Methods

Diffusion-weighted imaging (DWI) can identify early infarction and estimate ischemic core lesions.1–7 The ran-dom Brownian motion of water protons determines DWI signal intensity, and the apparent diffusion coefficient (ADC) values are a quantitative measure of diffusion.8 In both animals and human models, ADC values decrease after brain tissue ischemia and are related to metabolism failure and cytotoxic edema.9 Numerous reports have documented that early DWI lesions in patients with ischemic stroke can be reversible; especially after reperfusion therapy.10–15 The incidence, permanence, and clinical significance of DWI reversibility have not been well characterized. Conflicting reports about the incidence and prognostic significance of DWI reversal have been pub-lished.12–16 Some authors think that DWI reversal has clinical significance, whereas others have concluded that DWI reversal is uncommon and unlikely to be clinically meaningful.13,14 The aim of this study was to assess the frequency and the extent of early DWI reversal after endovascular reperfusion therapy and to determine whether early reversal is sustained or transient