Hybrid Diffusion Imaging in Mild Traumatic Brain Injury.

Area of Science:

• Neuroimaging
• Radiology
• Neurology

Background:

• Mild traumatic brain injury (mTBI) is a significant public health concern.
• Conventional imaging is often insensitive to mTBI-related white matter damage.
• There is a need for advanced neuroimaging biomarkers for mTBI detection.

Purpose of the Study:

• To investigate the utility of hybrid diffusion imaging (HYDI) techniques for detecting white matter alterations in mTBI patients.
• To compare the sensitivity of advanced diffusion imaging methods (NODDI, q-space) against conventional diffusion tensor imaging (DTI).
• To explore the correlation between diffusion metrics and neuropsychological outcomes in mTBI.

Main Methods:

• 19 mTBI patients and 23 trauma controls underwent magnetic resonance HYDI within 15 days of injury.
• Neuropsychological tests assessed attention, memory, and executive function.
• Tract-based spatial statistics (TBSS) analyzed voxel-wise diffusion metrics, including NODDI-derived intra-axonal volume fraction (V_ic) and q-space measures.

Main Results:

• NODDI-derived V_ic was significantly lower (5-9%) in mTBI patients compared to controls.
• V_ic and q-space measure P₀ correlated with cognitive performance in mTBI patients.
• The relationship between V_ic/P₀ and cognitive function differed significantly between mTBI and control groups, with inverse correlations observed.

Conclusions:

• NODDI and q-space analyses demonstrate superior sensitivity to white matter changes post-mTBI compared to DTI.
• These advanced diffusion imaging techniques show potential as neuroimaging biomarkers for early mTBI detection.
• Findings highlight the utility of advanced diffusion MRI in characterizing mTBI pathophysiology and its cognitive sequelae.