Sorbonne Université, INSERM, CNRS, LIB, Department of Radiology, hôpitaux universitaires Pitié-Salpêtrière - Charles Foix, AP-HP, 47-83, boulevard de l'Hôpital, 75013 Paris, France.
Sorbonne Université, INSERM, CNRS, LIB, Department of Radiology, hôpitaux universitaires Pitié-Salpêtrière - Charles Foix, AP-HP, 47-83, boulevard de l'Hôpital, 75013 Paris, France; Department of Radiology, Yonsei University College of Medicine, Severance Hospital, 50 Yonsei-ro, Sinchon-dong, Seodaemun-gu, Seoul, South Korea.
Diagn Interv Imaging. 2019 Jun;100(6):363-370. doi: 10.1016/j.diii.2019.01.005. Epub 2019 Feb 10.
To assess the variability of liver stiffness measurements using magnetic resonance elastography (MRE) at 1.5T, depending on different approaches of regions of interest (ROIs) drawing.
Fifty consecutive patients with successful liver MRE were included. There were 32 men and 18 women with a mean age of 52±14 (SD) years (range: 20-85 years). MRE was acquired using a gradient recalled-echo MRE sequence. At the level of the portal bifurcation, one observer drawn in the right liver first 3 elliptical ROI and then one free-hand ROI, as large as possible based on the confidence map and the anatomy. Three additional elliptical ROIs were further drawn on the slice above and 3 other on the slice below, for a total of 9 elliptical ROIs. The average value of liver stiffness in the 3 elliptical ROIs of the central slice and the one from the 9 elliptical ROIs were computed. Three liver stiffness values were obtained for each patient from the 3 measurement methods (one free-hand ROI, 3 elliptical ROIs and 9 elliptical ROIs). Inter-method variability was assessed using the intra-class correlation coefficient (ICC) and Bland-Altman analysis.
The variability between the 3 methods was excellent with ICC>0.978 (P<0.0001). The Bland-Altman analysis revealed high agreement between the 3 methods with bias<0.45kPa and limits of agreement<±1.13kPa. The variability was lower when comparing a large free-hand ROI and the 3-elliptical ROIs, than when comparing the 9-elliptical ROIs to one of the other methods.
Our results show that the variability between the 3 methods of ROI drawing and placement is very low.
评估 1.5T 磁共振弹性成像（MRE）测量肝脏硬度的可变性，取决于不同的感兴趣区（ROI）绘制方法。
共纳入 50 例成功进行肝脏 MRE 的患者。其中男 32 例，女 18 例，平均年龄 52±14（SD）岁（范围：20-85 岁）。MRE 使用梯度回波 MRE 序列采集。在门脉分叉水平，一名观察者首先在右肝绘制 3 个椭圆形 ROI，然后根据置信图和解剖结构尽可能绘制一个自由手 ROI。在上方切片上进一步绘制 3 个椭圆形 ROI，在下方切片上再绘制 3 个椭圆形 ROI，总共 9 个椭圆形 ROI。计算中央切片上 3 个椭圆形 ROI 和 9 个椭圆形 ROI 中肝脏硬度的平均值。从 3 种测量方法（1 个自由手 ROI、3 个椭圆形 ROI 和 9 个椭圆形 ROI）中为每位患者获得 3 个肝脏硬度值。使用组内相关系数（ICC）和 Bland-Altman 分析评估方法间的变异性。
3 种方法间的变异性极好，ICC>0.978（P<0.0001）。Bland-Altman 分析显示 3 种方法之间具有高度一致性，偏差<0.45kPa，一致性界限<±1.13kPa。当比较大的自由手 ROI 和 3 个椭圆形 ROI 时，变异性低于将 9 个椭圆形 ROI 与其他方法之一进行比较时的变异性。
我们的结果表明，3 种 ROI 绘制和放置方法之间的变异性非常低。
