Exploring the link between white matter hyperintensities volume and cerebral blood flow in normal-appearing white matter using dual post label delays of arterial spin labeling

To explore the link between white matter hyperintensities (WMH) volume and cerebral blood flow (CBF) in normal-appearing white matter (NAWM) using dual-post label delays (PLD) arterial spin labeling (ASL) techniques. Imaging and clinical data were analyzed from 83 patients with cerebral small vessel disease (CSVD) collected between November 2022 and July 2023. WMH volume was segmented using ITK-SNAP software. The difference in CBF between the two PLDs, ΔCBF, was calculated as CBF(PLD = 2.5s) - CBF(PLD = 1.6s). CBF values for both PLD times (PLD = 1.6s, PLD = 2.5s) and ΔCBF were quantified for NAWM regions. Pearson correlation analysis revealed significant associations between WMH volume and both CBF (PLD = 2.5s) ( r = 0.298, P < 0.05) and ΔCBF ( r = 0.287, P < 0.05) in NAWM. When WMH volume was stratified into tertiles, significant differences in CBF (PLD = 2.5s) and ΔCBF were observed among the tertile groups ( P < 0.05). Multivariate regression analysis showed that CBF (PLD = 2.5s) and ΔCBF in NAWM were independently associated with WMH volume after adjusting for age, sex, and vascular risk factors ( P < 0.05). The β coefficient for CBF (PLD = 2.5s) was 0.258 (95% CI: 0.063, 0.453), and for ΔCBF, it was 0.327 (95% CI: 0.109, 0.545). Greater WMH volume was weakly associated with higher NAWM CBF at a PLD of 2.5s and higher ΔCBF. These findings may reflect ATT-related hemodynamic differences, but ATT was not directly measured.