Departments of Biomedical Engineering and Radiology, Columbia University, New York, New York.
Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
NMR Biomed. 2021 May;34(5):e4350. doi: 10.1002/nbm.4350. Epub 2020 Jun 28.
Magnetic resonance spectroscopy (MRS) and spectroscopic imaging (MRSI) allow the chemical analysis of physiological processes in vivo and provide powerful tools in the life sciences and for clinical diagnostics. Excellent homogeneity of the static B magnetic field over the object of interest is essential for achieving high-quality spectral results and quantitative metabolic measurements. The experimental minimization of B variation is performed in a process called B shimming. In this article, we summarize the concepts of B field shimming using spherical harmonic shimming techniques, specific strategies for B homogenization and crucial factors to consider for implementation and use in both brain and body. In addition, experts' recommendations are provided for minimum requirements for B shim hardware and evaluation criteria for the primary outcome of adequate B shimming for MRS and MRSI, such as the water spectroscopic linewidth.
磁共振波谱（MRS）和波谱成像（MRSI）允许对体内生理过程进行化学分析，并为生命科学和临床诊断提供强大的工具。在感兴趣的物体上获得高质量的光谱结果和定量代谢测量，静态 B 磁场的优异均匀性是必不可少的。通过称为 B 调谐的过程来最小化 B 变化。在本文中，我们总结了使用球谐调谐技术的 B 场调谐概念，用于 B 均匀化的特定策略以及在脑和体中实施和使用时需要考虑的关键因素。此外，还为 B 调谐硬件的最低要求以及 MRS 和 MRSI 的适当 B 调谐的主要结果（例如水光谱线宽）的评估标准提供了专家建议。
