Novel Acquisition Methods for Diffusion MRI

扩散 MRI 的新采集方法

• 批准号: 7379478
• 负责人: ROLAND BAMMER
• 金额: $ 39.07万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-01 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7379478
• 关键词: Adult; Algorithms; Area; Award; Budgets; Calendar; Child; Childhood; Clinical; Communities; Complex; Data; Databases; Deposition; Detection; Development; Diagnosis; Diffusion; Diffusion Magnetic Resonance Imaging; Diffusion weighted imaging; Dimensions; Disease; Drops; Enrollment; Entropy; Evaluation; Faculty; Fiber; Figs - dietary; Frequencies; Functional disorder; Funding; Future; Goals; Guidelines; Hand; Head; Image; Immune; Immunity; Individual; Investigation; Left; MRI Scans; Magnetic Resonance Imaging; Maps; Measures; Methods; Metric; Motion; Nature; Neurosciences; Noise; Occupations; Pathologic; Pathway interactions; Patients; Pattern; Phase; Physiological; Positioning Attribute; Posture; Process; Protocols documentation; Protons; Radial; Real-Time Systems; Recording of previous events; Registries; Research; Research Project Grants; Research Proposals; Residual state; Resolution; Rotation; Sample Size; Sampling; Scanning; Scheme; Scientist; Signal Transduction; Slice; Techniques; Testing; Time; United States National Institutes of Health; Update; Upper arm; Variant; Vision; Wages; Weight; Work; clinical application; cost; data space; experience; image reconstruction; improved; insight; magnetic field; millisecond; morphometry; motion sensitivity; novel; peer; prospective; reconstruction; response; simulation; tumor; volunteer; water diffusion; white matter

MOTIVIATION - One of MRI’s inherent biophysical contrast parameters is proton self-diffusion, which can be measured by diffusion-weighted imaging (DWI). A variant, Diffusion Tensor Imaging (DTI), is an MRI method for noninvasive quantitative mapping of anisotropic water diffusion, thereby allowing the non-invasive investigation of white matter (WM) microstructure which might aid in the diagnosis and understanding the pathophysiology of white matter abnormalities and delayed maturation. DTI has been also used extensively for non-invasive tracing of WM pathways in tumor patients and in patients harboring non-focal disease. Unfortunately, DTI still suffers not only from physiologic motion but also from profound technical difficulties that increase with higher magnetic fields; higher magnetic fields on the other hand would offer substantially more signal-to-noise ratio (SNR). One of the major benefactors from motion-compensated DTI at high field would be children because of their smaller head sizes and the higher likelihood of motion. AIMS - The overarching goal of this 2-year research effort is to improve diffusion-weighted multi-shot spiral imaging to create significant improvements in 2D and 3D diffusion tensor imaging. Specifically, the project focuses on improvements for spiral acquisition methods and corresponding reconstruction techniques that reduce distortions, improve immunity to motion, diminish RF deposition, and provide better spatial resolution. Special emphasis is also given on improving image quality of this sequence for pediatric imaging. The specific aims are: (Specific Aim #1) to develop and optimize acquisition and reconstruction methods for real-time spiral diffusion-weighted MRI for 2D and 3D acquisitions; (Specific Aim #2) to define optimal DTI scan parameters for 2D and 3D for adults and children at 3T and 7T for different clinical applications and variants of motion. METHODS - Navigator, (prospective and retrospective) motion and off-resonance correction schemes in concert with augmented parallel imaging reconstruction algorithms will be developed and optimized both in simulations and phantom studies. Healthy children (n=62) and adults (n=30) will be enrolled for extensive testing. Optimal DTI scan parameters for a battery of different clinical questions and variants of motion will be determined by experienced neuroimagers and neuroradiologists. The raw k-space data and high-resolution diffusion tensor data will be added to a registry and can be made available to the public to improve image reconstruction algorithms (e.g. off-resonance correction, parallel imaging, diffusion phase navigation, gridding reconstruction), tensor processing (e.g. studying partial volume effects, crossing fibers, complex tract tracing algorithms) and to provide a normative database for adults and children that can be used in future trials. SIGNIFICANCE –We believe that upon successful completion of this project significant improvements in DTI can be achieved that will improve morphometric assessment and tract tracing in patients harboring various pathologic conditions. Abnormalities in WM and tract projections could provide crucial insights in the pathophysiology of several diseases that attack white matter, and further the understanding of specific neurodevelopmental trajectories of children with and without WM disorders.

动机 - MRI固有的生物物理对比参数之一是质子自扩散，可以通过扩散加权成像（DWI）来衡量。一种变体的扩散张量成像（DTI）是一种MRI方法，用于无创定量映射各向异性水扩散，从而允许对白质（WM）微观结构进行非侵入性投资，它可能有助于诊断和理解白色物质异常异常和延迟的成熟性的病理学。 DTI也已广泛用于肿瘤患者和具有非焦焦点疾病的患者中WM途径的非侵入性追踪。不幸的是，DTI不仅遭受身体运动的痛苦，而且还遭受了随着较高磁场的增加而增加的深刻技术困难。另一方面，较高的磁场将提供更多的信噪比（SNR）。高场运动补偿DTI的主要好处之一就是儿童，因为它们的头大小较小，运动的可能性较高。目的 - 这项为期两年的研究工作的总体目标是改善扩散加权的多发螺旋成像，以在2D和3D扩散张量成像中显着改善。具体而言，该项目的重点是改进螺旋采集方法和相应的重建技术，这些技术减少了扭曲，改善了对运动的免疫力，减少RF沉积并提供更好的空间分辨率。 还特别强调了改善该序列的小儿成像的图像质量。具体目的是：（具体目的＃1）用于开发和优化2D和3D采集的实时螺旋扩散加权MRI的采集和重建方法； （特定目的＃2）为不同的临床应用和运动变体定义了2D和3D的最佳DTI扫描参数。 方法 - 导航器，（前瞻性和回顾性）运动和异位校正校正方案将与增强的平行成像重建算法共同开发和优化，并在模拟和幻影研究中进行优化。健康的儿童（n = 62）和成年人（n = 30）将被招募进行广泛的测试。一系列不同临床问题和运动变体的最佳DTI扫描参数将由经验丰富的神经模具和神经放射学家确定。 The raw k-space data and high-resolution diffusion tensor data will be added to a registry and can be made available to the public to improve image reconstruction algorithms (e.g. off-resonance correction, parallel imaging, diffusion phase navigation, grinding reconstruction), tensor processing (e.g. studying partial volume effects, crossing fibers, complex tract tracing algorithms) and to provide a normal可用于未来试验的成人和儿童的数据库。 意义 - 我们认为，在成功完成该项目后，可以实现DTI的重大改进，这将改善具有各种病理状况的患者的形态评估和道路追踪。 WM和道项目的异常情况可以提供几种攻击白质疾病的病理生理学的关键见解，并进一步了解患有和没有WM疾病的儿童的特定神经发育轨迹。