Diagnostic Accuracy for Hemodynamically ICAS of MR-FFR Comparing With Pressure-wire-based FFR.

This study will perform a head-to-head comparison between MR-FFR and pressure-wire-based FFR in patients with ICAS. Pressure-wire-based FFR will be used as the gold standard for intravascular pressure gradient measurement. The efficacy and safety of non-invasive FFR will be assessed in this study.

Inclusion criteria

• Patients aged 18 years or older.
• Patients with transient ischemic attack (TIA) or nondisabling ischemic stroke caused by a focal ICAS lesion located in intracranial anterior circulation (intracranial internal carotid artery and their major branches).
• 50% to 99% stenosis (calculated by modified WASID method) of responsible arterial occlusion, confirmed by digital subtraction angiography (DSA).
• Informed of the study protocol and objectives.

Exclusion criteria

• Non-atherosclerotic MCA stenosis
• Combined with moderate or severe stenosis of other extracranial and intracranial arteries
• Previous endovascular treatment or surgery for cerebrovascular diseases
• Large cerebral infarction (more than 1/2 MCA perfusion area)
• Combined with other neurological diseases, such as aneurysm, arteriovenous malformation, tumor, hydrocephalus, cerebral trauma, cerebral hemorrhage, multiple sclerosis, epilepsy and intracranial infection.
• Vascular abnormality or stunting, resulting in the impossibility of endovascular intervention
• Liver and kidney dysfunction, or severe allergy to the contrast agent
• Severe coagulation dysfunction
• Pregnancy or in the preparation for pregnancy
• Patients who cannot tolerate or do not allow MR screening, including metal implanting and claustrophobia
• Patients with severe dementia or mental disorders, who cannot cooperate with examination