Background and Aims: Extracranial carotid artery stenosis is associated with various risk factors. However, its hemodynamic relationship with intracranial arteries remains largely unknown. This study examines the association between internal carotid artery stenosis and shear stress in major intracranial arteries.
Materials and Methods: Patients without stroke and cardiovascular disease who underwent intracranial TOF-MRA and carotid Doppler ultrasonography (CDU) from 2015 to 2021 were included. Extracranial ICA stenosis (no stenosis, <50%, ≥50%) was categorized based on PSV, PSV ratio, and St. Mary’s ratio. The signal intensity gradients (SIG) of major intracranial arteries were derived using VINT software. Hemodynamic indices from CDU and clinical data were analyzed in relation to the SIG of major arteries.
Results: Among 1,138 subjects, the mean ages were 59.85±9.90 for the no-stenosis group (N=445), 64.81±8.49 for the <50% stenosis group (N=562), and 67.54±8.77 for the ≥50% stenosis group (N=131). Mean SIG of BA showed the most significant correlation with ICA stenosis. The lowest SIG group of BA had the lowest PSV and end diastolic velocity among carotid parameters (p<0.05). This group had 2.96 times higher odds of moderate ICA stenosis (CI: 1.60-5.50, p<0.001) and 1.59 times higher odds of hypertension (CI: 1.12-2.25, p=0.009) compared to the highest group, and a lower heart rate (aOR 0.98, CI: 0.97-0.99, p=0.003).
Conclusions: The mean SIG of the BA is negatively correlated with ICA stenosis, indicating a link between ICA stenosis and intracranial hemodynamics. Further studies are needed to confirm this pathophysiological association.