compilation image showing 4 different brain scans
These MRI images show an ischemic stroke as it is happening and as it recovers. One hour after the onset of stroke symptoms, a region of brain is starved of blood because of clot in an artery [as seen in the colorized version of perfusion MRI] and injured cells within the region light up on the stroke MRI [as seen in the black and white diffusion weighted MRI]. After the clot is dissolved by clot-busting drugs and blood returns to nourish the deprived brain region [second perfusion MRI] much of the injured brain recovers [second DWI].
Credit: NINDS