Blog
About

1
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      A pragmatic approach using magnetic resonance imaging to treat ischemic strokes of unknown onset time in a thrombolytic trial.

      Stroke; a Journal of Cerebral Circulation

      methods, Thrombolytic Therapy, therapy, diagnosis, Stroke, Reproducibility of Results, Predictive Value of Tests, Middle Aged, Male, Magnetic Resonance Imaging, Image Processing, Computer-Assisted, Humans, physiology, Functional Laterality, Female, Diffusion Magnetic Resonance Imaging, pathology, Cerebral Infarction, Brain Ischemia, Aged, 80 and over, Aged

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Toward the goal of designing a clinical trial using imaging parameters to treat stroke patients with unknown onset time, we investigated the timing of changes on MRI in patients with well-defined stroke onset. Hypothesis-generating (n=85) and confirmatory (n=111) samples were scored by blinded readers for fluid-attenuated inversion recovery (FLAIR) hyperintensity in diffusion-positive regions. Reader-measured signal intensity ratio (SIR) of the lesion to contralateral tissue was compared with SIR measured by coregistration. Lesion conspicuity increased with time on FLAIR (P=0.006). Qualitative assessment of FLAIR-negative vs FLAIR hyperintensity (k=0.7091; 95% CI, 0.61-0.81) showed good interrater agreement. Subtle hyperintensity was less reliably categorized (k=0.59; 95% CI, 0.47-0.71). Reader-measured SIR <1.15 can identify patients within the treatable time window of 4.5 hours (positive predictive value=0.90). The SIR was greater for right hemisphere lesions (P=0.04) for a given reported time from stroke symptom onset. The SIR on FLAIR provides a quantitative tool to identify early ischemic strokes. In developing SIR thresholds, right hemisphere lesions may confound the accurate estimate of stroke onset time. Image coregistration for thrombolytic trial enrollment is not necessary. A SIR <1.15 on FLAIR yields a practical estimate of stroke onset within 4.5 hours.

          Related collections

          Author and article information

          Journal
          10.1161/STROKEAHA.111.630947
          3464959
          22693129

          Comments

          Comment on this article