Cerebral blood flow measurement, which is applied to patients with cerebrovascular-related diseases, provides useful information about hemodynamic status. There was a method using Doppler ultrasound and phase contrast (PC) MRI, but it was not widely used in clinical practice due to limitations in reproducibility between examiners, complexity of procedure, and time-intensive protocol. We intend to measure cerebral blood flow through the signal-intensity gradient (SIG) technique using Time-of-Flight (TOF) of brain magnetic resonance imaging, which can compensate for the shortcomings of the existing research methods. In addition, by analyzing the correlation with the previous methods, Doppler ultrasound and PC MRI, we will evaluate the effectiveness of our new method.

Inclusion Criteria:

1. Patients 18 years of age or older who have been admitted to the neurology department due to a stroke, and those who have already performed brain magnetic resonance imaging
2. Among the patients (1) who underwent carotid artery Doppler ultrasound
3. Patients who fully understand the research objectives and procedures and wish to participate in clinical research voluntarily
4. If a patient is not fully understood due to a decrease in awareness or consciousness, the consent of the legal representative is required

Exclusion Criteria:

1. Patients whose extracranial artery occlusion or severe stenosis was confirmed in brain magnetic resonance images.
2. Those who judge that the subject is unsuitable for participation in clinical research due to other reasons.

Patients admitted to the neurology department of a tertiary center