Institute of Neuroscience and Medicine - 4, Forschungszentrum Juelich, Juelich, Germany.
Institute of Neuroscience and Medicine - 4, Forschungszentrum Juelich, Juelich, Germany.
Magn Reson Imaging. 2020 Oct;72:103-116. doi: 10.1016/j.mri.2020.07.003. Epub 2020 Jul 9.
With the increasing availability of ultra-high field MRI systems, studying non-proton nuclei (X-nuclei), such as Na and P has received great interest. X-nuclei are able to provide insight into important cellular processes and energy metabolism in tissues and by monitoring these nuclei closely it is possible to establish links to pathological conditions and neurodegenerative diseases. In order to investigate X-nuclei, a well-designed radiofrequency (RF) system with a multi-tuned RF coil is required. However, as the intrinsic sensitivity of non-proton nuclei is lower compared to H, it is important to ensure that the signal-to-noise ratio (SNR) of the X-nuclei is as high as possible. This review aims to give a comprehensive overview of previous efforts, with particular focus on the design concept of multi-tuned coils, predominantly for brain applications. In order to guide the readers, the main body of the review is categorised into two parts: state-of-the art according to the single or multiple design structures and emerging technologies. A more detailed description is given in each subsection relating to the specific design approaches of, mostly, double-tuned coils, including using traps, PIN-diodes, nested and metamaterial, together with explanations of their novelties, optimal solutions and trade-offs.
随着超高场 MRI 系统的日益普及，研究非质子核（X 核），如 Na 和 P，引起了极大的兴趣。X 核能够深入了解组织中的重要细胞过程和能量代谢，通过密切监测这些核，有可能建立与病理状况和神经退行性疾病的联系。为了研究 X 核，需要一个设计良好的射频（RF）系统，带有多调谐 RF 线圈。然而，由于与 H 相比，非质子核的固有灵敏度较低，因此确保 X 核的信噪比（SNR）尽可能高是很重要的。本综述旨在全面概述以前的研究工作，特别关注多调谐线圈的设计概念，主要用于脑应用。为了指导读者，综述的主体分为两部分：根据单一或多个设计结构的最新进展和新兴技术。在每个与双调谐线圈的具体设计方法相关的子部分中，给出了更详细的描述，包括使用陷阱、PIN 二极管、嵌套和超材料，以及对它们的新颖性、最佳解决方案和权衡的解释。
