In this multicenter study, carotid artery color doppler flow imaging and transcranial color code doppler or transcranial doppler will be used to screen the extra-/intra-cranial vessels in chinese populations with transient ischemic attack and ischemic stroke. The aim of this study is to investigate the extra-/intra-cranial atherosclerosis distribution pattern in chinese populations and analyze the influencing factors of atherosclerosis distribution pattern.~1. Ultrasound examinations procedures: According to the guidelines of vascular ultrasonography published by the Chinese Medical Doctor Association (CMDA) in 2009. The stenosis degrees of carotid artery, vertebral artery, subclavian artery as well as the middle cerebral artery are evaluated followed the criteria we published previously (references 1-4).~2. Radiology examinations procedures: Enrolled patients receive CT or MRI examinations to determine the presence and the location of cerebral infarction. If necessary, patients receive CT angiography (CTA) or MRI angiography (MRA) examinations to confirm the degrees of vessel stenosis.~3. The data collected in this study including:~The general informations of enrolled subjects, which include name, gender, age, resident address, telephone number.Each subject is assigned an unique identification number.~The history of stroke risk factors, which include 1) hypertension; 2) atrial fibrillation; 3) smoking; 4) dyslipidemia; 5) diabetes mellitus; 6) lack of physical activity (the standard of physical activity is ≥ 3 times per week and ≥30 min per time and the duration time ≥ 1 year);7) obvious overweight or obesity (BMI ≥ 26.0 Kg/m2);8) with family history of stroke.~The medicines used within recent 2 weeks, the surgery name (such as stenting, carotid endarterectomy)if any.~The results of vascular ultrasonography, ultrasonic cardiogram, radiology examinations, laboratory tests results (blood glucose, lipoproteins pattern, homocystein, C reactive protein, fibrinogen)~4. Statistic analysis plans The Statistical Package for Social Sciences (SPSS version 22.0) software was used for the statistical analyses.~Numerical values are shown as the mean ± standard deviation (SD). The t test or One-way ANOVA is used to compare the numerical values among different groups.~Chi square test is used to analyze the influencing factors on the intra-/extra-cranial atherosclerosis distribution patterns and the relationship between vessel stenosis degrees and the occurence of ischemic stroke.~Logistic regression is used to analyze the influencing intensity of various risk factors on atherosclerosis and ischemic events.~A P value <0.05 was considered statistically significant.~5. Quality assurance plans:~The medical centers implement the projects are the stroke prevention and treatment base hospitals awarded by National Health and Family Planning Commission, P.R. China. The medical centers have the instruments required in this study.~Neurologists, neurosurgeons and vascular ultrasound physicians have received standard training hosted by National Health and Family Planning Commission stroke prevention engineering committee and obtained excellent records.~All the centers conduct the project followed the uniform implementation plans and each center guarantee the data input in time and accurately.~The project has the unique database and data input in uniform format.~There are specific staffs to check the accuracy and completeness of data.
The purpose of this multicenter study is to investigate the extra-/intra-cranial atherosclerosis distribution pattern in chinese populations with transient ischemic attack and ischemic stroke and analyze the influencing factors of atherosclerosis distribution pattern.