Background: Distal hyperintense vessels (DHV) on fluid-attenuated inversion recovery imaging (FLAIR) is a noninvasive and useful imaging marker that reflects leptomeningeal collateral flow. We investigated relationship between DHV and collateral grade on cerebral angiography, and clinical outcome after endovascular therapy (EVT) in patients with AIS.
Methods: We retrospectively analyzed the patients with AIS in two comprehensive stroke centers from October 2013 to February 2016. We selected the patients who underwent FLAIR sequence before EVT. DHV score (range 0-6) was evaluated based on the presence of DHV in each ASPECTS territory (M1-M6). Collateral grades on cerebral angiography were assessed with the American Society of Interventional and Therapeutic Neuroradiology Collateral Grading System (grade 0-4). Favorable clinical outcomes was defined as modified Rankin Scale [mRS] of 0-2 at 90 days.
Results: A total of 60 patients (aged 71.2 ± 10.5 years; initial NIHSS score, 15 ± 8; median DWI-ASPECTS, 7) were included. DHV was detected in 42 patients (70%); median DHV score was 2 (IQR, 1-4). Higher DHV score was significantly related to better collateral flow grade (p <0.001), and favorable outcome (p <0.001). In multivariate analysis, DHV score predicted favorable outcome (OR 2.83 per 1 point; 95% CI 1.71-5.48; p <0.001), independent of stroke severity or successful reperfusion.
Conclusions: DHV score on FLAIR is a marker of collateral flow status and can predict better clinical outcome in patients with AIS after EVT.