Associations Between Quantitative MRI Metrics and Clinical Risk Scores in Children and Young Adults With Autoimmune Liver Disease.

ABSTRACT

BACKGROUND. The Mayo risk score and SCOPE (Sclerosing Cholangitis Outcomes in Pediatrics) index are clinical risk scores for monitoring the progression of primary sclerosing cholangitis (PSC) and predicting clinically important endpoints. OBJECTIVE. The purpose of this study was to evaluate relationships between quantitative MRI measures of liver disease and clinical risk scores in children and young adults with autoimmune liver disease (AILD). METHODS. This prospective study included 58 patients (35 male and 23 female patients; mean age, 15.1 ± 1.1 [SD] years [range, 6-24 years]) with AILD (16 with PSC, 30 with autoimmune hepatitis, and 12 with autoimmune sclerosing cholangitis) who underwent research liver MRI examinations including MR elastography, T2*-corrected T1 (cT1), and quantitative MRCP measurements. Associations between quantitative MRI metrics and clinical risk scores were evaluated using Spearman rank-order correlation coefficients and multivariable regression analyses. RESULTS. The mean Mayo risk score was -1.1 ± 0.9 (SD) (range, -2.9 to 1.1); the mean SCOPE index was 2.7 ± 2.2 (range, 0-9). Mean liver stiffness was 2.8 ± 1.1 kPa, whole-liver mean cT1 was 874.7 ± 77.7 ms, and whole-liver cT1 interquartile range (IQR) was 150.8 ± 55.6 ms. The Mayo risk score was significantly correlated with liver stiffness (ρ = 0.56; p < .001), whole-liver mean cT1 (ρ = 0.31; p = .02), whole-liver cT1 IQR (ρ = 0.58; p < .001), and multiple quantitative MRCP measures (ρ = 0.36-0.45, p < .001). SCOPE index was significantly correlated with liver stiffness (ρ = 0.68; p < .001), whole-liver cT1 IQR (ρ = 0.51; p < .001), and multiple quantitative MRCP measures (ρ = 0.47-0.49; p < .001). Multivariable linear regression analyses identified liver stiffness, whole-liver cT1 IQR, and left hepatic duct maximum diameter as significant independent predictors of the Mayo risk score (adjusted R2 = 0.45), and liver stiffness, whole-liver cT1 IQR, maximum common bile duct (CBD) diameter, and median CBD diameter as significant independent predictors of the SCOPE index (adjusted R2 = 0.69). On logistic regression analysis, greater than low risk by SCOPE index was best predicted by liver stiffness [odds ratio [OR] = 49.6; 95% CI, 3.1-793.6) and maximum CBD diameter (OR = 2.5; 95% CI, 1.3-4.7). CONCLUSION. Increased liver stiffness, increased cT1 IQR, and larger bile duct diameters are independently associated with higher (worse) Mayo risk score and SCOPE index among children and young adults with AILD and may be surrogate markers of clinically meaningful endpoints. CLINICAL IMPACT. Multiparametric MRI of the liver incorporating quantitative metrics may serve as a noninvasive diagnostic and prognostic tool in pediatric AILD. TRIAL REGISTRATION. ClinicalTrials.gov NCT03175471.