How Does the Function of “Small” Vessels Change in Small Vessel Disease?: Insights from Multimodal Cerebral Hemodynamics Imaging at High-fields

Motivation: Given the limitations in resolution and sensitivity, in vivo studies of microvascular function in small vessel disease(SVD) have been notably scarce. Goal(s): Advanced cerebral-hemodynamic techniques have made it possible to unveil functional alterations in SVD explored in this study. Approach: Utilizing a comprehensive microvascular-functional measurement, including 7T-high-resolution phase-contrast and 3T-ASL modeling, we examined the hemodynamics change and its associations with severity of SVD reflected by multidomain cognitive impairments. Results: Flow velocity in lenticulostriate arteries emerged as the most sensitive indicator, while ASL-derived arterial-transit-time(ATT) and cerebral-blood-flow(CBF), reflecting capillary functions, exhibited reduced sensitivity. Our exploration unveiled insights into microvascular pathology and compensatory mechanisms in SVD. Impact: Utilizing cutting-edge cerebrovascular MRI techniques, multiple microvascular hemodynamic metrics provide novel insights into small vessel disease(SVD) pathology in-vivo, revealing the functional damage and compensatory mechanisms. Also, flow velocity in small arteries is proved a promising imaging marker for SVD progression.