A Quantitative Magnetic Resonance Cholangiopancreatography Metric of Intrahepatic Biliary Dilatation Severity Detects High‐Risk Primary Sclerosing Cholangitis

Abstract

Magnetic resonance imaging with magnetic resonance cholangiopancreatography (MRI‐MRCP) in primary sclerosing cholangitis (PSC) is currently based on qualitative assessment and has high interobserver variability. We investigated the utility and performance of quantitative metrics derived from a three‐dimensional biliary analysis tool in adult patients with PSC. MRI‐MRCP, blood‐based biomarkers, and FibroScan were prospectively performed in 80 participants with large‐duct PSC and 20 healthy participants. Quantitative analysis was performed using MRCP+ (Perspectum Ltd., United Kingdom), and qualitative reads were performed by radiologists. Inter‐reader agreements were compared. Patients were classified into high risk or low risk for disease progression, using Mayo risk score (MRS), Amsterdam‐Oxford model (AOM), upper limit of normal (ULN) alkaline phosphatase (ALP), disease distribution, and presence of dominant stricture. Performance of noninvasive tools was assessed using binomial logistic regressions and receiver operating characteristic curve analyses. Quantitative biliary metrics performed well to distinguish abnormal from normal bile ducts (P < 0.0001). Interobserver agreements for MRCP+ dilatation metrics (intraclass correlation coefficient, 0.90‐0.96) were superior to modified Amsterdam intrahepatic stricture severity score (κ = 0.74) and Anali score (κ = 0.38). MRCP+ intrahepatic dilatation severity showed excellent performance to classify patients into high‐risk and low‐risk groups, using predictors of disease severity as the reference (MRS, P < 0.0001; AOM, P = 0.0017; 2.2 × ULN ALP, P = 0.0007; 1.5 × ULN ALP, P = 0.0225; extrahepatic disease, P = 0.0331; dominant stricture, P = 0.0019). MRCP+ intrahepatic dilatation severity was an independent predictor of MRS >0 (odds ratio, 31.3; P = 0.035) in the multivariate analysis. Conclusion: Intrahepatic biliary dilatation severity calculated using MRCP+ is elevated in patients with high‐risk PSC and may be used as an adjunct for risk stratification in PSC. This exploratory study has provided the groundwork for examining the utility of novel quantitative biliary metrics in multicenter studies.

Quantitative magnetic resonance cholangiopancreatography metrics are associated with disease severity and outcomes in people with primary sclerosing cholangitis

“…Indeed, due to its repeatability and reproducibility [14], MRCP+, could provide useful supporting clinically relevant information to radiologists and clinicians concerning the need of further treatments and monitoring response to therapy. MRCP+ could also overcome the poor to moderate inter-reader agreement of the ANALI scores that was recently suggested [16,23]. Regarding the feasibility of the MRCP+, in our cohort we observed that 4.2% of cases were excluded due to low data quality (e.g.…”

“…Similarly, Selvaraj et al recently reported that the volume of the whole biliary tree was not correlated with cholestatic indices, LSM, ELF and prognostic scores except for a moderate correlation with the Amsterdam-Oxford score [16]. On the other hand, when the analysis was limited to the intrahepatic biliary tree volume, several correlations with cholestatic indices and prognostic scores were reported [16]. We can argue about the lack of association between the biliary tree volume and adverse outcome and we may speculate that this apparently conflicting observation is related to the fact that in PSC biliary tree volume may increase in the intermediate stage of the disease when marked dilatations develop as a response of downstream inflammatory strictures.…”

“…Similarly, Selvaraj et al recently reported that the volume of the whole biliary tree was not correlated with cholestatic indices, LSM, ELF and prognostic scores except for a moderate correlation with the Amsterdam-Oxford score [16]. On the other hand, when the analysis was limited to the intrahepatic biliary tree volume, several correlations with cholestatic indices and prognostic scores were reported [16].…”

“…missing 3D MRCP dataset available for software application or non-isotropic resolution). Given the retrospective nature of our study, these constrains were not possible to overcome but, the recent J o u r n a l P r e -p r o o f results published by Selvaraj et al where they do not exclude patients due to protocol related issues [16] suggests that prospective use of the MRCP+ could improve its applicability.…”

“…Certain metrics were also found to be sensitive to differences across duct width, highlighting quantitative metrics with particular relevance for capturing the features of strictures and dilatation associated with patients with biliary disease [14]. Very recently, two studies conducted in 65 and 76 adult patients with PSC found that that MRCP+ metrics were significantly associated with biochemical prognostic scores and liver stiffness measurement (LSM) and suggested a role for refining risk stratification [15,16]. MRCP+ metrics have also shown utility in characterising disease, stratification and monitoring in paediatric patients [17,18] however, at present, there are no studies which have investigated the correlation between MRCP+ and clinical outcomes in PSC.…”