Tmax profile in computed tomography perfusion-based RAPID software maps influences outcome after mechanical thrombectomy in patients with basilar artery occlusion

Background Computed tomography perfusion (CTP) parameters have been shown to have predictive value for functional outcomes of patients with basilar artery occlusion (BAO). We report the predictive value of CTP-based software (CTP-Rapid Processing of Perfusion and Diffusion (RAPID); iSchemia View) for functional outcomes of patients with BAO after endovascular therapy (EVT). Methods Patients with BAO who underwent EVT were retrospectively analyzed in our center from December 2019 to July 2021. Baseline characteristics and imaging parameters from non-contrast CT, CT angiography (CTA), and CTP-RAPID were collected for analysis. Results Among the 55 patients enrolled in this study, 22 (40.0%) achieved a good functional outcome (modified Rankin Scale score ≤3 at 90 days). In the univariate analysis, posterior circulation Alberta Stroke Program Early CT Score, Basilar Artery on CT Angiography score, posterior circulation CTA score, posterior communicating artery deficiency, perfusion deficit volume in time to maximum (Tmax) >4 s, Tmax >6 s, and mismatch volume were associated with functional outcomes (all p<0.05). In the multivariate analysis, perfusion deficit volume in Tmax >6 s (OR 1.011 (95% CI 1.001 to 1.020)) and posterior circulation CTA score (OR 0.435 (95% CI 0.225 to 0.840)) remained independent outcome predictors (all p<0.05). Conclusions Perfusion deficit volume in Tmax >6 s on CTP-RAPID imaging maps and basilar artery on CTA score have potential as functional outcome predictors in patients with BAO after EVT.