Principles of cerebral ultrasound contrast imaging

Ultrasound contrast is gaining acceptance worldwide as an adjunct to conventional ultrasound imaging. It has clinical applications as diverse as liver disease detection and characterization, myocardial perfusion and wall motion studies, and imaging of cerebral vascularity and perfusion. This paper will focus on imaging techniques used for transcranial ultrasound contrast imaging. The interaction of ultrasound with the microbubbles in the contrast agent is complex and nonlinear. This has led to the development of a variety of imaging modes to improve contrast detection compared with non-contrast optimized modes. This article presents several of these imaging methods in such a way as to help users of ultrasound contrast in the clinic and in research to understand this rapidly developing field.