Quantitative Evaluation of the Penumbra and Ischemic Core in Acute Cerebral Infarction Using Whole-Brain CT Perfusion

The objectives of the study were to quantitatively assess whole-brain CT Perfusion (CTP) data using an automatic region of interest (ROI) analysis program in order to distinguish between the degree of ischemia in the ischemic core and that in the penumbra and to assess the relationship between expansion of the area of infarction. The subjects were 20 patients with acute cerebral infarction. Whole-brain CTP was performed for all subjects using a 320-row area detector CT scanner. The penumbra* is defined as the region in which the CBV value is 2 mL/100 g or more and the ischemic core* is defined as the region in which the CBV value is less than 2 mL/100 g. The quantitative values of CTP parameters were automatically measured using the automatic ROIs analysis program. The Mann-Whitney U test was applied to differentiate between the ischemic core* and the penumbra*. The reduction in perfusion pressure in the penumbra* was smaller in the group with expansion of the area of infarction than in the group without expansion of the area of infarction. The difference in the median values between the penumbra* and the ischemic core* was larger in the group with expansion of the area of infarction than the group without expansion of the area of infarction. It is considered that the quantitative analysis method using whole-brain CTP may be useful for more accurately distinguishing between the ischemic core and the penumbra and for evaluating the risk of expansion of the ischemic core into the penumbra.