Association between the perfusion/diffusion and diffusion/FLAIR mismatch: data from the AXIS2 trial

J Cereb Blood Flow Metab. 2015 Oct;35(10):1681-6. doi: 10.1038/jcbfm.2015.108. Epub 2015 Jun 3.

Abstract

The perfusion-/diffusion-weighted imaging (PWI/DWI) mismatch and the diffusion/fluid attenuated inversion recovery (DWI/FLAIR) mismatch are magnetic resonance imaging (MRI) markers of evolving brain ischemia. We examined whether the DWI/FLAIR mismatch was independently associated with the PWI/DWI mismatch. Furthermore, we determined whether the presence of the DWI/FLAIR mismatch in patients with the PWI/DWI mismatch would provide additional information regarding last seen normal time (LTM). We used data from the 'AX200 for ischemic stroke' trial (AXIS 2 study NCT00927836). We studied the association between the presence of the DWI/FLAIR and PWI/DWI mismatch, baseline National Institute of Health Stroke Scale (NIHSS), age, ischemic-core volume, gender, intravenous (IV) tissue plasminogen activator (tPA), and perfusion-mismatch volume in univariate analysis. Significant variables (P<0.05) were added into the final multivariate model. We analyzed 197 patients. Seventy-two (37%) had both the PWI/DWI and the DWI/FLAIR mismatch. Patients with the double mismatch pattern had a shorter LTM than patients with the PWI/DWI mismatch alone (Median difference 90 minutes, P<0.01). Multivariate analysis confirmed the independent association between the two mismatch patterns (odds ratio (OR) 2.6, 95% confidence interval (CI) 1.2 to 5.4). Our study implies that the DWI/FLAIR mismatch and PWI/DWI mismatch are strongly associated, independent from LTM. Furthermore, in the presence of the PWI/DWI mismatch, the DWI/FLAIR pattern indicates a shorter LTM. This could have implications in selecting patients for reperfusion therapy.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Cerebrovascular Circulation
  • Diffusion Magnetic Resonance Imaging / methods*
  • Double-Blind Method
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Angiography
  • Male
  • Middle Aged
  • Neuroimaging
  • Stroke / pathology*