Diagnostic and Prognostic Impact of pc‐ASPECTS Applied to Perfusion CT in the Basilar Artery International Cooperation Study

ABSTRACT BACKGROUND AND PURPOSE The posterior circulation Acute Stroke Prognosis Early CT Score (pc‐APECTS) applied to CT angiography source images (CTA‐SI) predicts the functional outcome of patients in the Basilar Artery International Cooperation Study (BASICS). We assessed the diagnostic and prognostic impact of pc‐ASPECTS applied to perfusion CT (CTP) in the BASICS registry population. METHODS We applied pc‐ASPECTS to CTA‐SI and cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) parameter maps of BASICS patients with CTA and CTP studies performed. Hypoattenuation on CTA‐SI, relative reduction in CBV or CBF, or relative increase in MTT were rated as abnormal. RESULTS CTA and CTP were available in 27/592 BASICS patients (4.6%). The proportion of patients with any perfusion abnormality was highest for MTT (93%; 95% confidence interval [CI], 76%‐99%), compared with 78% (58%‐91%) for CTA‐SI and CBF, and 46% (27%‐67%) for CBV ( P < .001). All 3 patients with a CBV pc‐ASPECTS < 8 compared to 6/23 patients with a CBV pc‐ASPECTS ≥ 8 had died at 1 month (RR 3.8; 95% CI, 1.9‐7.6). CONCLUSION CTP was performed in a minority of the BASICS registry population. Perfusion disturbances in the posterior circulation were most pronounced on MTT parameter maps. CBV pc‐ASPECTS < 8 may indicate patients with high case fatality.