Parallel MRI for High Field Neuroimaging

用于高场神经成像的并行 MRI

• 批准号: 7675979
• 负责人: Victor Andrew Stenger
• 金额: $ 26.59万
• 依托单位: UNIVERSITY OF HAWAII AT MANOA
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7675979
• 关键词: Address; Amplifiers; Amygdaloid structure; Basal Ganglia; Basic Science; Behavior; Brain; Brain region; Clinical; Clinical Research; Corpus striatum structure; Coupling; Data; Decision Making; Dependence; Development; Disease; Drug Addiction; Drug abuse; Drug user; Event; Financial compensation; Functional Magnetic Resonance Imaging; Human Volunteers; Image; Imaging Techniques; Inferior; Left; Length; Magnetic Resonance Imaging; Magnetism; Methamphetamine; Methodology; Methods; Monitor; Morphologic artifacts; National Institute of Drug Abuse; Noise; Nucleus Accumbens; Outcome; Pattern; Phase; Physiologic pulse; Pilot Projects; Play; Population; Predisposition; R-factor; Research; Research Personnel; Resolution; Rewards; Risk; Shapes; Signal Transduction; Slice; Solutions; Structure; Substance abuse problem; Sum; Techniques; Testing; Variant; Ventral Striatum; Work; addiction; clinical application; data acquisition; design; high risk; improved; magnetic field; neural circuit; neuroimaging; neuromechanism; neuropsychiatry; novel; programs; reconstruction; research study; resistance factors; reward processing; tool; transmission process

DESCRIPTION (provided by applicant): Magnetic Resonance Imaging (MRI) at high field strengths is a n invaluable tool for non-invasively studying brain structure and function in clinical populations. Higher magnetic fields provide greater signal to noise and increased contrast in functional MRI (fMRI). For example, the use of fMRI is crucial for understanding the neural mechanisms underlying reward processing and decision-making, which are likely to be associated with an increased risk of drug abuse. Understanding the altered brain circuitry in populations with drug dependencies is vital to finding effective, lasting treatments. Although it has now possible to use MRI at high fields to investigate neural circuitry and brain structure in clinical research, these studies are severely hampered by critical methodological limitations including magnetic susceptibility artifacts and RF field inhomogeneity. Susceptibility artifacts produce signal loss in many key brain regions such as the ventral striatum, amygdala, orbitofrontai cortex, basal ganglia, and nucleus accumbens. All of these regions are vital to understanding reward and addiction as well as numerous other neuropsychiatric disorders. Furthermore, the high fields needed for improved fMRI contrast also produce large image intensity variations and artifacts associated with the wavelike behavior of the RF field. These problems become worse as the field strength increases and currently leave ultra-high field scanners such as 7T impractical for clinical use. In the present application, which is a continuation of R21-DA15900, our group of investigators will tackle these technical limitations and develop and validate solutions designed to improve our ability to investigate the brain at high field. Specifically, we will design, build, and validate the use sensitivity encoding with multiple transmitters (XSENSE) to create practical implementations of tailored RF pulses at 3T. The tailored RF pulses will be used to shape MRI excitations, producing slices with improved homogeneity and less signal loss. We will combine parallel transmission with parallel reception for further refinements in image accuracy. Whole brain acquisitions for fMRI and structural MRI will be created and carefully characterized. The fMRI sequence will allow for the imaging of inferior brain regions, making new clinical applications possible. The structural MRI sequence will be robust to RF field inhomogeneity and will be tested at 7T as well. The techniques will be validated and compared in healthy human volunteers and then in an fMRI pilot study of the reward circuit in a population of abstinent drug users and controls.

描述（由申请人提供）：高场强度下的磁共振成像（MRI）是非侵入性研究临床种群中大脑结构和功能的N无价工具。较高的磁场为噪声提供了更大的信号，并增加了功能性MRI（fMRI）的对比度。例如，fMRI的使用对于理解奖励处理和决策的神经机制至关重要，这些神经机制可能与增加药物滥用风险有关。了解药物依赖性种群中脑电路的改变对于寻找有效的持久治疗至关重要。尽管现在有可能在高场上使用MRI来研究临床研究中的神经回路和大脑结构，但这些研究受到关键方法学局限性的严重阻碍，包括磁敏感性伪像和RF场不均匀性。易感性伪影在许多关键的大脑区域（例如腹侧纹状体，杏仁核，甲状腺素皮层，基底神经节和八核）产生信号丧失。所有这些地区对于理解奖励和成瘾以及许多其他神经精神疾病至关重要。此外，改善fMRI对比所需的高场还产生了与RF场的波浪行为相关的大图像强度变化和伪像。随着野外强度的增加，这些问题变得更糟，目前留下超高的野外扫描仪，例如7T不切实际的临床使用。在本应用程序（R21-DA15900的延续）中，我们的研究人员将应对这些技术局限性，并开发和验证旨在提高我们在高领域调查大脑的能力的解决方案。具体来说，我们将使用多个发射器（XSENSE）设计，构建和验证使用敏感性编码，以创建3T定制的RF脉冲的实际实现。量身定制的RF脉冲将用于塑造MRI激发，产生具有改善均匀性和较少信号损失的切片。我们将将平行传输与平行接收相结合，以进一步改进图像精度。将创建和仔细表征fMRI和结构MRI的全脑习得。 fMRI序列将允许下脑区域的成像，从而使新的临床应用成为可能。结构MRI序列将对RF场不均匀性具有鲁棒性，并且也将在7T处进行测试。这些技术将在健康的人类志愿者中进行验证和比较，然后在符合戒毒者和控制措施的人群中对奖励电路的fMRI试点研究中进行比较。