Benign liver masses: imaging with microbubble contrast agents.

Benign focal liver lesions are frequently encountered in routine ultrasound (US) scanning as well as in staging US examination for the patients with known malignancy. Noninvasive characterization of benign liver masses by imaging features has been a challenge for the radiologist. Some benign liver masses show typical findings on US; however, these findings are not highly specific. Contrast-enhanced ultrasound (CEUS) is useful to make an instant, confident diagnosis of benign liver masses. Contrast-enhanced multiphasic computed tomography (CT) is an excellent imaging technique to detect and characterize focal liver masses. But there are a considerable number of indeterminate focal liver lesions, which require further evaluation. CEUS provides the evaluation of perfusion and hemodynamics of nodular liver lesions as well as real-time morphologic evaluation of lesion vascularity. Most benign liver masses show characteristic features on CEUS, allowing an accurate diagnosis. This review article describes typical enhancement features of common benign liver masses.