Abstract: Objective To observe the differences of display effects of excretory MR cholangiography（MRCG）to the biliary tract after injection of multihance，and to evaluate the morphology and excretory function of the biliary tract. Methods We selected 24 cases who were examined by MR，and we compared and analyzed the display effects of enhanced T1 biliary tract reconstructing and excretory MRCG images including 1hour，2hours and 3hours after injection of multihance for the intrahepatic and extrahepatic bile duct，gallbladder and bile duct wall. Results （1）The intrahepatic biliary duct display effects of excretory MRCG-2 hours was better than those of excretory MRCG-3 hours（P<0.05），and there were no significant differences between excretory MRCG-1 hour and MRCG-2 hours（P>0.05）；（2）the extrahepatic bile duct display effects of excretory MRCG-2 hours and MRCG-3 hours was better than those of excretory MRCG-1 hour（P<0.05）；（3）the gallbladder display effect of excretory MRCG-3 hours was better than those of excretory MRCG-2 hour and MRCG-1 hour（P<0.05），and those of MRCG-2 hours was better than those of MRCG-1 hour（P<0.05）；（4）the biliary tract anatomic structure display effects of excretory MRCG-1 hour，MRCG-2 hours and MRCG-3 hours was all better than those of enhanced T1 biliary tract reconstructing images（P<0.05）；（5）the biliary tract wall display effect of enhanced T1 biliary tract reconstructing images was much better than 〖JP2〗those of excretory MRCG-1 hour，MRCG-2 hours and MRCG-3 hours（P<0.05），and the enhanced T1 biliary tract reconstructing images can display the biliary tract thickness、smoothness or not，enhancing characteristics，condition in the bile duct and the surrounding soft tissue. Conclusion The excretory MRCG by enhanced scan with multihance has an important research and clinical application value.The ideal biliary tract delay time of bile excretion period is about 2hours after injection of multihance.

Key words: magnetic resonance imaging, multihance, biliary tract obstructive, fluid MR cholangiopancreatography, excretory MR cholangiography