Molecular imaging and ultrasound-assisted drug delivery.

Ultrasound imaging is undergoing a major revolution, about to bring this modality well beyond its established role as a low-cost noninvasive real-time imaging modality. Particularly important has been the commercial availability of microbubble-based contrast agents. Several new indications for contrast ultrasound have been developed and have entered clinical practice. The characterization of focal liver lesions and the follow-up of antiangiogenic therapy are two applications that will have a major impact in medical practice. Others, such as prostate cancer diagnosis, are still under investigation and need to be clinically validated. Thanks to its outstanding sensitivity, contrast-enhanced ultrasound is also geared to become the preferred modality for molecular imaging of diseases occurring at the vascular level. Angiogenesis, inflammation, and other endothelial dysfunctions are important targets that can be imaged and investigated with targeted microbubbles. In the field of prostate cancer, targeted agents will facilitate detection and provide additional information on tumor size, and hopefully on aggressiveness as well. Ultrasound can also play a role to deliver drugs or genes locally. This is an exciting area that has become an important field of research. Imaging and drug delivery can be performed simultaneously, thereby achieving the release of a drug, at the site where it is needed, in a most efficient way.