Magnetic Resonance-Based Hemodynamic Model in Symptomatic Intracranial Atherosclerotic Disease

Patients diagnosed with symptomatic intracranial atherosclerotic stenosis (sICAS) face an elevated likelihood of experiencing recurrent ischemic cerebrovascular events. The aim of this research was to create simplified computational fluid dynamics (CFD) models using magnetic resonance imaging (MRI) in order to explore the potential correlation between hemodynamic characteristics of sICAS and the risk associated with recurring ischemic cerebrovascular events.

A retrospective analysis was conducted to gather clinical information and imaging data for patients diagnosed with sICAS. The MR images underwent postprocessing and analysis, followed by the development of a CFD model. Magnetic resonance angiography-based computational fluid dynamics models were constructed to quantify translesional, poststenotic to prestenotic pressure ratio and wall shear stress ratio (WSSR) in the responsible blood vessel. The primary objective evaluated was the occurrence of recurrent ischemic cerebrovascular events within the same region during a 1-year timeframe.

We enrolled a total of 230 participants for our investigation. After one year, we observed recurrent ischemic cerebrovascular events in 38 individuals (16.52%). To assess the hemodynamic indexes associated with the responsible lesions, we utilized CFD based on MRI. Interestingly, our findings revealed no significant correlation between any of these indexes and the occurrence of recurrent ischemic cerebrovascular events within a year (P > 0.05). However, subgroup analysis revealed a significant association between stenosis length and pressure ratio (P < 0.001). Simultaneously, both stenosis severity and length were significantly correlated with WSSR (P < 0.001). Furthermore, in comparison to the poor collaterals group, the good collaterals group presented significantly higher WSSprestenotic and WSSstenotic-throat values, along with lower WSSR values.

For patients with transient ischemic attack or ischemic stroke caused by sICAS, the hemodynamic indexes of the simple CFD model based on MRI are not feasible to predict the recurrence of ischemic cerebrovascular events. However, the collaterals exhibited significantly correlation with WSSpre-stenotic, WSSstenotic-throat, and WSSR values.