MRCP of anatomic variants of biliary tree

Purpose: The aim of this study was to report the frequency of intrahepatic and extrahepatic biliary variants identified with MRCP; results were correlated to literature data. Material and methods: Between October 2006 and August 2008, 316 patients (176 females, 140 males; mean age 55.7, range 12–96 years) underwent MRCP in our Radiology Department using 1.5 T superconductive magnet (Signa HDx,GE), using 8 channels phased array coil. The biliary tree was investigated using conventional SSFSE (thin and radial thick slab), SSFP (thickness 4 mm) and FRFSE 3D (respiratory-triggered and/or breath-hold). 13 patients with excessive dilatation of biliary tree were excluded from evaluation; 15 more patients with incomplete visualization of cystic duct were excluded from cystic duct evaluation. Two radiologists independently reviewed retrospectively MRcholangiograms; they were blinded for their reports. Results: MRCP showed normal biliary duct bifurcation in 166 patients (54.8%), left dorsocaudal branch in 68 patients (22.4%), trifurcation in 28 cases (9.2%), accessory duct in 22 patients (7.3%), aberrant right hepatic duct in 19 patients(6.3%). Normal insertion of cystic duct was demonstrated in 154 patients (53.5%), low cystic duct insertion in 34 patients (11.8%), high cystic duct in 35 patients (12.2%), medial cystic duct insertion in 37 patients (12.8%) and parallel course of the cystic and hepatic ducts in 50 patients (17.4%). Conclusion: Our results showed higher frequency of intrahepatic and extrahepatic biliary variants than literature data.