Conventional Doppler provides information on blood flow including both flow and direction and flow velocity. Information on the slowly flowing blood at the capillary level, however, has not previously been available on state of the art Doppler. Contrast enhanced ultrasound provides, for the first time, information on tissue perfusion such that CEUS may now play a role in liver mass characterization and the evaluation of masses in other solid viscera similar to the role of contrast enhanced CT and MR scan. Renal applications include similar mass characterization and evaluation of renal perfusion and the renal vasculature. Surveillance of aortic stent grafts, monitoring RFA, and evaluation of both prostate and breast masses are further areas of interest. Our experience with ultrasound contrast expands progressively, and essentially adds vascular information to any region when blood flow information is required. The addition of CEUS to clinical practice has significant impact on patient management. In patients with an incidental liver mass on sonography, for example, characterization at the time of tis detection reduces the time to diagnosis and decreases referrals to CT or MR scan. Ultrasound contrast agents are easy to use, have a very low incidence of adverse events, and are unaffected by renal function. As they add no radiation for their use, they are highly appropriate in pediatric and young adult patients. Ultrasound is enhanced by addition of contrast agents.