Adventitial vasa vasorum (VV) as well as intraplaque microvessels are known to be associated with atherosclerotic plaque vulnerability. Contrast-enhanced ultrasound has been validated as a technique to measure the density of VV. Previous studies have demonstrated a relationship between identification of VV and relationship to vascular events such as stroke and myocardial infarction. No previous study has reported the utilization of contrast-enhanced ultrasound identification of VV in the carotid bed as a means of identifying patients at high risk for acute coronary events.