SSPC includes degree of Stenosis, Symptoms, Plaque stability and Compensation of the cerebral blood flow. SSPC, a comprehensive evaluation system on carotid artery stenosis, is established and advocated in this trial in order to make assessment on risk of carotid revascularization preoperatively and prediction of cerebral events postoperatively.

Although, cerebral perfusion and collaterals recruitment are crucial and integral to current treatment and stroke prevention paradigms, most consensus recommendations do not include assessments of cerebral hemodynamics in their management algorithms and arbitrarily focus on symptoms and degree of stenosis.

Based on four aspects of SSPC multidimensional assessment and grading, through clinical data, specimen collection, image technology of the multi-disciplinary cross research, we initially to propose a more scientific evaluation system for the perioperative period of carotid revascularization, to reveal the scientific mechanism of brain function changes after carotid revascularization, and to establish a method for the evaluation of brain function after carotid revascularization in accordance with the characteristics of Chinese lesions.

Inclusion Criteria:

1. Patient or patient's legal representative have been informed of the nature of the study, agrees to participate and has signed an Ethical Committee approved consent form
2. Unilateral or bilateral carotid artery stenosis diagnosed by ultrasound or CT angiography.
3. Complete revascularization followed by carotid endarterectomy or carotid artery stenting.

Exclusion Criteria:

1. Patients with carotid stenosis received best medicine therapy.
2. Patients for whom antiplatelet therapy, anticoagulants, medium contrast, or thrombolytic drugs are contraindicated.
3. Patient has bleeding diathesis, coagulopathy, known hypercoagulable condition or refuses blood transfusion
4. female patient with childbearing potential not taking adequate contraceptives or currently breastfeeding.
5. Life expectancy of less than twelve months.
6. Patient is currently participating in another investigational drug or device study that has not completed the entire follow up period.
7. Patient presenting one of the following comorbid conditions: hemodialysis, elevated creatine levels (> 2.5mg/dl), recent MI or ischemic stroke occurrence (both within 30 days).
8. Patient unwilling or unlikely to comply with Follow-Up schedule

Patients diagnosed with carotid artery stenosis and fulfilled the above eligible criteria in tertiary medical centers in China, will be enrolled consecutively.