Using kinematic MR cholangiopancreatography to evaluate biliary dilatation

OBJECTIVE. The purpose of this study was to evaluate the usefulness of kinematic MR cholangiopancreatographic (MRCP) images as an aid in predicting the need for intervention in patients with biliary dilatation. SUBJECTS AND METHODS. Fifty patients with suspected pancreaticobiliary disorders were separated into three groups. Group I patients had biliary dilatation with periampullary lesions (n = 16), group II patients had supraampullary obstructive lesions (n = 17), and group III patients had biliary dilatation without obstruction (n = 17). Twenty consecutive single thick-slice MRCP images were obtained in the 15degrees or 30degrees left anterior oblique coronal plane. Two radiologists jointly reviewed the images without knowledge of the final diagnosis. The numbers of images showing relaxation of the sphincteric segment and the configuration of the distal margin of the common bile duct for the three groups were compared. RESULTS. Relaxation of the sphincteric segment was observed on the images of only two patients (12%) in group I but on the images of all patients in groups IT and III, although not on all images. Lack of visualization of sphincteric relaxation on the kinematic MRCP images had a sensitivity of 88% and a specificity of 100% for the diagnosis of periampullary lesions. Most patients whose images did not show sphincteric relaxation required biliary intervention at the sphincter level. CONCLUSION. Nonvisualization of sphincteric relaxation on kinematic MRCP indicates ampullary or periampullary lesions. Kinematic MRCP can be used to determine the necessity of biliary intervention in patients with biliary dilatation.