Contrast ultrasound techniques provide on-line assessments of regional tissue perfusion. Intraoperative clinical studies of cardiac revascularization and renal transplantation have been performed and are currently under active clinical investigation. The potential to diagnose and manage patients through the use of contrast ultrasound techniques is just beginning to be realized. With continued development of the contrast agents and improved computer-aided software analyses programs, the future of the real-time perfusion imaging looks bright.