Improvements in Spiral MR Imaging

螺旋磁共振成像的改进

• 批准号: 7034694
• 负责人: JEFFREY L. DUERK
• 金额: $ 38.6万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-15 至 2009-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7034694
• 关键词: abdomen; adipose tissue; bioimaging /biomedical imaging; brain imaging /visualization /scanning; clinical research; computer program /software; computer simulation; evaluation /testing; functional magnetic resonance imaging; heart imaging /visualization /scanning; human subject; image enhancement; image processing; magnetic resonance imaging

DESCRIPTION (provided by applicant): Using a state-of-the-art 1.5T MR system, the main goal of the proposed project is to create significant im- provements in spiral MRI via novel techniques that reduce imaging time, improve immunity to motion artifact, and improve off-resonance (and chemical shift) reconstruction so that new and/or improved cardiac, brain and body imaging applications will be enabled. The specific aims are to: (1) improve spiral MR motion artifact immunity by developing efficient reductions in spiral MRI acquisition time through parallel imaging methods and reconstruction (e.g., SENSE, GRAPPA, conjugate gradient) at high acceleration; (2) develop new rapid off-resonance correction techniques with improved performance and reduced computation time when compared to conventional frequency segmented methods, (3) create robust spiral fat/water separation methods that prevent off-resonance blurring and provide superior performance and reduced acquisition time when compared to spatial spectral techniques, and, (4) develop methodologies for Pareto-optimal /(-space trajectory design based on minimizing time, aliasing energy, flow sensitivity, off-resonance blurring and/or other image quality measurements. Our project will show that use of new spiral acquisition, new post-processing methods and new trajectory de- sign techniques using/(-space and/or image data can reduce imaging time and significantly improve cardiac, brain and abdominal imaging. Preliminary results show that significant improvements in motion immunity through parallel imaging are possible. Significant work remains to explore improvements in reconstruction algorithms, amount of acceleration, and reliability. Off-resonance computational burden can be reduced by using a block re- gional correction method. For example, further improvements in performance and speed will explore use of re- gional information to control the computational block size. Our fat suppression methods will give rise to reductions in scan time by up to a factor of 2-4X with superior performance as compared to commonly used spatial spectral approaches; the efficiency/robustness of 2pt and 3pt Spiral Dixon methods (at equal scan time) are explored. These alone will enable improved abdominal and cardiac imaging when compared to conventional rectilinear or spiral methods. Uniquely, our advanced non-rectilinear trajectory, design method is that the inter-relationship be- tween off-resonance, motion and kappa-space sampling density effects are formally linked to image domain artifacts, thereby enabling unique waveform parameterizations and formal optimization to create superior trajectories (and hence better images) than those designed conventionally. We believe successful attainment of these aims will give rise to significant improvements in spiral MR and hence greater utilization of this important MR method.

描述（由申请人提供）：使用最先进的 1.5T MR 系统，拟议项目的主要目标是通过减少成像时间、提高对运动伪影的免疫力和改善非共振（和化学位移）重建的新技术来显着改进螺旋 MRI，从而实现新的和/或改进的心脏、大脑和身体成像应用。具体目标是：（1）通过高加速下的并行成像方法和重建（例如，SENSE、GRAPPA、共轭梯度）有效减少螺旋 MRI 采集时间，从而提高螺旋 MR 运动伪影免疫力； (2) 开发新的快速偏共振校正技术，与传统的频率分段方法相比，具有改进的性能并减少计算时间，(3) 创建稳健的螺旋脂肪/水分离方法，与空间谱技术相比，防止偏共振模糊并提供卓越的性能并减少采集时间，(4) 开发基于最小化的帕累托最优/(-空间轨迹设计) 时间、混叠能量、流动灵敏度、偏共振模糊和/或其他图像质量测量。 我们的项目将表明，使用新的螺旋采集、新的后处理方法和使用/(-空间和/或图像数据的新轨迹设计技术可以减少成像时间并显着改善心脏、大脑和腹部成像。初步结果表明，通过并行成像显着改善运动免疫是可能的。探索重建算法、加速量和可靠性方面的改进仍有大量工作要做。 通过使用块区域校正方法可以减少偏共振的计算负担。例如，性能和速度的进一步改进将探索使用区域信息来控制计算块大小。与常用的空间光谱方法相比，我们的脂肪抑制方法可将扫描时间缩短 2-4 倍，且性能优越； 2pt 和 3pt 螺旋 Dixon 方法的效率/鲁棒性 （在相同的扫描时间）进行探索。与传统的直线或螺旋方法相比，仅这些就可以改善腹部和心脏成像。独特的是，我们先进的非直线轨迹设计方法是将非共振、运动和卡帕空间采样密度效应之间的相互关系正式链接到图像域伪影，从而实现独特的波形参数化和 形式优化可创建比传统设计更出色的轨迹（从而获得更好的图像）。我们相信，成功实现这些目标将带来螺旋磁共振的显着改进，从而更好地利用这一重要的磁共振方法。