Wu C, Schnell S, Vakil P, Honarmand A R, Ansari S A, Carr J, Markl M, Prabhakaran S
From the Department of Biomedical Engineering (C.W., M.M.), McCormick School of Engineering, Northwestern University, Chicago, Illinois
Departments of Radiology (C.W., S.S., P.V., A.R.H., S.A.A., J.C., M.M.).
AJNR Am J Neuroradiol. 2017 Mar;38(3):515-522. doi: 10.3174/ajnr.A5051. Epub 2017 Jan 5.
Intracranial atherosclerosis induces hemodynamic disturbance, which is not well-characterized, particularly in cerebral flow redistribution. We aimed to characterize the impact of regional stenotic lesions on intracranial hemodynamics by using 4D flow MR imaging.
4D flow MR imaging was performed in 22 symptomatic patients (mean age, 68.4 ± 14.2 years) with intracranial stenosis (ICA, = 7; MCA, = 9; basilar artery, = 6) and 10 age-appropriate healthy volunteers (mean age, 60.7 ± 8.1 years). 3D blood flow patterns were visualized by using time-integrated pathlines. Blood flow and peak velocity asymmetry indices were compared between patients and healthy volunteers in 4 prespecified arteries: ICAs, MCAs, and anterior/posterior cerebral arteries.
3D blood flow pathlines demonstrated flow redistribution across cerebral arteries in patients with unilateral intracranial stenosis. For patients with ICA stenosis compared with healthy volunteers, significantly lower flow and peak velocities were identified in the ipsilateral ICA ( = .001 and = .001) and MCA ( < .001 and = .001), but higher flow, in the ipsilateral PCA ( < .001). For patients with MCA stenosis, significantly lower flow and peak velocities were observed in the ipsilateral ICA ( = .009 and = .045) and MCA ( < .001 and = .005), but significantly higher flow was found in the ipsilateral posterior cerebral artery ( = .014) and anterior cerebral artery ( = .006). The asymmetry indices were not significantly different between patients with basilar artery stenosis and the healthy volunteers.
Regional intracranial atherosclerotic lesions not only alter distal arterial flow but also significantly affect ipsilateral collateral arterial hemodynamics.
颅内动脉粥样硬化会引发血流动力学紊乱，但其特征尚未完全明确，尤其是在脑血流再分布方面。我们旨在通过使用四维血流磁共振成像来明确局部狭窄病变对颅内血流动力学的影响。
对22例有症状的颅内狭窄患者（平均年龄68.4±14.2岁）进行了四维血流磁共振成像检查，其中颈内动脉狭窄7例，大脑中动脉狭窄9例，基底动脉狭窄6例；并对10名年龄匹配的健康志愿者（平均年龄60.7±8.1岁）进行了检查。通过时间积分流线图来可视化三维血流模式。比较了患者和健康志愿者在4条预先设定的动脉（颈内动脉、大脑中动脉以及大脑前/后动脉）中的血流和峰值速度不对称指数。
三维血流流线图显示，单侧颅内狭窄患者的脑动脉间存在血流再分布。与健康志愿者相比，颈内动脉狭窄患者同侧颈内动脉（P = 0.001和P = 0.001）和大脑中动脉（P < 0.001和P = 0.001）的血流和峰值速度显著降低，但同侧大脑后动脉的血流较高（P < 0.001）。大脑中动脉狭窄患者同侧颈内动脉（P = 0.009和P = 0.045）和大脑中动脉（P < 0.001和P = 0.005）的血流和峰值速度显著降低，但同侧大脑后动脉（P = 0.014）和大脑前动脉（P = 0.006）的血流显著升高。基底动脉狭窄患者与健康志愿者之间的不对称指数无显著差异。
局部颅内动脉粥样硬化病变不仅会改变远端动脉血流，还会显著影响同侧侧支动脉的血流动力学。
