BackgroundDifferent MR elastography (MRE) systems may produce different stiffness measurements, making direct comparison difficult in multi‐center investigations.PurposeTo assess the repeatability and reproducibility of liver stiffness measured by three typical MRE systems.Study TypeProspective.Population/PhantomsThirty volunteers without liver disease history (20 males, aged 21–28)/5 gel phantoms.Field Strength/Sequence3.0 T United Imaging Healthcare (UIH), 1.5 T Siemens Healthcare, 3.0 T General Electric Healthcare (GE)/Echo planar imaging‐based MRE sequence.AssessmentWave images of volunteers and phantoms were acquired by three MRE systems. Tissue stiffness was evaluated by two observers, while phantom stiffness was assessed automatically by code. The reproducibility across three MRE systems was quantified based on the mean stiffness of each volunteer and phantom.Statistical TestsIntraclass correlation coefficients (ICC), coefficients of variation (CV), and Bland–Altman analyses were used to assess the interobserver reproducibility, the interscan repeatability, and the intersystem reproducibility. Paired t‐tests were performed to assess the interobserver and interscan variation. Friedman tests with Dunn's multiple comparison correction were performed to assess the intersystem variation. P values less than 0.05 indicated significant difference.ResultsThe reproducibility of stiffness measured by the two observers demonstrated consistency with ICC > 0.92, CV < 4.32%, Mean bias < 2.23%, and P > 0.06. The repeatability of measurements obtained using the electromagnetic system for the liver revealed ICC > 0.96, CV < 3.86%, Mean bias < 0.19%, P > 0.90. When considering the range of reproducibility across the three systems for liver evaluations, results ranged with ICCs from 0.70 to 0.87, CVs from 6.46% to 10.99%, and Mean biases between 1.89% and 6.30%. Phantom studies showed similar results. The values of measured stiffness differed across all three systems significantly.Data ConclusionLiver stiffness values measured from different MRE systems can be different, but the measurements across the three MRE systems produced consistent results with excellent reproducibility.Evidence Level1Technical EfficacyStage 2

中文翻译：

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三种肝脏磁共振弹性成像系统的比较研究

背景不同的磁共振弹性成像（MRE）系统可能产生不同的硬度测量结果，使得在多中心研究中直接比较变得困难。目的评估三种典型MRE系统测量的肝脏硬度的重复性和再现性。研究类型前瞻性。人群/模型30名无肝病史的志愿者（20 名男性，年龄 21-28）/5 个凝胶体模。场强/序列3.0 T 联合成像医疗保健 (UIH)、1.5 T 西门子医疗保健、3.0 T 通用电气医疗保健 (GE)/基于 Echo 平面成像的 MRE 序列。志愿者和模型的评估波图像由三个 MRE 系统获取。组织硬度由两名观察者评估，而模型硬度由代码自动评估。根据每个志愿者和体模的平均刚度对三个 MRE 系统的再现性进行量化。统计测试使用组内相关系数 (ICC)、变异系数 (CV) 和 Bland-Altman 分析来评估观察者间的再现性、扫描间的重复性，以及系统间的再现性。配对t‐进行测试以评估观察者间和扫描间差异。进行弗里德曼检验和邓恩多重比较校正来评估系统间的变化。磷值小于 0.05 表示存在显着差异。 结果 两名观察者测量的刚度再现性与 ICC > 0.92、CV < 4.32%、平均偏倚 < 2.23% 一致。磷> 0.06。使用肝脏电磁系统获得的测量结果的重复性显示 ICC > 0.96，CV < 3.86%，平均偏差 < 0.19%，磷> 0.90。当考虑肝脏评估的三个系统的重现性范围时，结果的 ICC 范围为 0.70 至 0.87，CV 范围为 6.46% 至 10.99%，平均偏差范围为 1.89% 至 6.30%。幻影研究显示了类似的结果。所有三个系统的测量硬度值均存在显着差异。数据结论不同 MRE 系统测量的肝脏硬度值可能不同，但三个 MRE 系统的测量结果一致，具有出色的重现性。证据级别 1 技术功效阶段 2