FLAIR vascular hyperintensity is associated with cerebral edema in anterior circulation stroke.

OBJECTIVE: T2 Fluid-attenuated Inversion Recovery (FLAIR) vascular hyperintensity (FVH) refers to a slow blood flow through the leptomeningeal collaterals. Whether FVH relates to cerebral edema in acute ischemic stroke (AIS) remains unclear. We aimed to i) explore the association between FVH and cerebral edema in patients with AIS, and ii) whether FVH improves discrimination for cerebral edema when added to NIHSS. METHODS: This retrospective study included consecutive patients with first-ever anterior circulation occlusion admitted to a teaching hospital between June 2020 and October 2024. The exposure was FVH on T2-FLAIR MRI. The primary outcome was cerebral edema, defined as mass effect, tissue distortion, midline shift, or sulcal/ventricular effacement on MRI. Multivariable logistic regression models were used to determine the association between FVH and cerebral edema. We assessed the discriminative performance of FVH using the area under the receiver operating characteristic curve (AU-ROC). RESULTS: Among 855 AIS patients (median age, 67 (IQR 58-74 years; male, 581 [67.9 %]), FVH was detected in 154 (18.0 %) patients, and cerebral edema were observed in 179 (20.9 %) patients. Multivariate regression analysis showed that FVH was significantly associated with cerebral edema (adjusted OR 1.97, 95 %CI 1.46-2.64, p < 0.001). A combination of NIHSS and FVH had a larger AU-ROC than NIHSS alone (0.759 vs 0.729, Delong test p = 0.007). CONCLUSION: FVH is significantly associated with cerebral edema after AIS. Moreover, FVH may help to better predict cerebral edema in this stroke population.