Diffusion Tensor Imaging for Diagnosing Root Avulsions in Traumatic Adult Brachial Plexus Injuries: A...

Area of Science:

• Neuroimaging
• Radiology
• Neurology

Background:

• Conventional MRI has limited accuracy for diagnosing traumatic brachial plexus root avulsions.
• This diagnostic challenge often leads to invasive surgery or prolonged observation periods for patients.
• There is a need for improved non-invasive imaging techniques to assess brachial plexus injuries.

Purpose of the Study:

• To develop and evaluate a 3 Tesla (3T) diffusion tensor imaging (DTI) protocol for visualizing the brachial plexus.
• To identify traumatic root avulsions of the brachial plexus using DTI and tractography.
• To assess the diagnostic potential of DTI in differentiating normal from avulsed nerve roots.

Main Methods:

• A DTI protocol using single-shot echo-planar imaging was implemented on a 3T scanner.
• Scans were performed on seven healthy adults and 12 adults with confirmed traumatic brachial plexus root avulsions.
• Deterministic tractography was used to reconstruct brachial plexus pathways, and Fractional Anisotropy (FA) and Mean Diffusivity (MD) values were calculated for nerve roots.

Main Results:

• DTI successfully visualized both normal and avulsed brachial plexus roots.
• Avulsed nerve roots showed significantly lower FA (mean difference 0.1) and higher MD (mean difference 0.32 × 10^-3 mm²/s) compared to healthy roots (p < 0.001 for both).
• Tractography achieved 100% negative-predictive value for identifying at least one root avulsion.

Conclusions:

• 3T DTI combined with tractography is a viable method for visualizing normal and avulsed brachial plexus roots.
• The quantitative DTI metrics (FA and MD) can help differentiate between healthy and injured nerve roots.
• This technique holds potential to improve the diagnostic accuracy for traumatic brachial plexus injuries, potentially reducing the need for exploratory surgery.