Abstract WP133: Phase MRI Clot Characteristic and Radiologic Thrombectomy Outcomes in Acute Ischemic Stroke

Abstract

Background: Magnetic Resonance (MR) susceptibility weighted imaging (SWI) sequences produce filtered Phase images where blood products demonstrate signal intensities opposite to calcifications. Though susceptibility Vessel Sign (SVS) on pre-interventional MRI has been reported as an indicator of outcome following thrombectomy, the association of Phase MR imaging with thrombectomy outcomes is not previously studied. Methods: In this retrospective cohort study of consecutive acute large vessel occlusion strokes with Phase MR imaging prior to thrombectomy, we evaluated the correlation between clot features on pre-interventional MR imaging with radiographic outcomes following thrombectomy. The clot characteristics included the presence of SVS and its geometrical features on both Phase and GRE sequenced MRIs and thrombus extension. Results: A total of 57 patients were included in this analysis (mean age: 65.04 ± 15.8, 33% Female, mean NIHSS: 13.0 (7.5, 19.5), 33% M1 occlusion), among which 52 (91%) patients had positive SVS on phase-sequence MRI. Successful recanalization was achieved in 91% and successful first pass recanalization was observed in 46%. In univariate analysis, baseline demographics and clinical characteristics including age, sex, and comorbidities were not associated with successful recanalization. Homogeneity of Phase-SVS was significantly associated with the first pass successful recanalization (Odds ratio (OR) 1.81; Confidence interval (CI) [1.14-2.88], p: 0.006). Conclusion: Our study suggests MRI Phase-SVS clot homogeneity as a novel predictor of first pass successful recanalization following mechanical thrombectomy in acute stroke.