[Contrast-enhanced sonography of the liver]

The detection rate of liver lesions using ultrasonography is 53-77%, rendering this method inferior to CT and MRI. Despite well-known limitations, development of stable second-generation contrast agents in conjunction with new techniques of contrast display has led to increased diagnostic accuracy. Characterization of focal liver lesions with ultrasound contrast agents follows known features of iodine- and gadolinium-containing contrast agents, but compared to CT and MRI sensitive visualization of intratumoral vessels takes place in real time. In addition to very high diagnostic accuracy in differentiating benign from malignant lesions, detectability of tumors of nonhepatocellular origin is increased significantly and direct assessment of treatment success with minimally invasive tumor ablative interventions in the liver is possible. The active principle of ultrasound contrast agents, examination technique as well as distinguishing features and appearance of various, frequently observed focal liver lesions are illustrated by cases from our department.