RESUMEN
Objective:To investigate the feasibility and clinical value of 4D flow magnetic resonance imaging (MRI) in evaluating hemodynamics of ischemic stroke patients with intracranial artery stenosis.Methods:Ischemic stroke patients with unilateral middle cerebral artery stenosis admitted from March 2017 to June 2018 in Beijing Tsinghua Changgung Hospital Stroke Center were prospectively enrolled. Time of flight magnetic resonance angiography was used to evaluate vascular stenosis, 4D flow MRI was used to measure net forward flow at the proximal of stenosis, and brain tissue perfusion was acquired simultaneously to validate flow.Results:A total of 33 patients with symptomatic middle cerebral artery stenosis were included [mean age: 56 years; male: 63.6% ( n=21)]. The flow rates among patients with stenosis of <30%, 30%-49%, 50%-69% and ≥70% were (3.56±1.08), (2.96±0.94), (3.72±0.60) and (2.50±1.03) ml/s individually, demonstrating a decreased flow in subjects with severe (≥70%) stenosis ( F=4.34, P=0.008). Further analysis about forward flow and brain tissue perfusion showed that the significant negative correlation between absolute flow rate or relative flow rate and relative time to peak could only be established in subjects with poor collateral (collateral score: 0-2), with r=-0.76 and -0.61 individually, both P<0.05. Conclusion:4D flow MRI could be used as a quantitative flow assessment in subjects with intracranial artery stenosis, and its association with distal brain tissue perfusion depends on collateral status.