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Updated: Dec 13, 2025
A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
Published on: September 16, 2017
On the Origins of Diffusion MRI Signal Changes in Stroke
Stephen J Blackband1,2,3,4, Jeremy J Flint1,2, Brian Hansen5
1Department of Neuroscience, University of Florida, Gainesville, FL, United States.
Abstract:
Magnetic resonance imaging (MRI) is a leading diagnostic technique especially for neurological studies. However, the physical origin of the hyperintense signal seen in MR images of stroke immediately after ischemic onset in the brain has been a matter of debate since it was first demonstrated in 1990. In this article, we hypothesize and provide evidence that changes in the glial cells, comprising roughly one-half of the brain's cells and therefore a significant share of its volume, accompanying ischemia, are the root cause of the MRI signal change. Indeed, a primary function of the glial cells is osmoregulation in order to maintain homeostasis in the neurons and nerve fibers for accurate and consistent function. This realization also impacts our understanding of signal changes in other tissues following ischemia. We anticipate that this paradigm shift will facilitate new and improved models of MRI signals in tissues, which will, in turn, impact clinical utility.
Insights
Glial cell changes, not previously understood, are the cause of the hyperintense signal in magnetic resonance imaging (MRI) scans of stroke patients. This finding offers a new perspective on brain imaging and stroke diagnosis.
Area of Science:
- Neuroimaging
- Cellular Biology
- Medical Diagnostics
Background:
- Magnetic resonance imaging (MRI) is crucial for neurological studies, particularly for stroke detection.
- The origin of the hyperintense signal in early stroke MR images remains debated since 1990.
Purpose of the Study:
- To investigate the role of glial cells in the MRI signal changes observed immediately after ischemic onset in the brain.
- To propose a new hypothesis explaining the physical origin of the hyperintense MRI signal in stroke.
Main Methods:
- The study provides evidence supporting a hypothesis on the role of glial cells.
- Analysis focuses on glial cell function, specifically osmoregulation, in the context of ischemia.
Main Results:
- Glial cell alterations accompanying ischemia are identified as the primary cause of the hyperintense MRI signal.
- This finding highlights the significant contribution of glial cells, which constitute about half of the brain's cells.
Conclusions:
- Changes in glial cells are the root cause of the MRI signal change in acute stroke.
- This paradigm shift impacts the understanding of signal changes in other ischemic tissues and may improve MRI models and clinical utility.
