[Choledocholithiasis: semeiotic and diagnostic accuracy of cholangiography with magnetic resonance]

The authors report their experience in the optimization of the diagnostic accuracy of Magnetic Resonance Cholangiography (MRC) to detect choledochal stones; pre- and post-MIP post-processing images were compared. Thirty patients with dilated biliary ducts (mean age: 55.6 years) were examined with MRC; two of them had stones in the intrahepatic biliary ducts. The gold standard and the inclusion criterion was ERCP. MRC was carried out with a 1.5 T superconductive magnet (Signa) with T2-weighted FAST SE sequences (TR/TE; 10000/256, matrix: 256 x 128, slice thickness: 3 mm, TA: 6 min 28 s). Coronal MR images were blindly studied before and after MIP post-processing; Friedman's test was used for statistical analysis (p < .05). ERCP showed 92 cases of choledocholithiasis, with the stones ranging .2 to 3.4 cm; MRC before MIP post-processing had 97.1% diagnostic accuracy, 97.8% sensitivity and 95.8% specificity. These values are significantly different from those obtained after MIP (91.4%, 86.9% and 95.8% respectively). In our experience, pre- and post-MIP post-processing MRC can be considered a reliable and accurate noninvasive technique to detect choledochal stones.