title: Diffusion tensor imaging evaluation of white matter in adolescents with myelomeningocele and Chiari II malformation.
abstract: BACKGROUND
  Macrostructural abnormalities in cerebral white matter in patients with myelomeningocele are well known, but microstructural abnormalities are not as well studied.
  
  
  OBJECTIVE
  The aim of this study was to evaluate cerebral white matter in adolescents with myelomeningocele using diffusion tensor imaging (DTI), and to investigate the effects of ventricular dilation and CSF shunt presence on white matter microstructure in these patients.
  
  
  METHODS
  DTI and T1-weighted 3-D (T1-3-D) MRI were performed on nine adolescents with myelomeningocele and Chiari II malformation and nine age-matched controls. The fractional anisotropy (FA) and mean diffusivity (MD) values were measured and compared.
  
  
  RESULTS
  Significantly decreased FA and increased MD values were observed in most white matter regions and fibers in adolescents with myelomeningocele compared to controls. Further analysis in patients revealed significant changes in DTI parameters in hemispheres with enlarged lateral ventricles compared to those with normal ventricle size. In addition, a significant difference in FA values in the posterior limb of the internal capsule was found in the comparison of hemispheres in patients with or without CSF shunt catheters.
  
  
  CONCLUSIONS
  This study revealed widespread microstructural abnormalities in white matter in adolescents with myelomeningocele and Chiari II malformation. Ventricular dilation may have additional effects on white matter microstructure in this patient population. CSF shunt diversion effects on white matter may be multifactorial and need further investigation.
authors: Department of Radiology, Arkansas Children's Hospital, Little Rock, AR 72202, USA. ouxiawei@uams.edu
authors: Xiawei
authors: X
authors: Ou
authors: Charles M
authors: CM
authors: Glasier
authors: Jeffrey H
authors: JH
authors: Snow
mesh_terms: D000293:Adolescent; D001139:Arnold-Chiari Malformation / Q000175:diagnosis*; D001921:Brain / Q000002:abnormalities*; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D008297:Male; D008591:Meningomyelocele / Q000175:diagnosis*; D012015:Reference Standards