White Matter Abnormalities and Cognitive Deficit After Mild Traumatic Brain Injury: Comparing DTI, DKI, and NODDI

Area of Science:

• Neuroimaging
• Neurology
• Radiology

Background:

• White matter (WM) disruption is a key factor in cognitive impairment following mild traumatic brain injury (mTBI).
• Traditional diffusion tensor imaging (DTI) has limitations in fully assessing WM damage.
• Diffusion kurtosis imaging (DKI) and neurite orientation dispersion and density imaging (NODDI) offer enhanced capabilities for evaluating WM integrity.

Purpose of the Study:

• To investigate complex white matter (WM) changes in the acute stage after mild traumatic brain injury (mTBI) using DTI, DKI, and NODDI.
• To correlate diffusion metrics with cognitive function in mTBI patients.
• To explore the utility of advanced diffusion imaging techniques in understanding mTBI-related neurodegeneration.

Main Methods:

• Utilized DTI, DKI, and NODDI models to calculate eight diffusion metrics from 32 mTBI patients and 31 healthy controls.
• Employed tract-based spatial statistics for voxel-level group difference identification.
• Assessed correlations between diffusion metrics and cognitive test scores, including subgroup analysis based on loss of consciousness.

Main Results:

• mTBI patients exhibited significant white matter (WM) abnormalities and cognitive deficits.
• A positive correlation was observed between WM changes and cognitive impairment.
• The strongest correlation was found between the volume fraction of intracellular water (Vic) in the splenium of the corpus callosum and Digit Symbol Substitution Test scores (p = 0.000, r = 0.481).

Conclusions:

• White matter (WM) alterations, particularly in the splenium of the corpus callosum, are significantly correlated with cognitive deficits post-mTBI.
• DKI and NODDI provide complementary information to DTI, enhancing the assessment of WM integrity and injury.
• Advanced diffusion imaging techniques like DKI and NODDI are crucial for a comprehensive understanding of acute mTBI effects on brain structure and function.