The incidence of liver tumors is increasing. Up to 1/3 of the general population has diagnosed one or multiple benign lesions. The overall aim of this thesis was to address various aspects of diagnostic contrast-enhanced ultrasound (CEUS) and its capabilities in relation to benign and malignant liver tumors, to other radiological methods, its cost-effectivity and various other topics related to its use. “Is the lesion in the liver benign or malignant?” and “What kind of benign (malignant) lesion is it?” In imaging algorithms, position of liver CEUS is not precisely yet stated. It is somewhere between the quick, generally available, cheap but unspecific and less sensitive B-mode ultrasound and highly specific, costly and academic MRI. We examined various positions of CEUS diagnostics, mainly in liver adenoma and focal nodular hyperplasia, the two most important solid benign liver lesions. Relation of CEUS and point shear wave elastography in these tumors, was also explored. We did not found a strong relation. Further we did the first ever comparison of CEUS to CT in liver pancreas adenocarcinoma metastasis. CEUS improves cost-effectiveness in focal liver lesions, our analysis added the therapeutic phase to this model, as well.