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A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
Published on: September 16, 2017
Regional and temporal variations in tissue sodium concentration during the acute stroke phase
Friedrich Wetterling1, Lindsay Gallagher, I Mhairi Macrae
1School of Physics, Trinity College Dublin, University of Dublin, Ireland. wetterlf@tcd.ie
Magnetic Resonance in Medicine
|June 17, 2011
Summary
Noninvasive sodium imaging accurately quantifies tissue sodium concentration (TSC) in ischemic stroke. Delayed TSC increases in the brain
Area of Science:
- Neuroimaging
- Biophysics
- Medical Physics
Background:
- Ischemic stroke diagnosis relies on detecting tissue damage.
- Sodium ((23) Na) magnetic resonance imaging (MRI) shows promise for stroke assessment.
- Previous (23) Na-MRI studies were limited by poor signal-to-noise ratio.
Purpose of the Study:
- To develop and apply an accurate (23) Na-MRI technique for quantifying tissue sodium concentration (TSC) in ischemic stroke.
- To investigate the temporal evolution of TSC in cortical and subcortical ischemic tissue.
- To differentiate between infarcted tissue (core) and potentially salvageable tissue (penumbra) using TSC.
Main Methods:
- Utilized (23) Na-MRI with 1.2 μL voxel size, acquiring images in 10 minutes.
- Studied TSC changes from 0.5 to 8 hours post-middle cerebral artery occlusion in rats.
- Applied a delayed linear model to TSC time course data for kinetic analysis.
Main Results:
- Achieved accurate TSC quantification in high-resolution (23) Na images.
- Found significant correlation between TSC-derived infarct volumes and histology (P = 0.0006).
- Observed immediate TSC increase in subcortical (0.2 ± 0.1 h) versus delayed increase in cortical (1.6 ± 0.5 h) ischemic tissue (P = 0.0002).
Conclusions:
- Accurate (23) Na-MRI enables noninvasive TSC measurement in ischemic stroke.
- The timing of TSC increase differentiates core infarct from penumbra.
- This technique offers potential for improved stroke diagnosis and treatment monitoring.
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