This study observed the relationship between cerebral collateral circulation and the prognosis of leukoaraiosis in high-risk population. Cerebral collateral circulation and leukoaraiosis levels will be evaluated and followed up by magnetic resonance examination. The participants' clinical performance caused by leukoaraiosis will be assessed by a series of scales.

1. Case collection information is sent daily to clinical trial supervisors.

2. The clinical trial team meets once a week to monitor the quality of clinical trials.

3. The severity of the leukoaraiosis will be evaluated by a scale. The patients whose score is more than 2 will take additional magnetic resonance examination including magnetic resonance angiography (MRA) and arterial spin labeling (ASL). And their cognitive ability will be evaluated by a series of scales including Mini-Mental State Examination (MMSE) and Montreal cognitive assessment (MoCA) and gait by the short physical performance battery (SPPB).

   The blood sample will be taken for biochemical detection and hair and nail samples for trace element detection.

4. Data were analyzed by regression analysis.

Inclusion Criteria:

• Physical Examinees or out-patients
• The MRI scale score ≥ 2

Exclusion Criteria:

• History of stroke
• History of malignant tumor
• History of connective tissue disease
• Pregnant, trying to become pregnant or within 6 weeks after delivery
• serious infections

Inpatients of physical exmination department or out-patients of neurology department in Zhongshan hospital Fudan University.