Perfusion imaging in late-window thrombectomy identifies salvageable tissue.

• A. Salvageable brain tissue
• B. Large established infarct
• C. No perfusion deficit
• D. Hemorrhagic transformation

Answer: (A)

Perfusion imaging in stroke is used to tell which brain tissue is still at risk but not yet dead—the salvageable tissue. It distinguishes the ischemic penumbra (areas with reduced perfusion that are still viable) from the infarct core (tissue already irreversibly damaged). In the late window for thrombectomy, finding a perfusion deficit that maps to tissue with preserved diffusion indicates there is still salvageable brain that can benefit from reperfusion. So the best answer is salvageable brain tissue, because perfusion imaging helps identify tissue that can be saved with timely clot removal.

The other possibilities don’t fit this context: a large established infarct represents tissue that’s already lost and unlikely to be salvaged; no perfusion deficit would mean there’s no area at risk to target; hemorrhagic transformation is a potential complication rather than a measure of salvageable tissue identified by perfusion imaging.