Lipid emulsions as contrast agents for hepatic sonography: an experimental study in rabbits.

An ultrasound contrast agent capable of increasing hepatic echogenicity would be useful for the detection of hepatic tumors and metastases. Fatty liver is known to produce increased liver echogenicity. Intravenously administered lipid emulsions are phagocytosed by cells of the reticuloendothelial system the liver with transient hepatic lipid accumulation. We examined the effectiveness of three lipid emulsions of differing particle size as potential ultrasound contrast agents using a rabbit liver model. None of the tested emulsions showed any consistent ability to alter liver echogenicity at maximum tolerable doses. Lipid emulsions do not appear to have potential as contrast agents for ultrasound examination of the liver.