US of liver transplants: normal and abnormal.

Whole-liver transplantation is an accepted and successful method of treating end-stage liver disease. As a result of the shortage of cadaveric livers, split-liver transplantation and living donor liver transplantation are becoming more commonplace. Ultrasonography (US) is the initial imaging modality of choice for detection and follow-up of early and delayed complications from all types of liver transplantation. Vascular complications include thrombosis and stenosis of the hepatic artery, portal vein, or inferior vena cava, as well as hepatic artery pseudoaneurysms and celiac artery stenosis. Biliary complications include leaks, strictures, stones or sludge, dysfunction of the sphincter of Oddi, and recurrent disease. Neoplastic disease in the transplanted liver may represent recurrent neoplasia or posttransplantation lymphoproliferative disorder. Parenchymal disease may take the form of a focal mass or a diffuse parenchymal abnormality. Perihepatic fluid collections and ascites are common after liver transplantation. Knowledge of the surgical technique of liver transplantation and awareness of the normal US appearance of the transplanted liver permit early detection of complications and prevent misdiagnosis.