Structural dynamics of the human brain in vivo from tagged MRI and MR elastography.

来自标记 MRI 和 MR 弹性成像的人脑体内结构动力学。

• 批准号: 10382911
• 负责人: Jordan De Niro Escarcega
• 金额: $ 4.63万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10382911
• 关键词: 3-Dimensional; Acceleration; Adult; Affect; Age; American; Anatomy; Anterior; Brain; Brain region; Communities; Computer Models; Data; Data Set; Development; Equipment; Female; Frequencies; Gender; Head; Helmet; Human; Imaging Techniques; Impulsivity; Injury; Lateral; Lead; Left; Light; Magnetic Resonance Elastography; Magnetic Resonance Imaging; Measurement; Measures; Mechanics; Methods; Modality; Motion; Neck; Patients; Pattern; Physiological; Play; Prevention; Process; Property; Research; Research Personnel; Role; Rotation; Shapes; TBI treatment; Time; Tissues; Traumatic Brain Injury; Work; age group; assault; automobile accident; brain magnetic resonance imaging; brain tissue; chronic traumatic encephalopathy; computer generated; contact sports; cranium; design; elastography; experimental study; head impact; human subject; in vivo; injured; male; multidimensional data; response; severe injury; sex; vibration

PROJECT SUMMARY/ABSTRACT Traumatic brain injury (TBI) is widespread and potentially debilitating, and multiple mild head impacts can potentially cause chronic traumatic encephalopathy (CTE). Despite its importance, the underlying mechanics of the brain’s response to skull acceleration are not fully understood. This project is designed to identify and characterize natural modes of oscillation in the living human brain, using magnetic resonance imaging (MRI) of the brain during mild head accelerations (either very light impacts or low-amplitude vibration). Modes of oscillation are types of motion to which the brain is particularly vulnerable; such modes can be activated by skull motion in specific directions with particular frequency components. In preliminary studies I have identified seemingly consistent modes of oscillation in brains of 19 human subjects, by analyzing displacement and strain data sets from tagged MRI with a method known as dynamic mode decomposition. In this project, I hypothesize that the dominant natural modes of oscillation in particular, and the dynamic response of the brain to skull excitation in general, will be similar across all subjects, but the parameters of the response will differ quantitatively in subjects of different age and gender (due to differences in size, shape, and stiffness). In Aim 1, I will identify and characterize modes of oscillation in the human brain, again using dynamic mode decomposition of tagged MRI data, in groups of subjects of different ages and genders. Specifically I will quantify the damped natural frequencies, damping ratios, modal coefficients, and spatial patterns (mode shapes) that characterize each mode. These quantities will be obtained for male and female subjects in three age groups, during two different types of head motion: (i) anterior-posterior motion (neck extension, or “yes” nodding) and (ii) axial rotation (neck rotation, or “no” nodding). In Aim 2 I will determine the frequency response of the human brain to harmonic skull motion using magnetic resonance elastography (MRE), again in subjects of different ages and genders. This will be done to determine whether the harmonic brain deformations observed in MRE reflect anatomical or physiological differences due to age or sex. MRE studies will be performed over a range of frequencies, with either occipital excitation (anterior-posterior motion) or lateral excitation (right-left motion). A key feature of the brain’s response is the amplitude of brain deformation (shear strain amplitude) relative to the amplitude of skull acceleration. This ratio is expected to vary with the direction and frequency of skull motion, as well as with age and sex. Successful completion of these Aims will provide quantitative understanding of how skull motion leads to brain deformation in specific regions of the brain, under different impact scenarios, and allow quantitative assessment of computer models of TBI. This understanding will ultimately be critical to effective prevention and treatment of TBI and CTE.

项目摘要/摘要 创伤性脑损伤（TBI）是广泛的，可能使人衰弱，并且有多种轻度的头部影响可以 可能引起慢性创伤性脑病（CTE）。尽管它的重要性是 大脑对颅骨加速度的反应尚未完全理解。该项目旨在识别和 使用磁共振成像（MRI）来表征活体大脑中振荡的自然模式 轻度头部加速度的大脑（非常轻的冲击或低振幅振动）。模式 振荡是大脑特别脆弱的运动类型。这样的模式可以被头骨激活 在特定频率组件的特定方向上运动。在初步研究中，我已经确定 通过分析位移和应变，看似一致的19个人类受试者大脑的振荡模式 使用称为动态模式分解的方法从标记的MRI进行数据集。在这个项目中，我假设 尤其是振荡的主要自然模式，以及大脑对头骨的动态反应 一般而言，兴奋在所有受试者中都会相似，但是响应的参数将在定量上不同 在AIM 1中，我将确定 并表征人脑中振荡模式，再次使用标记的动态模式分解 MRI数据，不同年龄和性别的受试者组。具体而言，我将量化阻尼的自然 频率，跳舞比，模态系数和空间模式（模式形状） 模式。在两个不同的情况下，将为三个年龄组的男性和女性受试者获得这些数量 头部运动的类型：（i）前后运动（颈部伸展或“是”点头）和（ii）轴向旋转（颈部 旋转或“否”点头）。在AIM 2中，我将确定人脑对谐波头骨的频率响应 在不同年龄和性别的受试者中，使用磁共振弹性图（MRE）进行运动。这会 完成以确定在MRE中观察到的谐波大脑变形是反映解剖学还是 由于年龄或性别引起的生理差异。 MRE研究将在一系列频率上进行，并具有 枕骨兴奋（前后运动）或横向兴奋（右左运动）。的关键特征 大脑的响应是相对于颅骨放大器的大脑变形（剪切应变放大器）的放大器 加速度。预计该比率将随颅骨运动的方向和频率而变化，并且随着年龄的增长 和性。这些目标的成功完成将提供对颅骨运动如何线索的定量理解 在大脑的特定区域，在不同的影响场景下，并允许定量 评估TBI的计算机模型。这种理解最终对于有效的预防和 TBI和CTE的处理。