Parallel MRI for High Field Neuroimaging

用于高场神经成像的并行 MRI

• 批准号: 7908869
• 负责人: Victor Andrew Stenger
• 金额: $ 26.32万
• 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/7908869
• 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）：高场强磁共振成像（MRI）是非侵入性研究临床人群大脑结构和功能的宝贵工具。较高的磁场可提供更大的信噪比并提高功能 MRI (fMRI) 的对比度。例如，功能磁共振成像的使用对于理解奖励处理和决策背后的神经机制至关重要，这可能与药物滥用风险增加有关。了解药物依赖人群的大脑回路变化对于寻找有效、持久的治疗方法至关重要。尽管现在可以在临床研究中使用高场 MRI 来研究神经回路和大脑结构，但这些研究受到关键方法学限制的严重阻碍，包括磁化率伪影和射频场不均匀性。敏感性伪影会导致许多关键大脑区域的信号丢失，例如腹侧纹状体、杏仁核、眶额皮层、基底神经节和伏隔核。所有这些区域对于理解奖励和成瘾以及许多其他神经精神疾病都至关重要。此外，改善功能磁共振成像对比度所需的高场也会产生大的图像强度变化和与射频场的波状行为相关的伪影。随着场强的增加，这些问题变得更加严重，并且目前 7T 等超高场扫描仪在临床使用中不切实际。在本申请（R21-DA15900 的延续）中，我们的研究小组将解决这些技术限制，并开发和验证旨在提高我们在高场研究大脑的能力的解决方案。具体来说，我们将设计、构建和验证使用多个发射器 (XSENSE) 的灵敏度编码，以创建 3T 定制 RF 脉冲的实际实现。定制的射频脉冲将用于塑造 MRI 激励，产生均匀性更高、信号损失更少的切片。我们将并行传输与并行接收相结合，以进一步提高图像精度。将创建用于功能磁共振成像和结构磁共振成像的全脑采集并仔细表征。功能磁共振成像序列将允许对下脑区域进行成像，使新的临床应用成为可能。结构 MRI 序列对于 RF 场不均匀性具有鲁棒性，并且也将在 7T 下进行测试。这些技术将在健康人类志愿者中进行验证和比较，然后在戒毒者和对照人群中进行奖励回路的功能磁共振成像试点研究。