Acute ischemic stroke (AIS) is the most common cerebrovascular disease with high morbidity, mortality and disability. The imaging evaluation of ischemic penumbra has great clinical implication for early diagnosis and reperfusion therapy of AIS. Here, we reviewed the evaluation methods, advangtages and disadvangtages of computed tomography (CT) and magnetic resonance imaging for ischemic penumbra, and discussed the advantages of one-stop multi-modal CT.