Abstract W MP24: Improving Collateral Circulation Evaluation Accuracy: Multiphase CTA on Acute Stroke

Good collateral circulation (CC) associates favourable outcomes on acute stroke patients, but which is the best technique to evaluate it is controversial. Single-phase CTA (sCTA) is widely used, but lacks of temporal resolution, and may mislabel CC. We aim to evaluate a new, quick (not post processing), time resolved technique to evaluate CC: multiphase CTA (mCTA). METHODS: Consecutive <4.5h stroke patients evaluated for reperfusion therapies with confirmed M1-MCA or TICA occlusion by sCTA were included. Two more cerebral CTA acquisitions with 10 and 20 seconds delay were performed for mCTA. CC evaluation is described in the Table. sCTA and mCTA were compared as predictors of clinical, radiological and functional endpoints. Recanalization (REC) was assessed by TCD at 24h. RESULTS: 78 patients were included. Mean age: 66.3±13.6y, median NIHSS 17.5 (IQR 6.3), 52 (66.7%) M1- and 26 (33.3%) TICA-occlusions. Mean time from onset to CTA: 2:32±1:31h. On sCTA, 61.8% patients presented good CC whereas on mCTA, 54....