Imaging Brain Activation with Steady-State Free Precession MRI

使用稳态自由进动 MRI 对大脑激活进行成像

• 批准号: 7382796
• 负责人: John M. Pauly
• 金额: $ 32万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-10 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7382796
• 关键词: Age; Area; Biomedical Engineering; Blood; Blood capillaries; Brain; Brain imaging; Cities; Coupled; Data; Data Analyses; Depth; Development; Dropout; Electrical Engineering; Experimental Designs; Frequencies; Functional Magnetic Resonance Imaging; Goals; Human; Image; Imaging Techniques; Immunity; Invasive; Localized; Magnetic Resonance Imaging; Maps; Measures; Methods; Monitor; Morphologic artifacts; Nature; Neurons; Neurosciences; Numbers; Oxygen; Perfusion; Physics; Physiology; Procedures; Psychology; Radioactive Tracers; Radiology Specialty; Range; Research Project Grants; Resolution; Scanning; Signal Transduction; Source; Sterile coverings; Structure; Techniques; Technology; Tissues; Variant; Veins; Venous; Visual system structure; base; blood oxygen level dependent; capillary; computerized data processing; deoxyhemoglobin; image warping; improved; reconstruction; response; size; tool

DESCRIPTION (provided by applicant): Functional magnetic resonance imaging (fMRI) has revolutionized the neurosciences by providing noninvasive tools for monitoring changes in blood oxygenation or tissue perfusion associated with brain activation. The most common approach is blood oxygenation dependent (BOLD) imaging. Unfortunately, the MRI acquisition parameters that provide the oxygen sensitivity in BOLD also produce sensitivity to image artifacts, signal dropouts, and spatial distortion. The aim of this proposal is to develop alternatives to BOLD without these limitations. The new methods described in this proposal are based on oxygen-dependent signal changes in rapid, short TR, fully refocused imaging acquisition techniques, known as steady-state free precession, or SSFP. These approaches exploit the changes in the steady-state signal due to oxygenation changes. Once this steady-state oxygenation dependent contrast has been established, it can be captured with any image encoding method, which can be chosen for efficiency, resolution, and immunity to artifacts. The result is high-resolution, isotropic in any area of the brain, without signal dropouts or spatial distortion. This will be an important addition to the tools available to neuroscientists for studying brain activation. Specifically, this project aims to develop two different approaches for exploiting the SSFP response for fMRI. The first uses the frequency sensitivity of the SSFP transition band to detect absolute frequency shifts from blood oxygenation changes. The second exploits oxygen-dependent apparent T2 changes to the steady state magnetization. These techniques will then be evaluated and compared with conventional BOLD in well characterized studies of the visual system.

描述（由申请人提供）：功能磁共振成像（fMRI）通过提供无创的工具来监测血液氧合或与脑激活相关的组织灌注的变化，从而彻底改变了神经科学。最常见的方法是血液氧合依赖（粗体）成像。不幸的是，以BOLD提供氧气灵敏度的MRI采集参数也会对图像伪影，信号脱落和空间失真产生敏感性。该提议的目的是在没有这些限制的情况下开发替代替代方案。本提案中描述的新方法基于氧气依赖性信号变化，短，短TR，完全重新聚焦的成像采集技术，称为稳态无态进动或SSFP。这些方法利用了由于氧合变化而导致的稳态信号的变化。一旦建立了这种稳态氧合依赖性对比度，就可以使用任何图像编码方法捕获，该方法可以选择以效率，分辨率和对伪像的免疫力。结果是高分辨率，在大脑的任何区域中都处于各个区域，而没有信号脱落或空间失真。这将是神经科学家可用于研究大脑激活的工具的重要补充。具体而言，该项目旨在开发两种不同的方法来利用fMRI的SSFP响应。第一个使用SSFP过渡带的频率灵敏度来检测血液氧合变化的绝对频率转移。第二个利用氧依赖性的明显T2变化对稳态磁化的变化。然后，将对这些技术进行评估，并将其与传统的BOLD进行比较，以在视觉系统的良好特征研究中进行评估。