Evidence for axonal beading and loss in traumatic brain injury using ultra-high gradient ex vivo diffusion MRI
Motivation: Understanding the impact of traumatic brain injury (TBI) on axonal microstructure can elucidate neurodegenerative mechanisms and inform novel therapeutics. Goal(s): To investigate post-TBI alterations in axonal microstructure using high-resolution, ultra-high b-value ex vivo diffusion MRI in postmortem human whole-brain specimens. Approach: Four postmortem brains from TBI patients were scanned using 3D diffusion-weighted multi-shot EPI on the Connectome 2.0 MRI scanner. Diffusion data were fitted to the AxCaliber-SMT model to estimate axon diameter, intra-axonal diffusivity, and intra-axonal fraction. Results: Axon diameter and intra-axonal fraction were reduced in focal white matter near cortical contusions, aligning with histopathologically observed features such as axonal beading and loss. Impact: This study leverages the high-performance gradients of the Connectome 2.0 scanner and a state-of-the-art RF coil for ex vivo imaging to create a platform for histopathologic-imaging correlation and elucidate the mechanisms of post-traumatic neurodegeneration.
Authors
- Brian L. Edlow (ORCID: https://orcid.org/0000-0001-7235-8456)
- Bruce Fischl (ORCID: https://orcid.org/0000-0002-2413-1115)
- Amber Nolan (ORCID: https://orcid.org/0000-0002-0139-0974)
- C. Dirk Keene (ORCID: https://orcid.org/0000-0002-5291-1469)
- Hong‐Hsi Lee (ORCID: https://orcid.org/0000-0002-3663-6559)
- Kwok‐Shing Chan (ORCID: https://orcid.org/0000-0001-8427-169X)
- Dongsuk Sung (ORCID: https://orcid.org/0000-0001-6287-2144)
- Boris Keil (ORCID: https://orcid.org/0000-0003-0805-8330)
- Gabriel Ramos‐Llordén (ORCID: https://orcid.org/0000-0003-4020-705X)
- Alina Scholz (ORCID: https://orcid.org/0000-0002-3324-6889)
- Susie Y. Huang (ORCID: https://orcid.org/0000-0003-2950-7254)
- André van der Kouwe (ORCID: https://orcid.org/0000-0002-2754-6594)
- Kristen Dams-O’Connor (ORCID: https://orcid.org/0000-0002-2506-0216)
- Christine Mac Donald
Publication Details
- Journal
- Proceedings on CD-ROM - International Society for Magnetic Resonance in Medicine. Scientific Meeting and Exhibition/Proceedings of the International Society for Magnetic Resonance in Medicine, Scientific Meeting and Exhibition
- Published
- 2025-09-16
- DOI
- https://doi.org/10.58530/2025/2077
- Primary Topic
- Advanced Neuroimaging Techniques and Applications
- Type
- article
- Field-Weighted Citation Impact
- 0.00