[Magnetic resonance cholangiopancreatography: comparative study with direct cholangiography]

Magnetic Resonance Cholangiopancreatography (MRCP) is an emergent non invasive diagnostic technique for the study of pancreaticobiliary system. Following the contraindications of traditional Magnetic Resonance, the MRCP is safe for the patient. Images can be obtained without administration of any contrast and not using Rx. The objective of this study is to evaluate the sensitivity and the specificity of MRCP respect direct cholangiography ([endoscopic retrograde cholangiography (ERCP) and percutaneous transhepatic cholangiography (PTC)]. Forty one patients older than 60 years old were included, 19 male and 22 female, 73.5 median age. All of them have clinical diagnosis of obstructive jaundice. The patients were tested with MRCP first, and blinded of this results a direct cholangiography (DC) were done (ERCP 34 and PTC 8), less than 48 hs after MRCP. For the present study, the sensitivity was 100% and specificity was 90% of MRCP in the diagnosis of normal biliary tract. For the dilated biliary tract the sensitivity was 93% and the specificity was 92%. In bile duct obstruction the sensitivity was 88% without false positive. MRCP diagnosed the presence of choledocholithiasis with a sensitivity of 74% and specificity of 95%, lower than reported in other studies. 73% of our patients required some kind of therapeutic intervention. MRCP has high sensibility and specificity in the initial evaluation of patients with clinical obstructive jaundice and could replace the DC when is used for diagnostic purpose.