title: Diffusion tensor imaging in the corpus callosum in children after moderate to severe traumatic brain injury.
abstract: Diffusion tensor imaging (DTI) is a recent imaging technique that assesses the microstructure of the cerebral white matter (WM) based on anisotropic diffusion (i.e., water molecules move faster in parallel to nerve fibers than perpendicular to them). Fractional anisotropy (FA), which ranges from 0 to 1.0, increases with myelination of WM tracts and is sensitive to diffuse axonal injury (DAI) in adults with traumatic brain injury (TBI). However, previous DTI studies of pediatric TBI were case reports without detailed outcome measures. Using mean FA derived from DTI fiber tractography, we compared DTI findings of the corpus callosum for 16 children who were at least 1 year (mean 3.1 years) post-severe TBI and individually matched, uninjured children. Interexaminer and intraexaminer reliability in measuring FA was satisfactory. FA was significantly lower in the patients for the genu, body, and splenium of the corpus callosum. Higher FA was related to increased cognitive processing speed and faster interference resolution on an inhibition task. In the TBI patients, higher FA was related to better functional outcome as measured by the dichotomized Glasgow Outcome Scale (GOS). FA also increased as a function of the area of specific regions of the corpus callosum such as the genu and splenium, and FA in the splenium was reduced with greater volume of lesions in this region. DTI may be useful in identifying biomarkers related to DAI and outcome of TBI in children.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Elisabeth A
authors.initials: EA
authors.lastname: Wilde
authors.forename: Zili
authors.initials: Z
authors.lastname: Chu
authors.forename: Erin D
authors.initials: ED
authors.lastname: Bigler
authors.forename: Jill V
authors.initials: JV
authors.lastname: Hunter
authors.forename: Michael A
authors.initials: MA
authors.lastname: Fearing
authors.forename: Gerri
authors.initials: G
authors.lastname: Hanten
authors.forename: Mary R
authors.initials: MR
authors.lastname: Newsome
authors.forename: Randall S
authors.initials: RS
authors.lastname: Scheibel
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Li
authors.forename: Harvey S
authors.initials: HS
authors.lastname: Levin
mesh_terms: D000293:Adolescent; D016880:Anisotropy; D001930:Brain Injuries / Q000473:pathology* / Q000503:physiopathology / Q000523:psychology; D016022:Case-Control Studies; D002648:Child; D003071:Cognition / Q000502:physiology; D003337:Corpus Callosum / Q000473:pathology* / Q000503:physiopathology; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D015600:Glasgow Coma Scale; D023261:Glasgow Outcome Scale; D006801:Humans; D008297:Male; D017063:Outcome Assessment, Health Care; D020127:Recovery of Function / Q000502:physiology