Reversal of large ischemic injury on hyper-acute diffusion MRI.

Reversal of early ischemic injury on diffusion-weighted MRI (DWI) occurs rarely. In a stroke patient who abruptly developed stupor and left hemiparesis, DWI scanned 78 min after onset demonstrated a large ischemic injury in the right hemisphere with a DWI-ASPECTS (Albert Stroke Program Early Computed Tomography Score) of 5 points, although baseline brain CT was perfectly normal. MR angiography (MRA) showed an occlusion of the right middle cerebral artery trunk, and the patient received intravenous thrombolysis 105 min after onset. A second MRA 30 h later showed complete vessel recanalization, and DWI demonstrated a perfect reversal of the initial large ischemic injury, associated with very small thrombus-fragmented cortical surface infarctions. Outcome at 3 months was a modified Rankin Scale score of 0, and the fluid-attenuated inversion recovery image showed only a small final infarction at the cortical surface. Hyper-acute DWI-defined large ischemic injury may very rarely represent a nearly perfect reversible area, and it may be a therapeutic target.