Evaluation of Regional White Matter Volume Reduction after Diffuse Axonal Injury using Voxel-based Morphometry

Area of Science:

• Neuroimaging
• Neuroscience
• Radiology

Background:

• Diffuse axonal injury (DAI) is a common consequence of traumatic brain injury.
• Assessing white matter integrity is crucial for understanding cognitive deficits post-DAI.
• Current methods for evaluating white matter changes can be time-consuming and complex.

Purpose of the Study:

• To develop and validate a novel, convenient voxel-based morphometry (VBM) method for quantifying regional white matter volume reduction (rWMVR) after DAI.
• To assess the correlation between rWMVR and cognitive performance in DAI patients.

Main Methods:

• Utilized 3D volumetric MRI scans from 29 patients with moderate cognitive disability post-DAI.
• Employed automated VBM preprocessing using SPM8 and DARTEL for image analysis.
• Calculated Z-scores to determine relative white matter volume reduction and used voxel-based stereotactic extraction estimation (vbSEE) for regional analysis.
• Correlated rWMVR with Wechsler Adult Intelligence Scale III (WAIS-III) scores using Pearson's correlation.

Main Results:

• Significant rWMVR was identified in multiple regions, notably the corpus callosum.
• rWMVR in the splenium of the corpus callosum showed a significant correlation with performance IQ and processing speed index.
• The VBM method demonstrated utility in detecting and quantifying white matter changes.

Conclusions:

• The developed VBM application is a valuable tool for routine clinical evaluation of DAI.
• The method's advantages include its PC-based operation and ability to use standard MR images for volumetric data acquisition.
• This approach facilitates objective assessment of white matter damage and its cognitive sequelae.