What is the role of CT and MRI in hepatic transplantation?
CT and MRI play an important role in preoperative evaluation of liver transplant donors, as well as in pre- and postoperative evaluation of recipients of liver transplants.
In potential liver donors, preoperative evaluation can be performed with three-phase dynamic contrast-enhanced CT or MRI (depending on particular institution) to delineate the hepatic arterial, portal venous, hepatic venous, and biliary anatomy (because anatomic variations are common) and to measure hepatic lobar volumes. This imaging evaluation is also performed to identify any incidental lesions in the abdomen of the donors, which may or may not need attention prior to surgery.
In potential liver transplant recipients, preoperative evaluation is helpful to delineate the underlying hepatobiliary and vascular anatomy, to evaluate for preexisting hepatobiliary disease, and to stage underlying hepatic malignancy.
Post-transplant evaluation in liver transplant recipients is primarily focused on vascular or biliary complications. Although ultrasonography (US) is often the initial imaging modality to evaluate these patients, CT and MRI are often used for problem-solving. Commonly encountered vascular complications following liver transplantation include thrombosis or stenosis of arteries or veins and arterial pseudo-aneurysm formation. Commonly encountered biliary complications following liver transplantation include biliary stenosis (most commonly at the anastomosis), bile duct strictures, biliary leak, biloma formation, choledocholithiasis, and bile duct necrosis. Other important complications include abdominal abscess, hematoma, recurrence of preexisting malignancy, recurrence of cirrhosis, transplant rejection, and post-transplant lymphoproliferative disorder (PTLD).
