Contrast-Enhanced Ultrasound Imaging of the Vasa Vasorum : From Early Atherosclerosis to the Identification of Unstable Plaques

Proliferation of the adventitial vasa vasorum (VV) is inherently linked with early atherosclerotic plaque development and vulnerability. Recently, direct visualization of arterial VV and intraplaque neovascularization has emerged as a new surrogate marker for the early detection of atherosclerotic disease. This clinical review focuses on contrast-enhanced ultrasound (CEUS) as a noninvasive application for identifying and quantifying carotid and coronary artery VV and intraplaque neovascularization. These novel approaches could potentially impact the clinician's ability to identify individuals with premature cardiovascular disease who are at high risk. Once clinically validated, the uses of CEUS may provide a method to noninvasively monitor therapeutic interventions. In the future, the therapeutic use of CEUS may include ultrasound-directed, site-specific therapies using microbubbles as vehicles for drug and gene delivery systems. The combined applications for diagnosis and therapy provide unique opportunities for clinicians to image and direct therapy for individuals with vulnerable lesions.