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A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
Published on: September 16, 2017
Fluid-attenuated inversion recovery evolution within 12 hours from stroke onset: a reliable tissue clock?
Martin Ebinger1, Ivana Galinovic, Michal Rozanski
1Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Berlin, Germany. martin.ebinger@charite.de
Stroke
|December 26, 2009
Summary
Fluid-attenuated inversion recovery (FLAIR) visibility on MRI is not a reliable marker for estimating stroke onset within 4.5 hours. FLAIR imaging showed low sensitivity and specificity for this crucial time window in stroke patients.
Area of Science:
- Neurology
- Radiology
- Medical Imaging
Background:
- Fluid-attenuated inversion recovery (FLAIR) MRI is being explored as a potential surrogate marker for stroke symptom onset.
- Accurate time of stroke onset is critical for treatment decisions, particularly for thrombolysis within 4.5 hours.
Purpose of the Study:
- To evaluate the hypothesis that FLAIR MRI visibility can accurately determine if a stroke occurred within 4.5 hours of symptom onset.
- To assess the utility of FLAIR imaging in differentiating early ( < 4.5 hours) versus late ( > 4.5 hours) stroke onset.
Main Methods:
- A study included 94 consecutive stroke patients undergoing MRI within 12 hours of symptom onset.
- Two blinded raters assessed FLAIR lesion visibility. Apparent diffusion coefficient (ADC) values, diffusion-weighted imaging (DWI) lesion volume, and FLAIR lesion signal intensity were measured.
Main Results:
- FLAIR-positive patients had a significantly longer median time from symptom onset (189 minutes) compared to FLAIR-negative patients (103 minutes; P=0.011).
- FLAIR negativity showed 46% sensitivity and 79% specificity for identifying patients within the 4.5-hour window.
- FLAIR positivity correlated with DWI lesion volume but not with ADC values or relative signal intensity.
Conclusions:
- FLAIR lesion visibility is not a recommended method for estimating stroke onset within the critical 4.5-hour therapeutic window.
- The study findings do not support the use of FLAIR imaging as a reliable surrogate marker for early stroke detection.
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