|Title||White Matter Tract Integrity: An Indicator of Axonal Pathology after Mild Traumatic Brain Injury.|
|Publication Type||Journal Article|
|Year of Publication||2018|
|Authors||Chung, S, Fieremans, E, Wang, X, Kucukboyaci, NE, Morton, CJ, Babb, J, Amorapanth, P, Foo, F-YA, Novikov, DS, Flanagan, SR, Rath, JF, Lui, YW|
|ISSN||1557-9042 (Electronic); 0897-7151 (Linking)|
|Keywords||Diffusion, kurtosis, mild traumatic brain injury, MRI, white matter tract integrity|
We seek to elucidate the underlying pathophysiology of injury sustained after mild traumatic brain injury (mTBI) using multi-shell diffusion magnetic resonance imaging, deriving compartment-specific white matter tract integrity (WMTI) metrics. WMTI allows a more biophysical interpretation of white matter (WM) changes by describing microstructural characteristics in both intra- and extra-axonal environments. Thirty-two patients with mTBI within 30 days of injury and 21 age- and sex-matched controls were imaged on a 3 Tesla magnetic resonance scanner. Multi-shell diffusion acquisition was performed with five b-values (250-2500 sec/mm(2)) along 6-60 diffusion encoding directions. Tract-based spatial statistics (TBSS) was used with family-wise error (FWE) correction for multiple comparisons. TBSS results demonstrated focally lower intra-axonal diffusivity (Daxon) in mTBI patients in the splenium of the corpus callosum (sCC; p < 0.05, FWE-corrected). The area under the curve value for Daxon was 0.76 with a low sensitivity of 46.9% but 100% specificity. These results indicate that Daxon may be a useful imaging biomarker highly specific for mTBI-related WM injury. The observed decrease in Daxon suggests restriction of the diffusion along the axons occurring shortly after injury.
bridging the micro-macro gap with diffusion MRI