Cerebral perfusion imaging predicts final infarct volume after basilar artery thrombectomy

Objectives: Cerebral perfusion imaging may be used to identify the ischemic core in acute ischemic stroke (AIS) patients with a large vessel occlusion of the anterior circulation; however, perfusion parameters that predict the ischemic core in AIS patients with a basilar artery occlusion (BAO) are poorly described. We determined which cerebral perfusion parameters best predict the ischemic core after successful endovascular thrombectomy (EVT) in BAO patients.

Materials and methods: We performed multicenter retrospective study of BAO patients with perfusion imaging before EVT and a DWI after successful EVT. The ischemic core was defined as regions on CTP, which were co-registered to the final DWI infarct. Various time-to-maximum (Tmax) and cerebral blood flow (CBF) thresholds were compared to final infarct volume to determine the best predictor of the final infarct.

Results: 28 patients were included in the analysis for this study. Tmax >8s (r²: 0.56; median absolute error, 16.0 mL) and Tmax >10s (r²: 0.73; median absolute error, 11.3 mL) showed the strongest agreement between the pre-EVT CTP study and the final DWI. CBF <38% (r²: 0.76; median absolute error, 8.2 mL) and CBF <34% (r²: 0.76; median absolute error, 9.1 mL) also correlated well with final infarct volume on DWI.

Conclusions: Pre-EVT CT perfusion imaging is useful to predict the final ischemic infarct volume in BAO patients. Tmax >8s and Tmax >10s were the strongest predictors of the post-EVT final infarct volume.