INTRODUCTION: Brain parenchyma contrast staining on CT after recanalization therapy and digital subtraction angiography (DSA) in large vessel occlusion acute ischemic stroke (LVO-AIS) patients has been demonstrated to be a marker for significant brain injury, possibly indicating blood brain barrier breakdown or no-reflow phenomena at the capillary level. Most often stained parenchyma undergoes infarction. We evaluated several DSA parameters in order to determine if findings on DSA at the time of LVO-AIS intervention can predict postintervention parenchymal contrast staining on CT and, thus, serve as early prognostic factors for brain infarction. HYPOTHESIS: Point of cerebral arterial occlusion, TICI score, and degree of pial collateraliation correlate with presence of parenchymal contrast staining on post-intervention CT in LVO-AIS patients. METHODS: Our institution’s CHR approved this analysis of imaging and patient charts. We reviewed 17 years of LVO-AIS intervention at our institution, and 67 patients met inclusion criteria. Angiograms were evaluated for level of occlusion, TICI scores before and after intervention, and level of collateralization before and after intervention. Statistical analysis was performed using Fisher’s exact test and ANOVA. RESULTS: More proximal sites of cerebral arterial occlusion were more likely patients to have post-intervention staining (p=0.08). Preprocedure TICI, postprocedure TICI and improvement in TICI score did not predict contrast staining on post procedure CT (p=0.34, 0.54, and 0.52). Preprocedure collateral score, post procedure collateral score were similarly not predictive (p=0.28 and 0.93). Decreasing collateral score (i.e., increased antegrade flow with decreased need for collateral supply) was predictive of contrast staining (p=0.09). CONCLUSION: Improvement in pial collateral score was more predictive of postprocedure contrast staining than was change in TICI grade, and thus may serve as a complement to TICI in the assessment of revascularization efficacy at the time of stroke intervention.