Wide Field MR Microscopy using Integrated Gradient and RF Array Coils

描述（由申请人提供）：EBRG提案的目的是开发和演示一种新的高分辨率MR成像技术，即宽场磁共振显微镜（MRM）。MR显微镜，被大多数定义为在任何维度上具有100微米或更小的分辨率的成像，将成为一种宝贵的工具，因为医学的未来显然朝着细胞水平发展，因为它能够以高分辨率非侵入性地探测体内和体外组织，同时提供MRI的许多对比机制。在提供组织微环境的高分辨率成像的同时，传统的MRM通过使用被设计为提高信噪比的小射频线圈而被限制在非常小的视场，或者可替代地，通过以高分辨率在大视场上编码MR图像所需的时间而被限制在非常小的视场。这项工作提出了一种宽场MR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，从而能够以大大减少的成像时间在大视场上实现高分辨率MRI。本项目中开发的技术进步是集成梯度和RF阵列线圈，为用户提供极高分辨率成像或极快速成像（分辨率降低）之间的选择。两者都是通过使用64个或更多对准的接收器线圈的阵列来使成像过程并行化，从而减少对基于梯度的相位编码的依赖。高速数字接收器使得视场能够沿着平行线圈的长轴沿着增加，而平行成像在相反方向上增加视场。将优化平面梯度线圈，并将独立的第四梯度通道集成到MR扫描仪中，以补偿由接收线圈产生的远距离相关相移，该相移降低了高加速MR成像中的信号强度。最后，一个对宽场MR显微镜潜力感兴趣的合作者团队，包括两名MR显微镜专家和三名临床科学家，将提供不同类型的组织样本，用于测试和评估新方法。如果成功，该项目将使MR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领域。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，可能低至细胞分辨率。该项目的目标是开发一种新技术，宽场MR显微镜，它将并行成像与独特的相位校正梯度相结合，以大大减少成像时间，在大视场范围内实现高分辨率MRI。这种技术是通过一种新的探头设计，这将提供执行MR显微镜的能力，无论是极高的空间分辨率或极高的时间分辨率在相同的视场。

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.