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Updated: Jan 27, 2026
09:59
A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
Published on: September 16, 2017
14.6K
Mapping a Reliable Stroke Onset Time Course Using Signal Intensity on DWI Scans
Michael M Chen1, Patrick M Chen1, Lovella Hailey1
1Department of Neurosciences, University of San Diego Health, Stroke Center, San Diego, CA.
Summary
Diffusion-weighted imaging (DWI) intensity correlates with time since stroke onset. This finding supports using DWI signal intensity to estimate the last known well (LKW) time for acute stroke patients.
Area of Science:
- Neurology
- Radiology
- Medical Imaging
Background:
- Establishing a last known well (LKW) time surrogate is critical for optimizing acute stroke treatment.
- Diffusion-weighted imaging (DWI) signal intensity increases post-stroke, but a reliable time-intensity correlation is not established.
Purpose of the Study:
- To investigate the correlation between DWI signal intensity and time from stroke onset.
- To assess the potential of DWI intensity as a surrogate for LKW time in acute stroke.
Main Methods:
- Retrospective review of 78 acute stroke patients from the UCSD Stroke Registry (1/2016-6/2017).
- Measurement of relative DWI (rDWI) intensity using IMPAX software, comparing DWI signal to the contralateral healthy side.
- Pearson correlation coefficient used to assess the relationship between DWI intensity, rDWI, and time to MRI.
Main Results:
- A statistically significant positive correlation (r=0.53, P < .001) was observed between DWI intensity and LKW time across all scanner strengths.
- Analysis using 1.5T MRI showed good correlation (r=0.46, P < .001).
- 3T MRI analysis revealed a stronger positive correlation (r=0.66, P < .001).
Conclusions:
- A strong correlation exists between DWI intensity and time from stroke onset to MRI.
- DWI intensity measurements show potential for extrapolating LKW time in acute stroke.
- Further research is needed to enhance generalizability and clinical experience.
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