Multiphase CTA vs. MRA collateral map for predicting functional outcomes after acute ischemic stroke

Purpose: To compare the prognostic abilities of multiphase CT angiography (mCTA) and multiphase MR angiography (MRA) collateral map in acute anterior circulation ischemic stroke. Methods: This secondary analysis of a prospective observational study included data from participants with acute ischemic stroke due to steno-occlusion of the internal carotid artery and/or middle cerebral artery within 8 h of symptom onset between January 1, 2016, and March 31, 2021. The intermethod agreement of the collateral scores (CSs) from mCTA and the collateral perfusion scores (CPSs) from the MRA collateral map was analyzed. Multiple logistic regression analyses were conducted to determine the prognostic value of mCTA and MRA collateral maps. Results: 169 participants (106 men and 63 women, mean age 69 years ± 13) were included. The agreement between the CSs of mCTA and the CPSs of the MRA collateral map (weighted kappa = 0.44, 95% confidence interval [CI]: 0.37–0.52) of 168 participants was moderate. Younger age (Odds ratio [OR], 0.51; 95% CI, 0.34–0.76; p = 0.001), lower baseline NIHSS scores (OR, 0.89; 95% CI, 0.81–0.99; p = 0.024), CPS 4 (OR, 36.66; 95% CI, 1.79–750.29; p = 0.019) and CPS 5 (OR, 144.10; 95% CI, 1.11–18788.93; p = 0.046) on the MRA collateral map, and successful reperfusion (OR, 9.63; 95% CI, 3.00–30.94; p < 0.001) were independently associated with favorable functional outcomes. Conclusions: Only the MRA collateral map demonstrated clinical prognostic value in acute anterior circulation ischemic stroke patients, demonstrating the superiority of the MRA collateral map over mCTA in collateral assessment.