MR cholangiography and CT cholangiography of pediatric patients with choledochal cysts

OBJECTIVE. We report our experience using MR cholangiography and CT cholangiography in pediatric patients with choledochal cysts. SUBJECTS AND METHODS. Fourteen patients (two boys, 12 girls; mean age, 7.8 years) with either a preoperative diagnosis of choledochal cyst or a surgical finding of choledochal cyst underwent non-breath-hold MR cholangiography using T2-weighted fat-suppressed fast spin-echo sequences with a 1.5-T magnet, and CT cholangiography with IV infusion of meglumine iodoxamic acid. Radiologic findings were correlated with findings from surgery, operative cholangiography, or percutaneous transhepatic cholangiography. RESULTS. The biliary tree was visualized in all 14 patients with MR cholangiography and in 13 patients (92.9%) with CT cholangiography. In the 11 preoperative cases of choledochal cyst, MR cholangiography correctly showed all cysts and CT cholangiography showed 10 cysts (90.9%). The quality of images on CT cholangiography and MR cholangiography was comparable. The sensitivity of CT cholangiography and MR cholangiography in revealing intrahepatic stones was 83.3% and 66.7%, respectively; the specificity for both techniques was 100%. The rate of detecting the pancreatic duct and the common channel by CT cholangiography and MR cholangiography was 63.6% and 45.5% respectively. After surgery, CT cholangiography was superior to MR cholangiography in revealing the location of biliary-enteric anastomosis and the extent of anastomotic narrowing. CONCLUSION. Because non-breath-hold MR cholangiography is not invasive and does not use ionizing radiation and potentially toxic contrast agents, it is recommended as the imaging technique of choice in children with choledochal cysts. CT cholangiography can be consid ered as an adjunct after surgery and in patients in whom MR cholangiography is unsatisfactory.