CT Angiography Source Images Predict Final Infarct Extent in Patients with Basilar Artery Occlusion

ASPECTS) is a 10-point grading system to quantify ischemic changes in the posterior circulation. We analyzed whether pc-ASPECTS on CT angiography (CTA) source images (CTASI) predicted the final infarct extent and hemorrhagic transformation (HT) rate in patients with basilar artery occlusion. MATERIALS AND METHODS: A pc-ASPECTS score of 10 indicates absence of visible ischemic changes in the posterior circulation, and pc-ASPECTS score of 0 indicates ischemic changes in the midbrain, pons, and bilateral thalami, posterior circulation territories, and cerebellar hemispheres. We retrospec-tively studied patients with basilar artery occlusion on CTA within 24 hours from symptom onset. We applied pc-ASPECTS to noncontrast CT (NCCT), CTASI, and follow-up images by 3-reader-consensus and assessed HT on follow-up images. We calculated Spearman correlation coefficients and per-formed linear regression analysis. Final infarct extent and HT rates were compared across dichoto-mized CTASI pc-ASPECTS groups ( 8 vs 8). RESULTS: Among 43 patients, median (range) onset to CTA time was 5.0 hours (range, 0.7–24 hours). Pc-ASPECTS on CTASI (r 0.75; P .001) but not NCCT (r 0.29; P .063) correlated with pc-ASPECTS on follow-up scans. Linear regression demonstrated a significant positive relationship between pc-ASPECTS on CTASI and follow-up scans (R2 0.58; P 01). Median follow-up pc