Sodium is an essential ion that plays a central role in many physiological processes including the transmembrane electrochemical gradient and the maintenance of the body’s homeostasis. Due to the crucial role of sodium in the human body, the sodium nucleus is a promising candidate for non-invasively assessing (patho-)physiological changes. Almost 10 years ago, Madelin et al. provided a comprehensive review of methods and applications of sodium (²³Na) MRI (Madelin et al., 2014) [1]. More recent review articles have focused mainly on specific applications of ²³Na MRI. For example, several articles covered ²³Na MRI applications for diseases such as osteoarthritis (Zbyn et al., 2016, Zaric et al., 2020) [[2], [3]], multiple sclerosis (Petracca et al., 2016, Huhn et al., 2019) [[4], [5]] and brain tumors (Schepkin, 2016) [6], or for imaging certain organs such as the kidneys (Zollner et al., 2016) [7], the brain (Shah et al., 2016, Thulborn et al., 2018) [[8], [9]], and the heart (Bottomley, 2016) [10]. Other articles have reviewed technical developments such as radiofrequency (RF) coils for ²³Na MRI (Wiggins et al., 2016, Bangerter et al., 2016) [[11], [12]], pulse sequences (Konstandin et al., 2014) [13], image reconstruction methods (Chen et al., 2021) [14], and interleaved/simultaneous imaging techniques (Lopez Kolkovsky et al., 2022) [15]. In addition, ²³Na MRI topics have been covered in review articles with broader topics such as multinuclear MRI or ultra-high-field MRI (Niesporek et al., 2019, Hu et al., 2019, Ladd et al., 2018) [[16], [17], [18]].

During the past decade, various research groups have continued working on technical improvements to sodium MRI and have investigated its potential to serve as a diagnostic and prognostic tool. Clinical research applications of ²³Na MRI have covered a broad spectrum of diseases, mainly focusing on the brain, cartilage, and skeletal muscle (see Fig. 1). In this article, we aim to provide a comprehensive summary of methodological and hardware developments, as well as a review of various clinical research applications of sodium (²³Na) MRI in the last decade (i.e., published from the beginning of 2013 to the end of 2022).

钠是一种必需离子，在许多生理过程中发挥着核心作用，包括跨膜电化学梯度和维持人体稳态。由于钠在人体中的关键作用，钠核是无创评估（病理）生理变化的有希望的候选者。大约 10 年前，Madelin 等人。对钠 ( ²³ Na) MRI 的方法和应用进行了全面综述（Madelin 等人，2014 年）[ 1 ]。最近的评论文章主要集中于²³ Na MRI 的具体应用。例如，几篇文章涵盖了²³ Na MRI 在骨关节炎等疾病中的应用（Zbyn 等人，2016 年，Zaric 等人，2020 年）[ [2] ， [3] ]、多发性硬化症（Petracca 等人，2016 年） Huhn et al., 2019) [ [4] , [5] ] 和脑肿瘤 (Schepkin, 2016) [ 6 ]，或用于对肾脏等某些器官进行成像 (Zollner et al., 2016) [ 7 ]，大脑（Shah 等人，2016，Thulborn 等人，2018）[ [8] ， [9] ]，和心脏（Bottomley，2016）[ 10 ]。其他文章回顾了技术发展，例如用于²³ Na MRI 的射频 (RF) 线圈（Wiggins 等人，2016 年、Bangerter 等人，2016 年）[ [11] 、 [12] ]、脉冲序列（Konstandin 等人， 2014）[ 13 ]，图像重建方法（Chen 等人，2021）[ 14 ]，以及交错/同步成像技术（Lopez Kolkovsky 等人，2022）[ 15 ]。 此外，多核 MRI 或超高场 MRI 等更广泛主题的评论文章涵盖了^{23 个}Na MRI 主题（Niesporek 等人，2019；Hu 等人，2019；Ladd 等人，2018）[ [16] 、 [17] 、 [18] ]。

在过去的十年中，各个研究小组继续致力于钠 MRI 的技术改进，并研究了其作为诊断和预后工具的潜力。 ²³ Na MRI的临床研究应用涵盖了广泛的疾病，主要集中在大脑、软骨和骨骼肌（见图1 ）。在本文中，我们旨在提供方法学和硬件发展的全面总结，以及过去十年（即从2013年初发表到年底）钠（ ²³ Na）MRI各种临床研究应用的回顾2022 年）。