Diffusion tensor imaging reveals acute subcortical changes after mild blast-induced traumatic brain injury.
Mild blast-induced traumatic brain injury (mbTBI) poses special diagnostic challenges due to its overlapping symptomatology with other neuropsychiatric conditions and the lack of objective outcome measures. Diffusion tensor imaging (DTI) can potentially provide clinically relevant information toward a differential diagnosis. In this study, we aimed to determine if single and repeated (5 total; administered on consecutive days) mild blast overpressure exposure results in detectable structural changes in the brain, especially in the hippocampus. Fixed rat brains were analyzed by ex vivo DTI at 2 h and 42 days after blast (or sham) exposure(s). An anatomy-based region of interest analysis revealed significant interactions in axial and radial diffusivity in a number of subcortical structures at 2 h only. Differences between single- and multiple-injured rats were largely in the thalamus but not the hippocampus. Our findings demonstrate the value and the limitations of DTI in providing a better understanding of mbTBI pathobiology.
1] Department of Anatomy, Physiology and Genetics, The Uniformed Services University, 4301 Jones Bridge Road, Bethesda, MD 20814 [2] Center for Neuroscience and Regenerative Medicine, The Uniformed Services University, 4301 Jones Bridge Road, Bethesda, MD 20814.
Alaa
A
Kamnaksh
1] Radiology and Imaging Sciences, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Room B1N256 MSC 1074, 10 Center Drive, Bethesda, MD 20892 [2].
Matthew D
MD
Budde
US Department of Veterans Affairs, Veterans Affairs Central Office, 810 Vermont Avenue NW, Washington, DC 20420.
Erzsebet
E
Kovesdi
Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910.
Joseph B
JB
Long
Radiology and Imaging Sciences, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Room B1N256 MSC 1074, 10 Center Drive, Bethesda, MD 20892.
Joseph A
JA
Frank
Department of Anatomy, Physiology and Genetics, The Uniformed Services University, 4301 Jones Bridge Road, Bethesda, MD 20814.
Denes V
DV
Agoston
D000818:Animals; D001921:Brain / Q000473:pathology*; D001930:Brain Injuries / Q000175:diagnosis*; D056324:Diffusion Tensor Imaging; D006624:Hippocampus / Q000473:pathology; D008297:Male; D009929:Organ Size; D051381:Rats; D013997:Time Factors