Objectives

To compare biliary stricture severity on magnetic resonance cholangiopancreatography (MRCP), magnetic resonance elastography (MRE), and vibration-controlled transient elastography (VCTE) liver stiffness (LS) for evaluation of risk stratification and prognostication in primary sclerosing cholangitis (PSC).

Materials and methods

Eighty-seven patients (31–61 years; 34 female/53 male) prospectively underwent biochemical testing, VCTE, MRCP, and MRE between January 2014 and July 2016. Correlation between the MRCP grading of PSC based on biliary stricture severity, LS on MRE and VCTE, and the Mayo Risk Score as well as the Amsterdam Oxford Prognostic Index (AOPI) were evaluated and compared. Stricture severity was classified according to previous classification systems based on ERCP. Spearman’s correlation and Kruskal-Wallis tests were performed.

Results

MRE-LS and intrahepatic stricture severity combined demonstrated higher discriminatory ability among risk categories based on Mayo Risk Score (AUROC = 0.8). MRE-LS alone demonstrated excellent discriminatory ability among risk categories based on AOPI using cutoffs of 1 and 2.7 and was superior to intrahepatic stricture severity (AUROC = 0.9, AUROC = 0.6–0.7). There was a weak correlation between intrahepatic stricture severity and MRE-LS (rho = 0.3; p = 0.011). VCTE-LS values were not correlated with stricture severity and were noncontributory to differentiate patients across risk groups. Intrahepatic stricture severity alone was a poor discriminator of advanced liver fibrosis on MRE (AUROC = 0.7); however, combining intra- and extrahepatic stricture severity and controlling for cholestasis and disease duration improved results (AUROC = 0.9).

Conclusion

This study demonstrates a significant discriminatory ability of LS values on MRE to distinguish between early to moderate and advanced liver fibrosis. LS values on MRE may add value to risk prognostication and further studies including clinical outcomes are needed.

Key Points

• Risk stratification was excellent for liver stiffness measurements on MRE and poor for VCTE and biliary stricture severity.

• Risk stratification was further improved when liver stiffness measured on MRE was combined with intrahepatic and extrahepatic stricture severity and indicators of cholestasis were controlled for.

• Liver stiffness measurements on MRE correlated with prognostic scores better than measurements performed on VCTE.

目标

为了比较胆道狭窄的严重程度，应评估磁共振胆管胰腺造影（MRCP），磁共振弹性成像（MRE）和振动控制的瞬时弹性成像（VCTE）的肝脏硬度（LS），以评估原发性硬化性胆管炎（PSC）的危险分层和预后。

材料和方法

在2014年1月至2016年7月之间，预期对87例患者（31-61岁； 34位女性/ 53位男性）进行了生化测试，VCTE，MRCP和MRE。基于胆道狭窄严重程度的PSC MRCP分级与MRE的LS之间存在相关性和VCTE，以及梅奥风险评分和阿姆斯特丹牛津大学预后指数（AOPI）进行了评估和比较。严格程度是根据以前基于ERCP的分类系统进行分类的。进行了Spearman相关性和Kruskal-Wallis检验。

结果

根据Mayo风险评分（AUROC = 0.8），MRE-LS和肝内狭窄严重程度的组合显示出较高的区分风险的能力。单独的MRE-LS在AOPI的基础上使用1和2.7的临界值表现出出色的区分风险的能力，并且优于肝内狭窄的严重程度（AUROC = 0.9，AUROC = 0.6-0.7）。肝内狭窄严重程度与MRE-LS之间的相关性较弱（rho = 0.3; p = 0.011）。VCTE-LS值与狭窄严重程度无关，并且不能区分不同风险组的患者。仅肝内狭窄严重程度不足以区分MRE（AUROC = 0.7）晚期肝纤维化。然而，结合肝内和肝外狭窄的严重程度并控制胆汁淤积和疾病持续时间可改善结果（AUROC = 0.9）。

结论

这项研究证明了MRE的LS值具有明显的区分能力，可以区分早期，中度和晚期肝纤维化。MRE上的LS值可能会增加风险预后的价值，需要进一步的研究，包括临床结果。

关键点

•对于MRE的肝硬度测量，风险分层非常好，而VCTE和胆道狭窄严重程度则风险分层很差。

•通过将MRE测得的肝脏僵硬与肝内和肝外狭窄的严重程度相结合并控制胆汁淤积的指标，风险分层得到进一步改善。

•与VCTE相比，在MRE上进行的肝硬度测量与预后评分相关性更好。