ABSTRACT
OBJECTIVES: To assess the value of variable flip angle-based T1 liver mapping on gadoxetate disodium-enhanced MRI in patients with primary sclerosing cholangitis (PSC) for evaluation of global and segmental liver function, and determine a possible correlation with disease severity. METHODS: Sixty-one patients (19 female, 42 male; mean age 41 years) with PSC were included in this prospective study. T1 mapping was performed using a 3D-spoiled GRE sequence (flip angles 5°, 15°, 20°, 30°) before, 16 (HP1) and 132 min (HP2) after contrast injection. T1 values were measured and compared (Wilcoxon-Test) by placing ROIs in each liver segment. The mean reduction of T1 relaxation time at HP1 and HP2 was calculated and correlated with liver function tests (LFTs), MELD, Mayo Risk and Amsterdam Scores (Spearman correlation). RESULTS: Significant changes of T1 relaxation times between non-enhanced and gadoxetate disodium-enhanced MRI at HP1 and HP2 could be observed in all liver segments (p < 0.0001). A significant correlation of T1 reduction could be observed with LFTs, MELD and Mayo Risk Score (p < 0.05). CONCLUSIONS: T1 mapping of the liver using a variable flip angle-based sequence is a feasible technique to evaluate liver function on a global level, and may be extrapolated on a segmental level in patients with PSC. KEY POINTS: ⢠T1 mapping enables evaluation of global liver function in PSC. ⢠T1 relaxation time reduction correlates with the MELD and MayoRisk Score. ⢠Extrapolated, T1 mapping may allow for segmental evaluation of liver function.
