RESUMO
BACKGROUND: The high morbidity and mortality of strokes result in enormous costs to our society. In the last decade advanced imaging techniques with high sensitivity in the diagnosis of acute stroke have been developed. Acute thrombolytic treatment beyond 3 h of acute stroke duration requires the demonstration of penumbra or 'tissue at risk'. However, the utility of the mismatch concept to identify the penumbra area is controversial. OBJECTIVE: The aim is to describe the main features of acute stroke on magnetic resonance imaging. METHOD: Information was obtained from a search of the PubMed and Medline databases (keywords: imaging, stroke, diagnosis and infarct) for articles published from 1997. CONCLUSION: To conclude, new imaging biomarkers of relevant mismatch, hemorrhagic transformation and worse outcome should be developed in the future.
