Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, the Netherlands.
Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, the Netherlands; Department of Radiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, the Netherlands.
Neuroimage. 2021 Feb 1;226:117561. doi: 10.1016/j.neuroimage.2020.117561. Epub 2020 Nov 12.
Currently, multiple sclerosis is treated with anti-inflammatory therapies, but these treatments lack efficacy in progressive disease. New treatment strategies aim to repair myelin damage and efficacy evaluation of such new therapies would benefit from validated myelin imaging techniques. Several MRI methods for quantification of myelin density are available now. This systematic review aims to analyse the performance of these MRI methods.
Studies comparing myelin quantification by MRI with histology, the current gold standard, or assessing reproducibility were retrieved from PubMed/MEDLINE and Embase (until December 2019). Included studies assessed both myelin histology and MRI quantitatively. Correlation or variance measurements were extracted from the studies. Non-parametric tests were used to analyse differences in study methodologies.
The search yielded 1348 unique articles. Twenty-two animal studies and 13 human studies correlated myelin MRI with histology. Eighteen clinical studies analysed the reproducibility. Overall bias risk was low or unclear. All MRI methods performed comparably, with a mean correlation between MRI and histology of R=0.54 (SD=0.30) for animal studies, and R=0.54 (SD=0.18) for human studies. Reproducibility for the MRI methods was good (ICC=0.75-0.93, R=0.90-0.98, COV=1.3-27%), except for MTR (ICC=0.05-0.51).
Overall, MRI-based myelin imaging methods show a fairly good correlation with histology and a good reproducibility. However, the amount of validation data is too limited and the variability in performance between studies is too large to select the optimal MRI method for myelin quantification yet.
目前，多发性硬化症采用抗炎疗法治疗，但这些治疗方法在进展性疾病中疗效欠佳。新的治疗策略旨在修复髓鞘损伤，而此类新疗法的疗效评估将受益于经过验证的髓鞘成像技术。目前有多种用于定量测量髓鞘密度的 MRI 方法。本系统评价旨在分析这些 MRI 方法的性能。
我们从 PubMed/MEDLINE 和 Embase（截至 2019 年 12 月）检索了比较 MRI 定量测量髓鞘与组织学（当前的金标准）或评估可重复性的研究。纳入的研究同时评估了髓鞘的组织学和 MRI 定量测量。从研究中提取相关性或方差测量值。使用非参数检验分析研究方法学的差异。
搜索共得到 1348 篇独特的文章。22 项动物研究和 13 项人类研究将 MRI 定量测量髓鞘与组织学进行了比较。18 项临床研究分析了可重复性。总体偏倚风险为低或不明确。所有 MRI 方法的表现均相当，动物研究中 MRI 与组织学之间的平均相关性为 R=0.54（SD=0.30），人类研究中为 R=0.54（SD=0.18）。MRI 方法的可重复性较好（ICC=0.75-0.93，R=0.90-0.98，COV=1.3-27%），除了 MTR（ICC=0.05-0.51）。
总体而言，基于 MRI 的髓鞘成像方法与组织学具有相当好的相关性和较好的可重复性。但是，验证数据的数量非常有限，并且研究之间的性能差异很大，因此尚未能够选择用于髓鞘定量的最佳 MRI 方法。
