Identification of infarct core and penumbra in acute stroke using CT perfusion source images.

BACKGROUND AND PURPOSE CT perfusion (CTP) mapping has been reported to be useful in the differentiation of the infarct core and ischemic penumbra. However, the value of the CTP source imaging (CTP-SI) during the arterial and venous phases has not been fully investigated. The purpose of this study was to develop a CTP-SI methodology for acute ischemic stroke and compare its efficacy with cerebral blood flow (CBF) and cerebral blood volume (CBV) in predicting infarct core and penumbra. MATERIALS AND METHODS CT examinations, including non-contrast-enhanced CT, CTP, and CT angiography (CTA), were performed in 42 patients with symptoms of stroke for <9 hours. The Alberta Stroke Program Early CT Score (ASPECTS) was analyzed on the arterial phase CTP-SI and venous phase CTP-SI and then compared with the ASPECTS on CBF and CBV for efficacy assessment. RESULTS The ASPECTS on the arterial phase CTP-SI was closely correlated with the ASPECTS on CBF, the Pearson correlation coefficient was 0.88 (P < .001), and the concordance correlation coefficient was 0.7603 (95% confidence interval [CI], 0.6331-0.8476). The ASPECTS on the venous phase CTP-SI revealed a significant correlation with the ASPECTS on CBV, the Pearson correlation coefficient was 0.92 (P < .001), and the concordance correlation coefficient was 0.8880 (95% CI, 0.8148-0.9334). Significant differences were shown between the arterial phase CTP-SI/ venous phase CTP-SI (P < .001) and CBF/CBV (P < .001). CONCLUSIONS This study provides preliminary evidence that the arterial phase and venous phase CTP-SI mismatch model could possibly be applied to ischemic regions in the acute stage of stroke to determine penumbra and infarct core.