Gradation of Prolonged Venous Transit on Perfusion Imaging Highlights the Association of Deep Venous Drainage Impairment with Unfavorable Functional Outcome in Successfully Reperfused Anterior Circulation Large-Vessel-Occlusion Stroke

PVT gradation based on Tmax ≥10 seconds timing in distinct venous territories provides prognostic insight into the differential contributions of superficial-versus-deep venous drainage dysfunction, supporting the use of PVT as a meaningful VO imaging biomarker. Deep VO impairment, as reflected by PVT2, is the primary driver of worse functional outcomes despite successful reperfusion in AIS-LVO, indicating its stronger negative prognostic impact compared with superficial VO impairment. These findings can help inform prognosis and postacute management strategies.