Ultrasound contrast agents

Abstract

Ultrasound is a real time imaging technique which has traditionally been used for small-animal imaging mainly for its capacity to provide anatomical information with high spatial and temporal resolution. The advent of ultrasound contrast agents and of contrast-specific imaging modes has dramatically increased the importance of ultrasound imaging in both clinical practice and life sciences research. Bolus injections of ultrasound contrast agents allow tracking blood flow in real time not only in large vessels, but also in those of smaller sizes, down to capillaries. Contrast ultrasound allows detailed assessment of tissue perfusion and consequently also detecting not only blood flow abnormalities such as stenoses or occlusions, but also areas of necrosis or vascular growth. This novel imaging technique is also a powerful modality for the detection and characterization of lesions in animal models, for following their evolution over time, and for monitoring the effectiveness of treatments. The recent development of site-targeted ultrasound contrast agents has expanded the role of ultrasound even further into molecular imaging applications. Molecular imaging with ultrasound can be used to visualize the expression of intravascular receptors, and to assess their local concentration over time and/or during therapeutic treatment. Major applications are in the field of inflammation and neoangiogenesis. The combination of anatomic, functional and molecular information/data provided by contrast ultrasound will be a powerful tool in the hands of scientists involved in drug discovery and development and should help reducing the development time of new drugs. This new modality is also ideally suited for translational studies from small animal to human clinical studies. © 2011 Springer-Verlag Berlin Heidelberg.