Future applications of contrast ultrasound

Contrast agents are currently used during echocardiography for enhancement of structure and function, as well as for perfusion imaging. The next frontiers in contrast ultrasonography are targeted imaging, and using microbubbles for therapeutic purposes. Targeted imaging is the detection of specific components of cardiovascular disease in vivo, with microbubbles which may non-specifically attach to diseased endothelial cells, or with microbubbles which have been specifically designed to detect a pathologic process. Therapeutic applications of contrast ultrasonography include the use of microbubbles to enhance delivery of agents (like drugs, genes, growth factors, etc.) to the endothelium or perivascular cells. This review will discuss differences in contrast agents used for current applications versus targeted imaging, technical considerations required to achieve site-specific imaging, and potential applications of this technology. The potential for contrast ultrasonography to enhance drug and gene delivery to tissue will also be discussed.