[Diffusion-weighted imaging hyperintensity is reversible in large middle cerebral artery infarction following...

Diffusion-weighted imaging (DWI) is currently the most sensitive technique to diagnose early ischemic stroke. DWI signal hyperintensity is usually considered to suggest irreversible infarct core, but recent studies demonstrated that DWI hyperintensity signal could be reversible on small embolic lesions. Herein we present a case in a 63-year-old male patient, who was admitted to the emergency department with altered mental status and complaint of weakness in the left arm and leg 6.8 h prior to the admission. Emergency cranial magnetic resonance imaging (MRI) and angiography (MRA) revealed occlusion of his right middle cerebral artery (MCA) and large lesions on DWI. The patient underwent intra-artery thrombectomy after evaluation in spite of the large volume of the DWI lesions up to 91.5 mL at the baseline. His right MCA was recanalized at 8.5 h from symptom onset. One week after the procedure, the patient showed reduced DWI lesion volume to 11.58 mL. In this case we observed the reversibility of a large lesion of the anterior artery circulation presenting with hyperintensity on DWI, suggesting that the clinical implication of DWI hyperintensity should be interpreted with caution, and a large volume of baseline DWI hyperintensity may not be a contraindication to thrombectomy. This conclusion, however, awaits further validation by future large-scale randomized controlled trials.