Wide Field MR Microscopy using Integrated Gradient and RF Array Coils

描述（由申请人提供）：本EBRG提案的目标是开发和演示一种新的高分辨率磁共振成像技术，宽视场磁共振显微镜（MRM）。磁共振显微镜被大多数人定义为在任何维度上以100微米或更小的分辨率成像，由于其能够以高分辨率无创探测体内和体外组织，同时提供MRI的许多对比机制，它将成为未来医学明确向细胞水平发展的宝贵工具。在提供组织微环境的高分辨率成像的同时，传统的MRM被限制在一个非常小的视场内，因为使用小型射频线圈来提高信噪比，或者，在高分辨率的大视场上编码MR图像所需的时间。本工作提出了一种宽视场磁共振显微镜的方法。该技术结合了并行成像和独特的相位校正梯度通道，可以在大大减少成像时间的情况下在大视场上实现高分辨率MRI。在这个项目中要开发的技术进步是一个集成的梯度和射频阵列线圈，它为用户提供了极高分辨率成像或极快成像（降低分辨率）之间的选择。两者都是通过使用64个或更多对齐的接收器线圈阵列来并行成像过程，减少对基于梯度的相位编码的依赖。高速数字接收机使视场沿平行线圈的长轴方向增加，而平行成像则在相反方向增加视场。将优化平面梯度线圈，并将独立的第四个梯度通道集成到MR扫描仪中，以补偿由接收线圈传递的距离相关相移，这些相移会降低高加速MR成像中的信号强度。最后，一组对宽视场磁共振显微镜的潜力感兴趣的合作者，包括两位磁共振显微镜专家和三位临床科学家，将提供不同类型的组织样本来测试和评估新方法。如果成功，该项目将使磁共振显微镜具有比以前更宽的视角和更高的速度，将其扩展到更广泛的应用范围。磁共振显微镜将临床磁共振成像的能力扩展到极高的分辨率，有可能降低到细胞分辨率。该项目的目标是开发一种新技术，即宽视场磁共振显微镜，该技术将平行成像与独特的相位校正梯度相结合，从而在大大减少成像时间的情况下，在大视场上实现高分辨率MRI。这项技术是由一种新的探针设计实现的，它将提供在相同视场上以极高的空间分辨率或极高的时间分辨率执行MR显微镜的能力。

DESCRIPTION (provided by applicant): The objective of this EBRG proposal is to develop and demonstrate a new high resolution MR imaging technique, wide-field magnetic resonance microscopy (MRM). MR microscopy, defined by most as imaging with a resolution of 100 microns or less in any dimension, will become an invaluable tool as the future of medicine clearly moves towards the cellular level due to its ability to non-invasively probe in vivo and in vitro tissue with high-resolution while providing the many contrast mechanisms of MRI. While providing high resolution imaging of the tissue microenvironment, conventional MRM is limited to a very small field-of-view by the use of small radiofrequency coils designed to improve the signal-to-noise ratio, or, alternatively, by the time required to encode the MR image over a large field-of-view at high-resolutions. This work proposes a method for wide field MR microscopy. This technique combines parallel imaging and a unique phase correcting gradient channel to enable high resolution MRI over a large field-of-view at greatly reduced imaging times. The technological advancement to be developed in this project is an integrated gradient and RF array coil which provides the user a choice between extremely high-resolution imaging or extremely fast imaging (at reduced resolution). Both are enabled by using an array of 64 or more aligned receiver coils to parallelize the imaging process, reducing reliance on gradient-based phase encoding. High- speed digital receivers enable the field-of-view to be increased along the long-axis of the parallel coils, while parallel imaging increases the field-of-view in the opposite direction. A planar gradient coil will be optimized and an independent, fourth gradient channel integrated into the MR scanner to compensate for distant dependent phase shifts imparted by the receive coils which reduce signal strength in highly accelerated MR imaging. Finally, a team of collaborators interested in the potential of wide-field MR microscopy, including two experts in MR microscopy and three clinical scientists, will provide tissue samples of different types for testing and assessing the new method. If successful, this project will enable MR microscopy with wider perspective and higher speed than previously possible, extending it into a broader range of applications. Magnetic resonance microscopy extends the power of clinical magnetic resonance imaging to extremely high resolutions, potentially down to cellular resolution. The goal of this project is to develop a new technique, wide field MR microscopy, which combines parallel imaging with a unique phase correcting gradient to enable high resolution MRI over a large field of view at greatly reduced imaging times. This technique is enabled by a new probe design which will provide the ability to perform MR microscopy at either extremely high spatial resolution or extremely high temporal resolution over the same field-of-view.