Age‐ and sex‐related effects in children with mild traumatic brain injury on diffusion magnetic resonance imaging properties: A comparison of voxelwise and tractography methods

Abstract

Although there are several techniques to analyze diffusion-weighted imaging, any technique must be sufficiently sensitive to detect clinical abnormalities. This is especially critical in disorders like mild traumatic brain injury (mTBI), where pathology is likely to be subtle. mTBI represents a major public health concern, especially for youth under 15 years of age. However, the developmental period from birth to 18 years is also a time of tremendous brain changes. Therefore, it is important to establish the degree of age- and sex-related differences. Participants were children aged 8–15 years with mTBI or mild orthopedic injuries (OI). Imaging was obtained within 10 days of injury. We performed tract-based spatial statistics (TBSS), deterministic tractography using AFQ (Automated Fiber Quantification), and probabilistic tractography using TRACULA (TRActs Constrained by UnderLying Anatomy) to evaluate whether any method provided improved sensitivity at identifying group, developmental, and/or sex-related differences. Although, there were no group differences from any of the three analyses, many of the tracts, but not all, revealed increases of fractional anisotropy (FA) and decreases of axial, radial, and mean diffusivity (AD, RD, and MD, respectively) with age. TBSS analyses resulted in age-related changes across all white matter tracts. AFQ and TRACULA revealed age-related changes within the corpus callosum, cingulum cingulate, corticospinal tract, inferior and superior longitudinal fasciculus, and uncinate fasciculus. The results are in many ways consistent across all three methods. However, results from the tractography methods provided improved sensitivity and better tract-specific results for identifying developmental and sex-related differences within the brain.

Investigating Gray and White Matter Structural Substrates of Sex Differences in the Narrative Abilities of Healthy Adults

“…Therefore, as a follow-up to TBSS, we conducted whole-brain tractography using the default parameters set in the Automated Fiber Quantification Matlab-based software (AFQ; Yeatman et al, 2012). AFQ has been used in both healthy individuals (e.g., Johnson et al, 2014;Deng et al, 2017) and clinical populations, including individuals with developmental disorders (e.g., Libero et al, 2016;Lin et al, 2018), psychiatric conditions (e.g., Sacchet et al, 2014;Deng et al, 2018) and acquired neurological disorders (e.g., Keller et al, 2017;Main et al, 2017;Sarica et al, 2017;Goodrich-Hunsaker et al, 2018;Zhang et al, 2018). The AFQ procedure is described in detail elsewhere (Yeatman et al, 2012).…”

White matter changes associated with cognitive visual dysfunctions in children with cerebral palsy: A diffusion tensor imaging study

“…It is highest (maximum = 1) in major white matter tracts and lower (minimum = 0) in gray matter, cerebrospinal fluid or in damaged white matter, due to disruption of fiber integrity (Werring et al, ). Other variables that characterize white matter integrity include axial diffusivity (AD) which describe diffusivity along the principal eigenvector, and radial diffusivity (RD) represents an average of the eigenvectors perpendicular to the principal direction (Goodrich‐Hunsaker et al, ).…”

Post-Traumatic Stress Symptoms after Pediatric Injury: Relation to Pre-Frontal Limbic Circuitry

“…Microstructural changes are more prominent in patients with greater severity of injury and are not consistently found in studies of mild TBI. 71 Scanning at longer intervals after injury may also highlight degenerative changes that are easier to detect in long-term rather than subacute stages of recovery.…”