Choledocolithiasis: Diagnostic accuracy of MR cholangiopancreatography. Three-year experience

The purpose of this study was to evaluate the diagnostic accuracy of MR cho langiopancreatography (MRCP) in the detection of common bile duct stones. A series of 286 consecutive patients were referred for MRCP, that was perfor med with a 1.5 T MR unit, through a non-breath-hold, respiratory-triggered, fat-suppressed, two-dimensional, heavily T-2-weighted fast spin-echo seque nce in the coronal plane. Axial T1 and T-2-weighted sequences were first ob tained. Axial, coronal, and Maximum Intensity Projection images were evalua ted by three independent readers, who were asked to determine whether stone s were present or not inside the biliary tract. The findings of MRCP images were compared with endoscopic retrograde cholangiopancreatography, percuta neous trans-hepatic cholangiography, intra operative cholangiography, surgi cal, or imaging follow-up findings. Two-hundred and seventy-eight out of 28 6 MRCP examinations were judged diagnostic by the three reviewers. Among th e 278 patients included in our study group, biliary tract lithiasis was pro ved in 76 cases (27%). On the basis of reviewers' reading, MRCP had sensiti vity 92-93%, specificity 97-98%,positive predictive value 91-93%, negative predictive value 97-98%, and the diagnostic accuracy ranged between 95% and 96% in the detection of calculi. Interobserver agreement was excellent (K = 0.84, kappa statistic). MRCP showed a high diagnostic accuracy and an exc ellent inter-observer agreement in the detection of common bile duct stones . (C) 1999 Elsevier Science Inc.