title: Heterogeneity of brain lesions in pediatric traumatic brain injury.
abstract: OBJECTIVE
  Magnetic resonance imaging (MRI) provides a method to identify and quantify abnormalities resulting from traumatic brain injury (TBI). MRI abnormalities in children with TBI have not been fully characterized according to the frequency, location, and quantitative measurement of a range of pathologies critical for studies of neuropsychological outcome. Here, we report MRI findings from a large, multicenter study of childhood TBI, the Social Outcomes of Brain Injury in Kids (SOBIK) study, which compared qualitative and quantitative neuroimaging findings in 72 children with complicated mild-to-severe TBI to 52 children with orthopedic injury (OI).
  
  
  METHODS
  Qualitative analyses of MRI scans coded white matter hyperintensities (WMHs), hemosiderin deposits reflecting prior hemorrhagic lesions, regions of encephalomalacia and/or atrophy, and corpus callosum atrophy and traumatic shear lesions. Two automated quantitative analyses were conducted: (a) FreeSurfer methods computed volumes for total brain, white matter (WM), gray matter (GM), corpus callosum, ventricles, amygdala, hippocampus, basal ganglia, and thalamus along with a ventricle-to-brain ratio (VBR); and (b) voxel-based morphometry (VBM) to identify WM, GM, and cerebrospinal fluid. We also examined performance on the Processing Speed Index (PSI) from the Wechsler Intelligence Scale for Children, Fourth Edition, in relation to the above-mentioned neuroimaging variables.
  
  
  RESULTS
  WMHs, hemosiderin deposits, and focal areas of encephalomalacia or atrophy were common in children with TBI, were related to injury severity, and were mostly observed within a frontotemporal distribution. Quantitative analyses showed volumetric changes related to injury severity, especially ventricular enlargement and reduced corpus callosum volume. VBM demonstrated similar findings, but, in addition, GM reductions in the inferior frontal, basal forebrain region, especially in the severe TBI group. The complicated mild TBI group showed few differences from the OI group. PSI was significantly associated with global atrophy, as measured by VBR.
  
  
  CONCLUSIONS
  MRI findings after childhood TBI are diverse and particularly influenced by injury severity, and they involve common features, group heterogeneity, and individual variability.
authors.affiliation: Department of Psychology and The Neuroscience Center, Brigham Young University, Provo, UT 84602, USA. erin_bigler@byu.edu
authors.forename: Erin D
authors.initials: ED
authors.lastname: Bigler
authors.forename: Tracy J
authors.initials: TJ
authors.lastname: Abildskov
authors.forename: Joann
authors.initials: J
authors.lastname: Petrie
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Farrer
authors.forename: Maureen
authors.initials: M
authors.lastname: Dennis
authors.forename: Nevena
authors.initials: N
authors.lastname: Simic
authors.forename: H Gerry
authors.initials: HG
authors.lastname: Taylor
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Rubin
authors.forename: Kathryn
authors.initials: K
authors.lastname: Vannatta
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Gerhardt
authors.forename: Terry
authors.initials: T
authors.lastname: Stancin
authors.forename: Keith
authors.initials: K
authors.lastname: Owen Yeates
mesh_terms: D001284:Atrophy / Q000209:etiology; D001921:Brain / Q000473:pathology*; D001930:Brain Injuries / Q000150:complications / Q000473:pathology* / Q000523:psychology; D001931:Brain Mapping; D002648:Child; D003337:Corpus Callosum / Q000473:pathology; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D009483:Neuropsychological Tests; D010372:Pediatrics; D012189:Retrospective Studies; D012920:Social Behavior Disorders / Q000209:etiology