P.16.3 THE PROGNOSTIC ROLE OF MAGNETIC RESONANCE CHOLANGIOGRAPHY IN PSC

Background and aim: Magnetic resonance cholangiography (MRC) has became the diagnostic imaging modality of choice when PSC is suspected. The prognosis of this disease, however, is difficult to be determined, considering the survival variability due to the recurrence of complications and the loss of an effective medical therapy. The aim is to evaluate the prognostic role of MRC in patients with PSC. Material and methods: 35 consecutive patients with ERCP-proved PSC (21 males, 14 females; mean age 38 yrs, range 20–73 yrs) underwent MRC at different intervals during the follow-up. MRC images were acquired before and after Primovist® (hepato-specific contrast) administration. The prognostic value of MRC was assessed adapting the original validated Amsterdam classification adopted for ERCP. MRC imaging was scored from 1 (no abnormalities) to 5, based on the severity of biliary strictures and dilatations, both intra- and extrahepatic. The study analyzed the association between MRC score and: liver function tests, the Mayo risk score, the occurrence of clinical events (bacterial cholangitis, pancreatitis, cancer, major strictures requiring an endoscopic/surgical treatment), the contrast enhancement pattern. Results: The median follow-up was 94±76 months. According to the overall imaging score patients were divided in two groups:MRCstage3 (17 patients, 48.6%), MRC stage >3 (18 patients, 51.4%). Age at diagnosis was similar in the two groups (33 vs 29 years, p=n.s.). No significant association was observed between MRC score group and: the occurrence of bacterial cholangitis (17.6% vs 33.3%, p=n.s.), the development of pancreatitis/cancer/major strictures (29.4.6% vs 22.2%, p=n.s.), Mayo score at time of diagnosis (-0.53 vs -0.51, p=n.s.) and LFTs, except for ALT levels at 10 years from diagnosis (0.95 vs 2.56 xULN, p<0.05). After contrast administration, a disomogeneous pattern enhancement, indicating functional exclusion of a portion of the liver parenchyma, was more frequent in the group of patients with MRC score >3 (35.3% vs 72.2%, p<0.05) Conclusions: MRC offers a good performance for prognostic purposes in PSC; in particular, a more severe MRC imaging, in term of biliary strictures and dilatations, indicates the concomitant functional exclusion of liver parenchymal areas. Therefore, the validation of this score is warranted in a larger cohort of PSC patients.