Relationship between CT angiography-derived collateral status and CT perfusion-derived tissue viability

To explore the relationship between computed tomography (CT) angiography (CTA)-derived collateral status and CT perfusion (CTP)-derived tissue viability. Patients having middle cerebral artery (MCA) M1/M2 segment and/or internal carotid artery (ICA) occlusion and within 12 hours of onset were included. Collateral was graded from 0 to 3 on maximum intensity projection (MIP) images of CTA. The area with relative cerebral blood flow (rCBF) 10 or >12 or >14 seconds was defined as the infarct core, and Tmax >6 seconds as the penumbra. Kruskal–Wallis and Spearman's correlation tests were performed to assess the correlation between collateral grade and infarct size or mismatch ratio. Eighty-three patients were enrolled and 52 of them met the inclusion criteria. Infarct size defined by rCBF 10 or >12 or >14 seconds and mismatch ratios were significantly different among the four groups. The correlation between collateral grades and infarct core using rCBF 12s or >14s. Mismatch ratio for the infarct core defined by rCBF