Liver MRI with T1 and T2 parametric mapping to characterize patients with primary sclerosing cholangitis

The diagnosis of primary sclerosing cholangitis remains difficult, particularly in the absence of typical bile duct strictures. This study aims to assess the diagnostic performance of MRI T1 and T2 mapping with regard to differentiating PSC patients from matched controls.

In this IRB-approved study, we retrospectively included all patients with primary sclerosing cholangitis who underwent multiparametric MRI with T1 and T2 mapping (1.5T and/or 3T) between 09/2018-05/2020 at our institution. Sex-, age-, and field strength-matched patients were selected, without focal or diffuse liver disease and without significant liver steatosis, based on a proton density fat fraction <10%. T1 and T2 relaxation times were compared between patients and controls using a paired Wilcoxon test. Receiver operating characteristic (ROC) curve analysis was performed for the T1 and T2 relaxation times at 1.5T and 3T to discriminate between PSC and non-PSC patients. The cut-off corresponding to the highest Youden index was selected as the optimal threshold.

A total of 132 MRI exams were included: 66 from PSC patients (29 at 1.5T and 37 at 3T), and 66 age-, sex-, and field strength-matched controls. The T2 relaxation time was significantly higher in PSC patients at 3T (38 ms [35-40 ms] vs. 35 ms [31-38 ms]) and 1.5T (53 ms [51-57 ms] vs. 50 ms [46-54 ms]). The T1 relaxation time was significantly higher in PSC patients at 3T (830 ms [793-898 ms] vs. 808 ms [745-864 ms]; p=.01), but not at 1.5 T (620 ms [576-658 ms] vs. 583 ms [544-645 ms]; p=.23). The highest diagnostic performance was observed with T2-weighted sequences at 1.5T (AUC = 0.69, p = .013), followed by T1-weighted sequences at 3T (AUC = 0.65, p = .024). T1-weighted imaging at 1.5T showed a trend toward significance (AUC = 0.64, p = .070), while T2-weighted imaging at 3T did not demonstrate significant discriminative ability (AUC = 0.55, p = .433). For parametric T2 mapping at 1.5T, a >47 ms cut-off showed high sensitivity (89.7%) and moderate specificity (48.3%). For parametric T1 mapping at 3T, a >869 ms cut-off showed high specificity (89.2%) but lower sensitivity (40.5%).

MRI T2 relaxation times were significantly increased in PSC patients both at 3T and 1.5T, while T1 relaxation time was significantly increased at 3T, but not at 1.5T. T2-weighted imaging at 1.5T demonstrated the highest diagnostic performance.

· T2 relaxation time is increased in PSC patients both at 1.5T and 3T.. · T1 relaxation time is increased in PSC patients at 3T, but not at 1.5T.. · T2 relaxation time at 1.5T offers the best diagnostic performance.. · T2 mapping represents a promising diagnostic tool for PSC patients, complementing T1 mapping..

· Huber A, Erb S, Ardoino M etal. Liver MRI with T1 and T2 parametric mapping to characterize patients with primary sclerosing cholangitis. Rofo 2026; 10.1055/a-2836-6899.