Atherosclerotic plaque is closely related to occurrence of cardiovascular and cerebrovascular events. It is very important to access the atherosclerotic plaque stability in early phase for prevention of cardio-cerebral vascular events and treatment plan. Many studies have demonstrated that intraplaque neovascularization is associated with plaque stability. Intraplaque neovascularization in carotid artery can be detected and assessed by contrast-enhanced ultrasound, which is a hot research topic in plaque stability field over recent years.