BACKGROUND: To determine where magnetic resonance (MR) cholangiography can accurately demonstrate the presence, extent, and type of choledochal cysts. METHODS: Ten patients with sonographically suspected choledochal cysts were evaluated with a non-breath-hold MR cholangiography technique. The presence, extent, and type of choledochal cyst were determined. Visualization of the pancreatobiliary junction was recorded. MR cholangiographic findings were correlated with the gold standard of surgery in six patients, endoscopic retrograde cholangiography in two, and a 99mTc hepatobiliary scintigram in one. Three patients underwent intraoperative cholangiography. RESULTS: All MR cholangiograms were correlated with findings at surgery, endoscopic retrograde cholangiography, or 99mTc hepatobiliary scintigraphy. There were seven Todani type 1 and two Todani type 5 choledochal cysts (Caroli's disease). The extent of involvement was correctly demonstrated on all MR cholangiograms. The pancreatobiliary junction could not be identified in any of the cases. Calculi and sludge were correctly identified on the MR cross-sectional images in three patients but were not seen on MR cholangiograms in two. In one patient with an initially misinterpreted choledochal cyst, MR sectional images showed the typical appearance of a hydatid cyst, which was confirmed at surgery. CONCLUSION: MR cholangiography can be used to confirm the diagnosis of choledochal cysts and define the extent of involvement preoperatively. The pancreatobiliary junction, however, is difficult to visualize. Non-biliary cysts such as a hydatid cyst can mimic a choledochal cyst on the MR cholangiogram and should be correlated with the MR cross-sectional images to avoid misinterpretation.
BACKGROUND: To determine where magnetic resonance (MR) cholangiography can accurately demonstrate the presence, extent, and type of choledochal cysts. METHODS: Ten patients with sonographically suspected choledochal cysts were evaluated with a non-breath-hold MR cholangiography technique. The presence, extent, and type of choledochal cyst were determined. Visualization of the pancreatobiliary junction was recorded. MR cholangiographic findings were correlated with the gold standard of surgery in six patients, endoscopic retrograde cholangiography in two, and a 99mTc hepatobiliary scintigram in one. Three patients underwent intraoperative cholangiography. RESULTS: All MR cholangiograms were correlated with findings at surgery, endoscopic retrograde cholangiography, or 99mTc hepatobiliary scintigraphy. There were seven Todani type 1 and two Todani type 5 choledochal cysts (Caroli's disease). The extent of involvement was correctly demonstrated on all MR cholangiograms. The pancreatobiliary junction could not be identified in any of the cases. Calculi and sludge were correctly identified on the MR cross-sectional images in three patients but were not seen on MR cholangiograms in two. In one patient with an initially misinterpreted choledochal cyst, MR sectional images showed the typical appearance of a hydatid cyst, which was confirmed at surgery. CONCLUSION: MR cholangiography can be used to confirm the diagnosis of choledochal cysts and define the extent of involvement preoperatively. The pancreatobiliary junction, however, is difficult to visualize. Non-biliary cysts such as a hydatid cyst can mimic a choledochal cyst on the MR cholangiogram and should be correlated with the MR cross-sectional images to avoid misinterpretation.