Usefulness of MRCP in the Diagnosis of Common Bile Duct Dilatation caused by Non-stone or Non-tumorous Conditions

ABSTRACT

PURPOSE: To evaluate the usefulness of MRCP in the diagnosis of the variable causes of common bile duct(CBD) dilatation, except stone or tumor MATERIALS AND METHODS: Twenty-six patients(MF=1511, mean age; 62 years) with both MRCP and ERCP were included in this study. Dynamic MRCP(n=12) and contrast-enhanced MRI(n=10) of abdomen were also added. Dilatation of CBD, intrahepatic ducts and pancreatic duct was evaluated, including coexistence of intrahepatic ductal stone, pancreatic pseudocyst, and papillitis or papillary edema. The criteria of CBD dilatation was over than 7 mm(n=21, without cholecystectomy) or 10 mm(n=5, with cholecystectomy) in diameter on T2-weighted coronal image. RESULTS: The mean diameter of CBD was 12.7 mm without cholecystectomy(9-19 mm) and 13.0 mm with cholecystectomy(10-15 mm), respectively(p>0.05). Cholangitis(n=11, 42.3%), chronic pancreatitis(n=8, 30.8%), stenosis of distal CBD(n=6, 23.1%), periampullary diverticulum(n=3, 11.5%), stenosis of ampulla of Vater(n=2, 7.7%), dysfunction of sphincter of Oddi(n=2, 7.7%), acute focal pancreatitis in the pancreatic head(n=2, 7.7%), papillitis(n=1, 3.8%), pseudocyst in the pancreatic head(n=1, 3.8%), and ascaris in CBD(n=1, 3.8%) were noted. Pancreatic duct dilatation(n=10, 38.5%) and duodenal diverticulum(n=3, 11.5%) were also seen on MRCP. On dynamic MRCP(12 patients), distal CBD was visualized in 2 patients(16.7%), which was not shown on routine MRCP. Only 1 patient(10.0%) showed papillitis with slightly enhancing papilla on contrast-enhanced MRI(10 patients). CONCLUSION: MRCP was thought to be helpful in the evaluation of the causes of CBD dilatation, not caused by stone or tumor, especially in the cases of stenosis of distal CBD and chronic pancreatitis, dysfunction of sphincter of Oddi on dynamic MRCP, and cholangitis and pericholangitic abnormality on contrast-enhanced MRI