Clinical Research Directory

Inclusion Criteria: 1. Inclusion criteria of the clusters Hospitals with the qualification of "head and neck ultrasound center" in China. 2. Inclusion criteria for individuals * (1)Age ≥ 35 years old, with no restriction on gender. * (2)Patients with clinically diagnosed head and neck stenosis or occlusion, including mild, moderate or severe stenosis or occlusion of the carotid artery and mild, moderate or severe stenosis or occlusion of the intracranial artery. * (3)Ability to use a smartphone and have a mobile application installed on the handset. * (4)Subjects or their legal representatives agreed to the study and signed the project informed consent form. Exclusion Criteria: 1. Exclusion criteria for the clusters The included centers did not have the capacity to undertake the trial. 2. Exclusion criteria for individuals * (1)Combination of severe systemic diseases such as respiratory failure, renal failure, gastrointestinal bleeding, coagulation dysfunction, malignancy, etc. * (2)Patients with a life expectancy of less than 2 years or who are unable to complete the study for other reasons.