Reversal of a Large Ischemic Lesion with Low Apparent Diffusion Coefficient Value by Rapid Spontaneous Recanalization

Cytotoxic edema at the site of a lesion following cerebral infarction is shown as a high signal on diffusion-weighted imaging, with a corresponding decreased apparent diffusion coefficient value on magnetic resonance imaging. These imaging findings have been used clinically as imaging markers of the infarction core, implying irreversible ischemic damage. However, reversal of diffusion lesions has been reported in patients with small lesions, relatively higher values of the apparent diffusion coefficient, or rapid endovascular reperfusion. Herein, we report a case of reversal of a large ischemic lesion on diffusion-weighted imaging with corresponding low apparent diffusion coefficient values in an acute middle cerebral artery infarction after immediate spontaneous recanalization. This case suggests that large ischemic lesions revealed by diffusion-weighted imaging may be reversed upon timely reperfusion, and could be considered as therapeutic targets.ope