Choledocholithiasis: Evaluation with MR cholangiography

OBJECTIVE. We performed this study to evaluate the usefulness of a new T2-weighted MR sequence using a half-Fourier acquisition single-shot turbo spin-echo (HASTE) technique in the diagnosis of bile duct stones. SUBJECTS AND METHODS. We prospectively evaluated 23 patients with suspected bile duct calculi using HASTE MR cholangiography and compared that imaging technique with endoscopic retrograde cholangiography and sonography. The study group consisted of 15 women and eight men who were 42-89 years old. Patients were imaged in the axial, coronal, and sagittal planes with a 1.5-T MR scanner using a body coil. Acquisitions of 13 sec each allowed images to be obtained in a single breath-hold. All images were interpreted by two radiologists in a double-blinded fashion. The presence, number, and size of stones were noted, and common bile duct dilatation was assessed. RESULTS. Fifteen of the 23 patients were proven to have common bile duct stones. Stone size ranged from 3 mm to 35 mm (mean, 11 mm). HASTE MR cholangiography revealed stones in 14 (93%) of 15 patients; sonography revealed stones in nine (60%) of 15 patients. In 12 patients, the common bile duct was dilated, as shown by endoscopic retrograde cholangiography, HASTE MR cholangiography, and sonography. On HASTE MR cholangiograms, we measured the diameter of the bile duct in all patients. The mean diameter was 11 mm, which correlated well (r = .82) with a mean diameter of 13.5 mm as measured on endoscopic retrograde cholangiograms. CONCLUSION. HASTE MR cholangiography can noninvasively and rapidly reveal the presence of stones in the common bile duct and allows readers to assess the degree of biliary dilatation. The sequence should be considered as an alternative to endoscopic retrograde cholangiography in patients with clinical evidence of bile duct calculi and in those for whom endoscopic retrograde cholangiography is impossible.