The investigators continuously collected data from 482 AIS inpatients at the Neurology Department of Hebei General Hospital. Both demographic and clinical data were collected from the study subjects. Different head magnetic resonance imaging sequences were used to assess the subjects' CMBs, white matter lesions, and old lacunar infarcts (LI). Various statistical methods, including the t-test, χ2 test, and logistic regression, were used to analyze the gender heterogeneity of the influencing factors for CMBs in AIS patients.

Inclusion Criteria:

• Aged 18 years and older
• Must meet the diagnostic criteria for AIS as presented in the Chinese Guidelines for Diagnosis and Treatment of Acute Ischemic Stroke 2014
• Must be in good physical condition and have the ability to cooperate with MRI examinations
• Must have underwent SWI

Exclusion Criteria:

• MRI contraindications present, such as cardiac pacemaker, cardiac stents, or metal implants
• Head MRI or carotid artery ultrasound suggests the presence of severe stenosis or occlusion in the intracranial or extracranial segments of the cerebral arteries
• Severe comorbid diseases, such as cardiac, pulmonary, hepatic, and renal insufficiencies

In this study, the data of patients with AIS who were admitted to the Department of Neurology of Hebei Provincial People's Hospital from January 2014 to December 2015 were continuously collected.