Imaging and modeling the biomechanics of large cerebral blood vessels using high-speed dynamic MRI

使用高速动态 MRI 对大脑血管的生物力学进行成像和建模

• 批准号: 9506007
• 负责人: Theodore James Huppert
• 金额: $ 19.37万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-15 至 2020-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9506007
• 关键词: Affect; Age; Angiography; Base Sequence; Biomechanics; Blood; Blood Flow Velocity; Blood Vessels; Brain; Cardiac Output; Cerebrovascular Disorders; Cerebrovascular system; Cerebrum; Chronic; Clinical; Dementia; Disease; Distal; Doppler Ultrasound; Elasticity; Electric Capacitance; Exploratory/Developmental Grant; Foundations; Frequencies; Functional disorder; Future; General Population; Goals; Head; Head and neck structure; Health; Heart Rate; Homeostasis; Hypertension; Hypertrophy; Image; Impairment; Isolated systolic hypertension; Link; Liquid substance; Magnetic Resonance Imaging; Maps; Mathematics; Measurement; Measures; Mechanics; Methods; Modeling; Modification; Patients; Perfusion; Phase; Physiology; Population; Property; Pulsatile Flow; Resistance; Risk; Rupture; Signal Transduction; Slice; Specificity; Speed; Stenosis; Stroke; Structure; Techniques; Ultrasonography; Vascular Diseases; Vascular blood supply; Vascular resistance; Venous; Work; base; biomechanical model; biophysical properties; blood flow measurement; cerebral artery; cerebral vein; cerebrovascular; clinically relevant; cranium; imaging approach; imaging modality; indexing; insight; malformation; mathematical model; mechanical properties; method development; normotensive; novel; novel strategies; physical property; power analysis; pressure; stroke risk; systolic hypertension

ABSTRACT The objective of this proposed R21 work is to develop and demonstrate a novel high-speed (10Hz) multi-slice dynamic MRI acquisition and model-based analysis technique to quantify the biomechanical properties of cerebral blood vessels. This novel approach measures T1-weighted inflow fluctuations (related to blood flow/velocity) in large arterial and venous blood vessels. Fluid mechanics model-based analysis is then applied to examine the frequency-dependent dampening and phase between velocity waveforms measured from proximal and distal ends of blood vessel segments allows the characterization of the biophysical properties of these segments including vascular resistance, inductance, and compliance. These high temporal signals are combined with structural MRI angiography to provide a spatial map of the blood vessel properties and topology. We believe that these quantifiable biomechanical and mathematical parameters can be linked to cerebral vascular diseases, since these directly reflect properties such as the rigidity and flow resistance of the vessels. The development of these methods has significant clinical implications toward quantitative assessment of cerebral vascular physiology in the context of vascular disorders such as hypertension, stenosis, and risk of stroke. As a proof-of-concept of this approach, and to initially investigate the sensitivity of this method, this technique will be applied to characterize the cerebral vascular properties of two groups of patients with chronic hypertension and isolated systolic hypertension in comparison to age-matched normotensive controls. The specific aims of this project are: Aim 1. Optimize methods for high-speed MR arterial compliance mapping. Aim 2. Demonstrate proof-of-concept for high-speed MR arterial compliance mapping in chronic hypertensive (HT) and isolated systolic hypertension (ISH) patients and compared to age-matched normotensive (NT) healthy controls. We hypothesize that: Hypothesis 1. Measurements of vascular resistance and compliance is sensitive to hypertrophic changes in HT and ISH patients and can be reliably measured using our proposed high-speed MR arterial compliance mapping approach. Hypothesis 2. HT and ISH patients will show increased resistance (stiffness) and decreased capacitance (compliance) compared to NT controls. These changes will be larger in the ISH group. The dynamic cerebral auto-regulation index (dCAI) will be impaired in both HT and ISH.

抽象的 这项拟议的R21工作的目的是开发和演示一种新型的高速（10Hz）多斜线 动态MRI获取和基于模型的分析技术，以量化 脑血管。这种新颖的方法测量了T1加权流入波动（与血液有关 在大动脉和静脉血管中流动/速度）。然后是基于流体力学模型的分析 用于检查测量的速度波形之间的频率减弱和相位 从血管段的近端和远端末端，可以表征生物物理 这些段的特性，包括血管抗性，电感和依从性。这些较高的时间 信号与结构性MRI血管造影结合在一起，以提供血管特性的空间图 和拓扑。 我们认为这些可量化的生物力学和数学参数可以与脑相关 血管疾病，因为这些疾病直接反映了诸如血管的刚度和流动性之类的特性。 这些方法的开发对定量评估具有重大临床意义 在血管疾病（例如高血压，狭窄和风险）的背景下，脑血管生理 中风。作为这种方法的概念验证，并最初研究了这种方法的敏感性， 技术将用于表征两组慢性患者的脑血管特性 与年龄匹配的正常性控制相比，高血压和孤立的收缩期高血压。这 该项目的具体目的是： AIM 1。优化高速MR动脉合规映射的方法。 AIM 2。在慢性中展示高速MR动脉合规映射的概念验证 高血压（HT）和孤立的收缩期高血压（ISH）患者，并与年龄匹配的患者进行比较 正常的（NT）健康对照。 我们假设这一点： 假设1。血管抵抗和依从性的测量对肥厚性变化敏感 HT和ISH患者，可以使用我们建议的高速MR依从性可靠地测量 映射方法。 假设2。HT和ISH患者将显示出较高的电阻（刚度）和电容降低 （合规）与NT对照相比。这些更改将在ISH组中更大。动态大脑 HT和ISH的自动调节指数（DCAI）将受到损害。