ABSTRACT
CT perfusion (CTP) has provide a novel approach for the diagnosis of ischemic cerebrovascular diseases. The evaluation indices include cerebral blood flow, cerebral blood volume, time to peak, and mean transmit time. These semi-quantitative indices used for evaluating cerebral blood perfusion have very important significance for the guidance of choosing the best treatment protocol and efficacy observation. CTP is mainly used in acute ischemic stroke to identify penumbra and infarct, as well as predicting hemorrhagic transformation in combination with other means and choosing thrombolytic candidates. In addition, CTP is also used to assess cerebrovascular reserve capacity in patients with chronic ischemic diseases and diagnose cerebral vasospasm in patients with subarachnoid hemorrhage and their efficacy evaluation.