Imaging Evaluation of Acute Ischemic Stroke

BACKGROUND AND PURPOSE: Imaging is an important aspect of decisions regarding treatment for acute stroke. New imaging techniques using MRI and CT enable estimation of tissue viability. This information may be useful to select patients for acute stroke therapies. SUMMARY OF REPORT: Several clinical trials identified patients with penumbra based on MRI or CT imaging. The results indicate patients with penumbra by imaging improve with reperfusion, but it is not yet clear that thrombolysis is beneficial when patients are selected on this basis. New quantitative techniques for assessing perfusion and diffusion may improve these results. CONCLUSIONS: Identifying reversible patterns on MRI or CT perfusion imaging may ultimately yield better results than the mismatch concept that is currently under active investigation.