Contrast-enhanced intravascular ultrasound: combining morphology with activity-based assessment of plaque vulnerability

Acute coronary syndromes are the result of coronary plaque rupture in the majority of cases. Available diagnostic techniques that focus on the early detection of plaques that are prone to rupture are still limited. Increased neovascularization in the vasa vasorum of the atherosclerotic plaque has been identified recently as a common feature of inflammation and plaque vulnerability. Microbubbles, which have been used for ultrasound imaging, can be used to trace neovascularization. We present recent advances in contrast agents and contrast-enhanced intravascular ultrasound that may be used for the detection of vasa vasorum, including fundamental and harmonic contrast imaging. Identification of vasa vasorum proliferation in atherosclerotic plaques presents important clinical implications; in particular it could provide a means to detect vulnerability in vivo, thereby guiding targeted treatments.