CT angiography collateral scoring: Correlation with DWI infarct size in proximal middle cerebral artery occlusion stroke within 12 h onset

PurposeIt had been postulated that intra-cranial collateral flow can maintain penumbra and limit infarct growth in acute stroke patients. CT angiography is a frequently performed non-invasive modality for evaluation of intracranial collaterals. In this study, we sought to assess whether there is correlation between degree of collateral circulation as determined by CTA and admission DWI infarct size.Patients and methodsWe analyzed thirty patients with proximal middle cerebral artery occlusion within 12 h of onset. The grade of CTA intra-cranial collaterals was evaluated using Maas system and modified Tan scale. Admission DWI infarct volumes were calculated. Spearman correlation coefficient was used to assess relationship between CTA collateral score (CS) and DWI infarct size.ResultsDirect inverse correlation was found between CTA CS and infarct volume (r = −0.5, p = 0.001). ROC analysis showed CS as a good discriminator of DWI volume (AUC = 0.8, p = 0.001). Small infarct size was a significant predictor of good CS (p = 0.01).ConclusionsIn patients with major acute MCA occlusion strokes, CTA collateral grading is significantly correlated with admission DWI size. This finding may be relevant for clinical practice and helpful for guiding treatment decision and predicting clinical outcome.