We wanted to assess the usefulness of MRCP after intravenous morphine administration in the evaluation of the hepatopancreatic pancreatico-biliary ductal system.

We studied 15 patients who were suspected of having disease of hepatopancreatic ductal system and they did not have any obstructive lesion on ultrasonography and/or CT. MRCP was acquired before and after morphine administration (0.04 mg/kg, intravenously). Three radiologists scored the quality of the images of the anatomic structures in the hepatopancreatic ductal system. We directly compared the quality of the images obtained with using the two methods and the improvement of the artifacts by pulsatile vascular compression.

The MRCP images obtained after intravenous morphine administration were better than those obtained before morphine administration for visualizing the hepatopancreatic ductal system. On direct comparison, the MRCP images obtained after morphine administration were better in 12 cases, equivocal in two cases, and the images before morphine administration were better in only one case. In three patients, MRCP before morphine injection showed signal loss at the duct across the pulsatile hepatic artery. In two of three patients, MRCP after morphine injection showed no signal loss in this ductal area.

MRCP after intravenous morphine administration enables physicians to see the hepatopancreatic ductal system significantly better and the artifacts caused by pulsation of the hepatic artery can be avoided.