RESUMEN
Diffusion weighted MRI [DWI] scans are very sensitive and specific for the detection of hyperacute and acute infarctions, having a sensitivity of 88%-100% and a specificity of 86%-100%. However, they have certain limitations such as in severely ill patients, artifacts or sometimes unavailability in an emergency. In the current era of thrombolytic therapy, rapid identification of the presence and extent of ischemia is essential. Hence, exploitation of CT perfusion can be helpful in such cases. To identify proper modality in cases of acute stroke in order to set selective criteria for each modality. Showed that both CT perfusion and MRI diffusions are usually complementary to each others as regards identification of the stroke. We can suggest a simple algorithm to choose the proper modality for each patient