Choledocholithiasis: comparison of MR cholangiography and endoscopic retrograde cholangiography.

PURPOSE: To prospectively compare magnetic resonance (MR) cholangiography with endoscopic retrograde cholangiography (ERC) in the diagnosis of choledocholithiasis.

MATERIALS AND METHODS: Forty-seven patients with suspected choledocholithiasis underwent non-breath-hold, heavily T2-weighted, respiratory-triggered turbo spin-echo MR cholangiography. They then underwent ERC within 5 hours. The results of the two procedures were compared in 45 patients.

RESULTS: The absence of ductal dilatation was shown in 16 patients at MR cholangiography and at ERC. MR cholangiography showed common duct dilatation in 28 of the 29 patients with dilatation shown at ERC. MR cholangiography helped correctly identify 18 of the 19 patients with choledocholithiasis and 22 of the 26 patients without choledocholithiasis. Sensitivity with MR cholangiography was 95%, specificity was 85%, positive predictive value was 82%, and negative predictive value was 96%. Two of the false-positive findings were due to pneumobilia.

CONCLUSION: Non-breath-hold MR cholangiography is as accurate for the evaluation of choledocholithiasis as ERC.