MR imaging of upper abdomen following cholecystectomy. Normal and abnormal findings

To describe the normal MR appearance after cholecystectomy and the findings in patients with postoperative complications using fast pulse sequences in abdominal MR imaging.

In a prospective study of 119 patients, 64 were examined with MR after cholecystectomy. In total, 56 patients with uncomplicated cholecystectomy were examined with MR 1--5 days (mean 1.6 days) after cholecystectomy. Nine patients had an abdominal postoperative complication and 8 of these were examined with MR after the complication commenced 1--12 days after the cholecystectomy.

Oedema in the gallbladder fossa was the only finding in 39 patients (61%), all with uneventful recovery. Small fluid collections in an area consistent with the gallbladder fossa were seen in 9/64 (14%) patients, of which 3 had surgical complications: 1 bleeding and 2 bile duct leakage. Twenty-two (34%) patients had small locally situated fluid collections adjacent to the liver, 14 were uneventful and 8 showed postoperative surgical complications. Seven patients had fluid in the rest of the abdomen of which 5 had surgical complications; 4 due to bile duct leakage and 1 acute pancreatitis. One patient had a postoperative bleeding not seen on MR images.

MR is very sensitive in detecting fluid collections. Early MR findings following cholecystectomy are normally only subtle changes, mainly in the gallbladder fossa. Fluid collections diagnosed elsewhere than in the gallbladder fossa usually indicate a surgical complication and a surgical complication is unlikely if MR fails to show a fluid collection.