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.

项目概要 大脑磁共振成像 (MRI) 扫描的对比度受到复杂因素的影响 水、脑大分子和微观结构成分之间的相互作用。这 最常用的基于 MR 弛豫的对比度随磁场强度的变化而变化， 因为 T1 和 T2 MR 弛豫时间均与场相关。在更高的固有领域 组织特异性因素，例如组织微观结构导致的体磁化率 和/或生化制造，影响放松，从而影响 MRI 对比度。为了高效 以及在神经科学研究和临床诊断中充分利用 MR 图像， 了解组织相关因素对临床松弛对比的影响至关重要 （如3特斯拉=T）和超高场（UHF、7T或以上）MRI。 该提案的主旨是研究人类 T1 弛豫的角度依赖性 3T 和 7T 的白质 (WM)。我们的目标是了解 MR-visible 的影响 水对 WM 中 T1 弛豫的角度依赖性。实验旨在 研究磁场强度、轴突直径和磁化传递的作用 MR-可见水和 T1 弛豫时间的光纤与场依赖性。 MRI 数据将是 在 3T 和 7T 时从健康成人参与者处获得。该项目的具体目标是 如下： 目标 1：测量 MR 可见水的角度依赖性的幅度 WM中的T1弛豫时间并研究其与WM束轴突微结构的关系， 例如轴突直径。目标 2：研究振幅的磁场依赖性 WM 中的 MR 可见水和 T1 弛豫。 AIM3：研究磁化的影响 MR-可见水和 T1 弛豫的角度依赖性幅度的传递 WM 时间为 3T 和 7T。 该项目增强了我们对促进生物物理学理解的长期追求 大脑图像中 MR 对比的基础。我们的首要目标是改进 通过 MRI 描绘组织形态，以对正常大脑及其疾病进行成像 现代神经影像学。