Stroke is a common clinical disease with high disability and mortality, which seriously threatens human life and health.Carotid atherosclerotic plaque rupture is an important pathogenic basis of ischemic stroke, so judging the stability of plaque has important clinical significance in preventing ischemic stroke.Ultrasound, as a convenient, rapid, noninvasive, radiation-free auxiliary examination technology, is widely used in carotid plaque stability examination.At present, there are many methods to judge the stability of carotid plaque based on ultrasound, including two-dimensional ultrasound, contrast-enhanced ultrasound, ultrasound elastography and so on. However, the results of plaque stability judgment by various technologies deviate greatly, which is not conducive to the development of standardized diagnosis and treatment strategies by clinicians.Studies have shown that because the neovascular epidermal cells in atherosclerotic plaques are imperfect, they are easy to rupture after stress, and the ruptured neovasculature will lead to intraplaque hemorrhage, thus causing plaque shedding, and eventually obstructing the cerebrovascular cause stroke.Contrast-enhanced ultrasound can sensitively detect the distribution and course of blood vessels.The plaque's softness and hardness determine its stability, while the difference of lipids, fibers and calcium in the plaque determines its softness and hardness.Real-time ultrasound elastography can provide tissue mechanical parameters, express the soft and hard of tissue with strain value, and provide important reference information for judging plaque stability.At present, elastography technology is used to reflect the hardness of plaque, so as to further judge its stability.However, the elastography parameters are prone to deviations due to the influence of the selected section and the selected region of interest.It can be seen from the above that there is currently a multi-modality method to evaluate the stability of carotid plaque using ultrasound, but there is a lack of a unified and objective reference standard for plaque stability assessment.The purpose of this study is to explore the comprehensive utilization of these modalities under the premise of optimizing each ultrasound modality to provide a unified and objective criterion for judging the stability of carotid plaque.

Inclusion Criteria:

• At least one examination suggested the presence of carotid plaque
• Suitable for CEUS examination
• Voluntary enrollment in this study and signing of informed consent

Exclusion Criteria:

• Among ischemic brain rates caused by non-carotid plaque shedding
• Follow-up Lost
• Pregnant women

Outpatient and inpatient patients with carotid plaque in our hospital