Csilla Manoczki, MD

Fabritius MP, Tiedt S, Puhr-Westerheide D, Grosu S, Maurus S, Schwarze V, Rübenthaler J, Stueckelschweiger L, Ricke J, Liebig T, et al. Computed Tomography Perfusion Deficit Volumes Predict Functional Outcome in Patients With Basilar Artery Occlusion. Stroke. 2021;52:2016–2023.

Automated CT/MRI perfusion imaging has become the gold standard for therapeutic decision-making of anterior circulation ischemic strokes presenting in the extended time window. However, there is no validated imaging selection criteria available for the less frequent, but more challenging cases of posterior circulation infarcts.

In this study, Fabritius et al. investigated the predictive value of various CT imaging parameters in a cohort of patients who had presented with acute ischemic stroke secondary to basilar artery occlusion and received modern endovascular treatment (with or without prior intravenous thrombolysis). Forty-nine eligible patients were identified retrospectively in the German Stroke Registry between June 2015 and December 2019. The standardized imaging protocol consisted of non-contrast CT, single phase CT-angiogram and whole-brain CT perfusion studies.

The imaging evaluation was carried out via manual segmentation by two independent assessors blinded to all clinical and follow-up imaging data and include the Basilar Artery on Computed Tomography Angiography (BATMAN) score, posterior circulation-CTa score, posterior-circulation collateral score, posterior circulation-ASPECTS scores on non-contrast CT, CT-perfusion maps and CT-angiogram, and perfusion deficit on all CT-perfusion maps.

Successful recanalization (TICI=2b-3) was achieved in 83.3% of the patients and good clinical outcome (mRS=0-2 at 90 days) in 49% of the patients.

In the poor clinical outcome group, there were lower BATMAN scores, larger perfusion deficit volumes and lower posterior circulation-ASPECTS scores on all CT-perfusion maps. In the multivariate analysis adjusted for age and admission NIHSS, the BATMAN score, perfusion deficit volumes and pc-ASPECTS scores on all CTp maps remained independent predictors of good clinical outcome. In addition, posterior cerebral artery occlusion (p=0.046) and the loss of or hypoplastic posterior communicant arteries (p=0.021) were associated with a poor functional outcome. In contrast to anterior circulation stroke, CT-perfusion mismatch profile did not reach statistical significance (p=0.495). In the receiver operating characteristic analyses, cerebral blood flow (CBF) deficit volume showed an exceptional performance (highest AUC of 0.920), with the ideal CBF cut-off volume of 46ml.

Appreciating the limitations of this study — small cohort size, nonrandomized design and the requirement of manual segmentation — its results may provide valuable guidance for future trials investigating the favorable imaging criteria for therapeutic decision-making in posterior circulation strokes.