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Dynamic changes in hippocampal diffusion and kurtosis metrics following experimental mTBI correlate with glial reactivity
Braeckman, Kim Descamps, Benedicte Pieters, Leen Vral, Anne Caeyenberghs, Karen Vanhove, Christian
Braeckman, Kim
Descamps, Benedicte
Pieters, Leen
Vral, Anne
Caeyenberghs, Karen
Vanhove, Christian
Abstract
Diffusion magnetic resonance imaging biomarkers can provide quantifiable information of the brain tissue after a mild traumatic brain injury (mTBI). However, the commonly applied diffusion tensor imaging (DTI) model is not very specific to changes in the underlying cellular structures. To overcome these limitations, other diffusion models have recently emerged to provide a more complete view on the damage profile following TBI. In this study, we investigated longitudinal changes in advanced diffusion metrics following experimental mTBI, utilising three different diffusion models in a rat model of mTBI, including DTI, diffusion kurtosis imaging and a white matter model. Moreover, we investigated the association between the diffusion metrics with histological markers, including glial fibrillary acidic protein (GFAP), neurofilaments and synaptophysin in order to investigate specificity. Our results revealed significant decreases in mean diffusivity in the hippocampus and radial diffusivity and radial extra axonal diffusivity (RadEAD) in the cingulum one week post injury. Furthermore, correlation analysis showed that increased values of fractional anisotropy one day post injury in the hippocampus was highly correlated with GFAP reactivity three months post injury. Additionally, we observed a positive correlation between GFAP on one hand and the kurtosis parameters in the hippocampus on the other hand three months post injury. This result indicated that prolonged glial activation three months post injury is related to higher kurtosis values at later time points. In conclusion, our findings point out to the possible role of kurtosis metrics as well as metrics from the white matter model as prognostic biomarker to monitor prolonged glial reactivity and inflammatory responses after a mTBI not only at early timepoints but also several months after injury.
Keywords
mild traumatic brain injury, diffusion magnetic resonance imaging, DTI, DKI, white matter model
Date
2019
Type
Journal article
Journal
NeuroImage: Clinical
Book
Volume
21
Issue
Page Range
1-12
Article Number
ACU Department
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Relation URI
Source URL
Event URL
Open Access Status
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File Access
Controlled