An update on clinical applications of hepatospecific contrast media in magnetic resonance imaging of liver parenchyma.

Hepatobiliary-specific contrast agents are now widely used in magnetic resonance imaging (MRI) of liver parenchyma. As extracellular fluid agents, they provide informations regarding lesion vascularity and their use in the hepatobiliary or delayed phase (DPI), and give additional data regarding hepatocyte presence and function. The aim of this article is to review the recent literature about MRI using hepatobiliary-specific contrast agents and to discuss benefits and limits of their clinical applications. Since November 2008, hepatobiliary contrast agents were routinely employed in our Institution for the characterization of equivocal liver lesions detected by other imaging modalities, and for the evaluation of hepatic nodules in liver cirrhosis. The informations provided are particularly relevant for the detection of metastases, for the differentiation between focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA), and for the detection and differentiation between dysplastic nodules (DNs) and hepatocellular carcinoma (HCC) in the cirrhotic liver. The role in the cirrhosis grading and the quantification of liver function is still controversial. Finally, their biliary excretion allows evaluation of anatomy and function of the biliary tree. According to our and reported data, hepatobiliary contrast agents are able to improve liver lesions detection and characterization; their introduction in clinical practice has improved MRI diagnostic efficacy/accuracy, allowing to decrease the number of invasive diagnostic procedures.