Reversibility of diffuse magnetic resonance imaging following endovascular therapy in acute ischemic stroke: a systematic review and meta-analysis.

Background: Diffusion-weighted imaging (DWI) can facilitate early stroke diagnosis. Recently, breakthroughs have been made in early intravascular interventions for acute ischemic stroke (AIS). However, the reversibility of DWI after interventions remains unclear. In this meta-analysis, we investigated the relationship between early endovascular therapy (EVT) and DWI reversal (DWI-R), and clinical outcomes were collected.

Methods: Online databases (PubMed, Embase, Web of Science, Medline, and Cochrane Library) were searched for studies enrolling patients who underwent magnetic resonance imaging (MRI)-DWI sequence examination and EVT within 24 h of stroke onset, and follow-up DWI or fluid-attenuated inversion recovery (FLAIR) within 7 days of EVT. The time characteristics of DWI-R, clinical manifestations, imaging data, and clinical outcomes-up were collected and extracted to systematically evaluate DWI-R. Review Manager was used to evaluate the quality of the included studies, and Stata was used to perform the statistical analysis.

Results: Initially, 515 studies were retrieved, of which 5 studies enrolling 1,226 subjects (n=643, 52.4% male) met the inclusion criteria. The pooled prevalence of DWI-R after EVT was 0.23 [95% confidence interval (CI): 0.17-0.28]. Early DWI-R was often transient. The apparent diffusion coefficient (ADC) was validated as a useful tool for predicting lesion survival. Complete reperfusion and shorter time interval from imaging to final reperfusion were independent predictors of DWI-R. DWI-R after EVT was associated with good functional outcomes in patients with stroke.

Conclusions: High-signal areas on DWI were not static after AIS. EVT can reduce DWI expansion, facilitating DWI-R, which is closely associated with early neurological improvement and 90-day clinical outcomes. However, the enrolled studies had small sample sizes and showed significant heterogeneity in DWI-R rate. Factors related to DWI-R have not been comprehensively evaluated, and large-scale prospective clinical studies are required to provide a reference for treatment decision-making.