Contrast-enhanced Ultrasonography: The Third Modality for Differentiation of Liver Mass

ABSTRACT

Contrast-enhanced ultrasonography (CEUS) using microbubble ultrasonography contrast agent can show the vascular structure and unique contrast enhancement patterns of focal liver lesions, including hepatocellular carcinoma (HCC). CEUS shows three phases, similar to a vascular pattern on computer tomography (CT), and typical arterial enhancement and portal or late phase washout in HCC. CEUS can show real-time images without nephrotoxicity or radiation hazard and can be used as guidance for loco-regional treatment and estimation of treatment response of HCC. In addition, some data recently revealed the usefulness of CEUS in the early estimation of response to anti-cancer pharmacological (i.e., sorafenib) therapy in advanced HCC. Although CEUS has limitations in clinical practice and more investigation is needed for its validation, it is recommended as a main diagnostic modality in a few major clinical practice guidelines for HCC. Thus, greater understanding of CEUS is necessary to extend its application in real practice for diagnosis and management of diseases.