and develop and refine methods for selecting different fiber groups, especially including connections between regions defined by fMRI. For Aim II we will evaluate the accuracy and precision of DTT fiber trajectories by computer simulation and test-retest evaluation of experimental data. In Aim III we will assess the ability of DTT to determine the connectivity between fMRI-defined primary sensory and higher-order regions in the somatosensory and visual systems using known monkey neuroanatomy as a standard. The visual studies will involve retinotopic fMRI mapping to identify higher visual areas and to select functional subsets of the geniculocalcarine tract, and motion perception studies to activate remote cognitive regions outside the visual cortex. For Aim IV we will examine the potential clinical utility of DTT to characterize the functional effects of white matter lesions by correlating the lesion-to-cortex DTT projections with cortical defects in retinotopic fMRI and with visual field defects in patients with focal lesions of the geniculocalcarine tract. In Aim V, we will compare visual cortex connections in sighted, early- and late-blind subjects to assess the effects of age of blindness on the development and organization of the visual system. Successful completion of the proposed research will provide a set of tested tools for interrogating the development, functional organization, and reorganization of the human brain in normal and disease.

我们建议扩展我们的发展与磁共振成像（MRI）跟踪神经纤维在内衬人脑。该方法被称为扩散张量跟踪（DTT），从扩散张量编码的MRI数据（DT-MRI）重建神经纤维束的连续三维轨迹。与其他方法相比，MR程序是非侵入性的，能够研究人类特有的连接解剖结构，并且能够与同一个体受试者的fMRI激活直接相关，这可能会揭示用于人类任务的神经元连接。非侵入性DTT方法对于揭示人类与认知功能（如语言）相关的联系尤为重要，这些联系无法从非人类灵长类动物研究中推断出来。对于目标I，我们将进一步增强目前从DT-MRI数据中计算三维全脑纤维轨迹的能力，并开发和改进选择不同纤维组的方法，特别是包括功能MRI定义的区域之间的连接。对于目标II，我们将通过计算机模拟和实验数据的重测评估来评估DTT光纤轨迹的准确性和精度。在目标III中，我们将评估DTT的能力，以确定之间的连接功能磁共振成像定义的初级感觉和高阶区域的躯体感觉和视觉系统使用已知的猴子神经解剖学作为标准。视觉研究将涉及视网膜定位功能磁共振成像映射，以确定更高的视觉区域，并选择功能子集的geniculocalcarine道，和运动感知研究，以激活远程认知区域以外的视觉皮层。对于目标IV，我们将研究DTT的潜在临床效用，通过将病变到皮质的DTT预测与视网膜功能MRI中的皮质缺陷和geniculocalcarine束局灶性病变患者的视野缺陷相关联，来表征白色病变的功能效应。在目标V中，我们将比较有视力、早期和晚期失明受试者的视觉皮层连接，以评估失明年龄对视觉系统发育和组织的影响。成功完成拟议的研究将提供一套经过测试的工具，用于询问正常和疾病中人脑的发育，功能组织和重组。