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: 6490958
• 负责人: THOMAS EDWARD CONTURO
• 金额: $ 44.1万
• 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/6490958
• 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.

我们建议通过磁共振成像（MRI）来扩展我们的开发，以追踪人脑内层的神经元纤维。该方法称为扩散张量跟踪 (DTT)，从扩散张量编码的 MRI 数据 (DT-MRI) 重建神经元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，能够研究人类独特的连接解剖结构，并且能够与同一个体受试者的功能磁共振成像激活直接相关，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（例如语言）相关的联系尤其重要，而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，我们将进一步增强当前对 DT-MRI 数据的三维全脑纤维轨迹的计算，并开发和完善选择不同纤维组的方法，特别是包括由功能磁共振成像定义的区域之间的连接。对于 Aim II，我们将通过计算机模拟和实验数据的反复测试评估来评估 DTT 纤维轨迹的准确性和精度。在目标 III 中，我们将使用已知的猴子神经解剖学作为标准，评估 DTT 确定 fMRI 定义的初级感觉与体感和视觉系统中高阶区域之间连接的能力。视觉研究将涉及视网膜专题功能磁共振成像映射，以识别更高的视觉区域并选择膝关节束的功能子集，以及运动感知研究，以激活视觉皮层之外的远程认知区域。对于目标 IV，我们将检查 DTT 的潜在临床效用，通过将病变到皮质 DTT 投影与视网膜专题 fMRI 中的皮质缺陷以及膝局部病变患者的视野缺陷相关联，来表征白质病变的功能影响。在 Aim V 中，我们将比较视力正常、早期失明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。拟议研究的成功完成将为研究正常和疾病状态下人脑的发育、功能组织和重组提供一套经过测试的工具。