ABSTRACT
The definition of tissue at risk of infarction is an important goal in the selection of acute stroke patients likely to benefit from thrombolytic therapy and to extend the therapeutic time window. The concept of the ischemic penumbra, defined as an area of severely hypoperfused but potentially restorable tissue around the irreversibly infarcted core, was introduced by Astrup et al. (1). Over two decades ago, they predicted that cerebral imaging could potentially be used to rapidly diagnose this partially ischemic region, that might be amenable to therapy (2).
