Angular Dependency of T1 Relaxation Time in Cerebral White Matter in Ultrahigh Field MRI

超高场 MRI 脑白质 T1 弛豫时间的角度依赖性

• 批准号: 9983056
• 负责人: MICHAEL GARWOOD
• 金额: $ 7.7万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9983056
• 关键词: Address; Adult; Advanced Development; Affect; Anisotropy; Axon; Biochemical; Biophysics; Brain; Brain imaging; Brain scan; Caliber; Cerebrum; Characteristics; Clinical; Clinical Medicine; Clinical/Radiologic; Complex; Data; Dependence; Diagnosis; Diffusion Magnetic Resonance Imaging; Disease; Fiber; Foundations; Goals; Human; Image; Immobilization; Investigation; Iron; MRI Scans; Magic; Magnetic Resonance Imaging; Magnetism; Measures; Mediating; Methods; Modernization; Morphology; Myelin; Nature; Neurobiology; Numerical value; Participant; Pathology; Physiologic pulse; Physiology; Predisposition; Process; Protocols documentation; Protons; Proxy; Recovery; Relaxation; Research; Role; Scanning; Source; Structure; Study of magnetics; Temperature; Time; Tissues; Vertebral column; Water; base; brain disorder diagnosis; brain morphology; brain tissue; clinical Diagnosis; contrast imaging; design; experimental study; improved; macromolecule; magnetic field; neuroimaging; novel; physical property; tool; white matter

PROJECT SUMMARY Contrast in magnetic resonance imaging (MRI) scans of the brain are influenced by complex interactions between water, brain macromolecules and microstructural compenents. The most commonly used MR relaxation-based contrasts change with magnetic field strength, because both T1 and T2 MR relaxation times are field dependent. At higher fields inherent tissue-specific factors, such as bulk magnetic susceptibility due to tissue microstructure and/or biochemical making, affect relaxation thereby influencing MRI contrast. For efficient and adequate use of MR images in neuroscientific research and clinical diagnosis, it is pivotal to understand effects of tissue-related factors on relaxation-based contrasts at clinical (such as 3 Tesla=T) and ultrahigh field (UHF, 7T or above) MRI. The thrust of the proposal is to study the angular dependency of T1 relaxation in human white matter (WM) at 3T and 7T. Our goal is to gain understanding of effects of MR-visible water on the angular dependency of T1 relaxation in WM. Experiments are designed to study the role of the magnetic field strength, axonal diameter and magnetization transfer in the fiber-to-field dependency of MR-visible water and T1 relaxation time. MRI data will be acquired from healthy adult participants at 3T and 7T. The specific aims of the project are as follows: AIM 1: to measure the amplitude of the angular dependency of MR-visible water and T1 relaxation time in WM and study its relationship with WM tracts axonal microstructure, such as axonal diameter. AIM 2: to study the magnetic field dependency of the amplitude of MR-visible water and T1 relaxation in WM. AIM3: to study the effects of magnetization transfer on the amplitude of the angular dependency of MR-visible water and T1 relaxation time in WM at 3T and 7T. The project adds to our long-term pursuit to advance understanding of biophysical underpinnings of MR contrasts in brain images. Our overarching goal is to improve delineation of tissue morphology by MRI for imaging of normal brain and its disorders in modern neuroimaging.

项目摘要 大脑的磁共振成像（MRI）扫描的对比度受复合物的影响 水，大脑大分子和微结构组合之间的相互作用。这 最常用的基于MR松弛的对比与磁场强度变化， 因为T1和T2 MR松弛时间都取决于场。在固有的较高田地 组织特异性因素，例如由于组织微观结构而引起的大量磁化率 和/或生化形成，影响放松，从而影响MRI对比。高效 在神经科学研究和临床诊断中充分使用MR图像，这是 关键以了解组织相关因素对临床基于松弛的对比的影响 （例如3个Tesla = T）和超高场（UHF，7T或更高）MRI。 该提议的目的是研究人类T1松弛的角度依赖性 白质（WM）在3t和7t。我们的目标是了解MR可视的影响 WM中T1松弛的角度依赖性的水。实验被设计为 研究磁场强度，轴突直径和磁化转移在 MR可见水和T1松弛时间的纤维对场依赖性。 MRI数据将是 从3T和7T的健康成人参与者中获得。该项目的具体目的是 以下内容：目标1：测量MR可视水的角度依赖性的幅度 WM中的T1松弛时间，研究其与WM道的关系，轴突微观结构， 例如轴突直径。目的2：研究磁场的振幅 WM中的MR可见水和T1松弛。 AIM3：研究磁化的影响 在MR可视水和T1弛豫的角度依赖性的幅度上转移 在3T和7T的WM中。 该项目增加了我们的长期追求，以提高对生物物理的理解 MR对比的基础在大脑图像中。我们的总体目标是改善 通过MRI描述组织形态的描述，用于成像正常脑及其疾病 现代神经影像学。