Baseline prolonged venous transit on CT perfusion predicts the post-treatment Brush Sign after successful reperfusion in acute ischemic stroke patients.

BACKGROUND: Prolonged venous transit (PVT) on computed tomography perfusion (CTP) indicates impaired macroscopic venous outflow. The Brush Sign on susceptibility-weighted imaging (SWI) reflects microvascular venous congestion and the "no-reflow" phenomenon. We investigated whether pre-treatment PVT independently predicts the post-treatment Brush Sign in patients with anterior circulation acute ischemic stroke with large-vessel occlusion (AIS-LVO) following successful mechanical thrombectomy (MT). METHODS: We retrospectively analyzed patients with anterior-circulation acute ischemic stroke due to large-vessel occlusion who achieved successful reperfusion (modified Thrombolysis in Cerebral Infarction [mTICI] 2b-3) and underwent post-treatment magnetic resonance imaging (MRI). Pre-treatment PVT positivity (Tmax ≥10 s in the superior sagittal sinus and/or torcula) was evaluated on baseline CTP. The primary outcome was the presence of the Brush Sign on follow-up SWI. A multivariable logistic regression model evaluated the independent association between PVT and the Brush Sign, adjusting for age, admission National Institutes of Health Stroke Scale (NIHSS), intravenous thrombolysis, final infarct volume, mTICI score, and baseline Alberta Stroke Program Early CT Score (ASPECTS). RESULTS: Of 187 included patients, 29 (15.5%) demonstrated the Brush Sign. Pre-treatment PVT + was significantly more prevalent in patients who developed the Brush Sign (48.3% vs. 27.2%, p = 0.02). In the adjusted multivariable model (N = 130), PVT + remained a strong, independent predictor of the Brush Sign (OR 3.82, 95% CI 1.32-11.77, p = 0.02). The association remained robust across sensitivity analyses accounting for MRI timing, complete reperfusion, occlusion segment, and suspected stroke etiology. CONCLUSION: Pre-treatment PVT independently predicts the post-treatment Brush Sign in AIS-LVO patients despite successful macrovascular reperfusion. This finding links macroscopic venous congestion to downstream microvascular failure, highlighting PVT as an easily accessible imaging biomarker for anticipating the no-reflow phenotype.