• diffusion-weighted imaging
• disease severity
• gadoxetic acid
• magnetic resonance imaging
• primary sclerosing cholangitis
• relative enhancement

Purpose: To analyze the role of qualitative and quantitative 3T MR Imaging assessment as a non-invasive method for the evaluation of disease severity in patients with primary sclerosing cholangitis (PSC).

Materials and methods: A series of 26 patients with histological diagnosis of PSC undergoing 3T MRI and hepatological evaluation was retrospectively enrolled. All MRI examinations included diffusion-weighted imaging, T2-weighted sequences and T1-weighted images, before and after administration of Gd-EOB-DTPA with the acquisition of both dynamic and hepato-biliary phase (HBP). Qualitative analysis was performed by assessment of liver parenchyma and biliary tract changes, also including biliary excretion of gadoxetic acid on HBP. Quantitative evaluation was conducted on liver parenchyma by measurement of apparent diffusion coefficient (ADC) and relative enhancement (RE) on 3-minute delayed phase and HBP. Results of blood tests (ALT, ALP, GGT, total and direct bilirubin, albumin, and platelets) and transient elastography-derived liver stiffness measurements (TE-LSM) were collected and correlated with qualitative and quantitative MRI findings.

Results: Among qualitative and quantitative findings, fibrosis visual assessment and RE had the best performance in estimating disease severity, showing a statistically significant correlation with both biomarkers of cholestasis and TE-LSM. Statistical analysis also revealed a significant correlation of gadoxetic acid biliary excretion with ALT and direct bilirubin, as well as of ADC with total bilirubin.

Conclusions: Qualitative and quantitative 3T MRI evaluation is a promising non-invasive method for the assessment of disease severity in patients with PSC.