Abstract：
BACKGROUND: Different MR elastography (MRE) systems may produce different stiffness measurements, making direct comparison difficult in multi-center investigations.
OBJECTIVE: To assess the repeatability and reproducibility of liver stiffness measured by three typical MRE systems.
METHODS: Prospective.
UNASSIGNED: Thirty volunteers without liver disease history (20 males, aged 21-28)/5 gel phantoms.
UNASSIGNED: 3.0 T United Imaging Healthcare (UIH), 1.5 T Siemens Healthcare, 3.0 T General Electric Healthcare (GE)/Echo planar imaging-based MRE sequence.
RESULTS: Wave 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.
METHODS: Intraclass 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.
RESULTS: The 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.
CONCLUSIONS: Liver stiffness values measured from different MRE systems can be different, but the measurements across the three MRE systems produced consistent results with excellent reproducibility.
METHODS: 1 TECHNICAL EFFICACY: Stage 2.
OBJECTIVE: To assess the repeatability and reproducibility of liver stiffness measured by three typical MRE systems.
METHODS: Prospective.
UNASSIGNED: Thirty volunteers without liver disease history (20 males, aged 21-28)/5 gel phantoms.
UNASSIGNED: 3.0 T United Imaging Healthcare (UIH), 1.5 T Siemens Healthcare, 3.0 T General Electric Healthcare (GE)/Echo planar imaging-based MRE sequence.
RESULTS: Wave 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.
METHODS: Intraclass 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.
RESULTS: The 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.
CONCLUSIONS: Liver stiffness values measured from different MRE systems can be different, but the measurements across the three MRE systems produced consistent results with excellent reproducibility.
METHODS: 1 TECHNICAL EFFICACY: Stage 2.
摘要：
背景：不同的MR弹性成像（MRE）系统可能会产生不同的刚度测量，在多中心调查中难以直接比较。
目的：评估通过三种典型的MRE系统测量的肝脏硬度的可重复性和可重复性。
方法：前瞻性。
■30名无肝病史的志愿者（20名男性，21-28岁）/5个凝胶体模。
■3.0T联合成像医疗保健（UIH），1.5T西门子医疗，3.0T通用电气医疗(GE)/基于回波平面成像的MRE序列。
结果：通过三个MRE系统获取了志愿者和体模的波形图像。由两名观察者评估组织硬度，而体模刚度是通过代码自动评估的。基于每个志愿者和体模的平均刚度来量化三个MRE系统的再现性。
方法：组内相关系数(ICC)，变异系数(CV)，和Bland-Altman分析用于评估观察者间的可重复性，间扫描可重复性，和系统间的可重复性。进行配对t检验以评估观察者间和扫描间的变化。使用Dunn的多重比较校正进行Friedman测试以评估系统间变化。P值小于0.05表明差异显著。
结果：两位观察者测量的刚度的再现性证明与ICC>0.92，CV<4.32％，平均偏差<2.23%，P>0.06。使用肝脏电磁系统获得的测量结果的可重复性显示ICC>0.96，CV<3.86％，平均偏差<0.19%，P>0.90。当考虑肝脏评估的三个系统的可重复性范围时，结果范围为ICC从0.70到0.87，CV从6.46%到10.99%，平均偏差在1.89%至6.30%之间。幻影研究显示了类似的结果。在所有三个系统中，测得的刚度值显着不同。
结论：从不同MRE系统测得的肝脏硬度值可能不同，但三个MRE系统的测量结果一致,重现性极佳.
方法：1技术效果：阶段2。
目的：评估通过三种典型的MRE系统测量的肝脏硬度的可重复性和可重复性。
方法：前瞻性。
■30名无肝病史的志愿者（20名男性，21-28岁）/5个凝胶体模。
■3.0T联合成像医疗保健（UIH），1.5T西门子医疗，3.0T通用电气医疗(GE)/基于回波平面成像的MRE序列。
结果：通过三个MRE系统获取了志愿者和体模的波形图像。由两名观察者评估组织硬度，而体模刚度是通过代码自动评估的。基于每个志愿者和体模的平均刚度来量化三个MRE系统的再现性。
方法：组内相关系数(ICC)，变异系数(CV)，和Bland-Altman分析用于评估观察者间的可重复性，间扫描可重复性，和系统间的可重复性。进行配对t检验以评估观察者间和扫描间的变化。使用Dunn的多重比较校正进行Friedman测试以评估系统间变化。P值小于0.05表明差异显著。
结果：两位观察者测量的刚度的再现性证明与ICC>0.92，CV<4.32％，平均偏差<2.23%，P>0.06。使用肝脏电磁系统获得的测量结果的可重复性显示ICC>0.96，CV<3.86％，平均偏差<0.19%，P>0.90。当考虑肝脏评估的三个系统的可重复性范围时，结果范围为ICC从0.70到0.87，CV从6.46%到10.99%，平均偏差在1.89%至6.30%之间。幻影研究显示了类似的结果。在所有三个系统中，测得的刚度值显着不同。
结论：从不同MRE系统测得的肝脏硬度值可能不同，但三个MRE系统的测量结果一致,重现性极佳.
方法：1技术效果：阶段2。
