MULTIPLEXED ECHO PLANAR IMAGING FOR NEUROSCIENCES

描述（由申请人提供）：MRI是一种经过验证的非侵入性技术，可以制作高分辨率的大脑图像。回声平面成像（Echo planar imaging， EPI）以其快速的成像速度和独特的成像机制，成为神经科学领域应用最广泛的MRI技术。EPI结合扩散敏感梯度脉冲提供了轴突纤维的三维可视化，揭示了人类大脑的连接解剖。EPI也几乎专门用于功能性磁共振成像（fMRI），因为它对大脑不同区域的“血氧水平依赖”（BOLD）对比变化具有极高的敏感性，可以显示神经元活动图。我们建议开发一系列高效的新EPI序列，用于扩散和功能磁共振成像，提供几倍快的大脑成像。这种新的快速成像技术通过在单次回波序列中复用多个图像来工作，从每个信号序列中产生多个图像，而不是单个EPI图像，而在正常的EPI脉冲序列中只产生单个图像。新的多路EPI成像序列将在很大程度上取代Peter Mansfield于1978年发明的原始EPI序列，该序列迄今已用于所有神经科学和临床脑成像。这些多路EPI技术的可用性将使研究人员和临床医生能够在扫描时间从25分钟减少到8或12分钟的扫描时间内进行高角分辨率扩散成像（HARDI），并且这些扫描时间对患者和研究对象来说都更容易忍受。多路复用的EPI扫描速度可以提高许多倍，或者用于提供更多更薄的图像，以获得更高的分辨率并减少伪影。整个大脑的扫描时间大大加快，将使7特斯拉和3特斯拉的功能磁共振成像的新实验成为可能。该序列将在加州大学伯克利分校和旧金山分校的3T、明尼苏达大学的7T和10.5T的MRI扫描仪上进行设计、实施和评估。一旦multiexed EPI序列得到充分评估和优化，它将成为基础和临床神经科学研究以及临床诊断成像的有用工具。

DESCRIPTION (provided by applicant): MRI is a proven non-invasive technique that makes high resolution image of the brain. Echo planar imaging (EPI) is the most widely used MRI technique used for neurosciences due to its extremely fast imaging speed and unique contrast mechanisms. EPI combined with diffusion sensitive gradient pulses provides 3D visualization of axonal fibers, which reveals the connectional anatomy of the human brain. EPI is also nearly exclusively used for functional MRI (fMRI) given its extremely high sensitivity to changes in "blood oxygen level dependent" (BOLD) contrast in different regions of the brain, revealing maps of neuronal activity. We are proposing to develop a family of highly efficient new EPI sequences for diffusion and fMRI providing several times faster imaging of the brain. This new faster imaging technique works by multiplexing several images within the single-shot echo train, to produce several images instead of a single EPI image from a each train of signals, whereas only a single image is produced in the normal EPI pulse sequence. The new Multiplexed EPI imaging sequence will largely replace the use of the original EPI sequence invented by Peter Mansfield in 1978 that to date has been used for all neuroscience and clinical brain imaging. The availability of these Multiplexed EPI techniques will give researchers and clinicians the capability of performing high angular resolution diffusion imaging (HARDI) in scan times reduced from 25 minutes to 8 or 12 minutes scans and these scan times will be more tolerable by both patients and research subjects. The multiplexed EPI can scan many times faster or instead be used to provide more images that are thinner for higher resolution and reduced artifacts. The greatly accelerated scan times of the whole brain will enable new experiments in functional MRI at 7 Tesla and 3 Tesla. The sequence will be designed, implemented and evaluated on MRI scanners operating at 3T at University of California Berkeley and San Francisco and at 7T and 10.5T at University of Minnesota. Once the Multiplexed EPI sequence is fully evaluated and optimized, it will be made into a useful tool for basic and clinical neuroscience research, and for clinical diagnostic imaging.