Contrast-enhanced ultrasound (CEUS) depicts renal perfusion abnormalities and can assess vascularity of renal lesions. This article reviews the role of CEUS in the evaluation of renal masses, with a focus on differential diagnosis between cysts, solid tumors, and pseudolesions; characterization of complex cysts; and evaluation of lesions with equivocal enhancement at computed tomography. CEUS has an increasing role for the follow-up of patients undergoing tumor ablation. Emerging perspectives on monitoring angiosuppressive therapies in advanced renal cancer and intraoperative applications are discussed. Microbubbles can be injected without regard for renal function. Serious reactions are rarely reported, compared with iodinated contrast material.
