title: The role of diffusion-weighted magnetic resonance imaging in pediatric brain tumors.
abstract: OBJECTIVE
  Diffusion-weighted imaging (DWI) may enhance the radiographic diagnosis of pediatric brain tumors. This study reviews the DWI properties of pediatric brain tumors at our institution and examines their relationship to tumor grade and type.
  
  
  METHODS
  The preoperative DWI and apparent diffusion coefficient (ADC) characteristics of brain tumors in 41 children were compared with histologic diagnosis. Signal characteristics on DWI and ADC maps correlated well with tumor grade. High-grade lesions were hyperintense on DWI and hypointense on ADC maps. Sensitivity, specificity, positive predictive value, and negative predictive value were 70, 100, 100, and 91%, respectively. Signal characteristics did not differ among different tumors of the same grade. All primitive neuroectodermal tumors showed diffusion restriction whereas none of the ependymomas did.
  
  
  CONCLUSIONS
  The signal characteristics on DWI and ADC maps appeared to be strongly correlated to grade in pediatric brain tumors and they may assist with preoperative diagnostic predictions.
authors.affiliation: Department of Neurosurgery, Primary Children's Medical Center, University of Utah School of Medicine, Salt Lake City, UT 84113, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Kan
authors.forename: James K
authors.initials: JK
authors.lastname: Liu
authors.forename: Gary
authors.initials: G
authors.lastname: Hedlund
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Brockmeyer
authors.forename: Marion L
authors.initials: ML
authors.lastname: Walker
authors.forename: John R W
authors.initials: JR
authors.lastname: Kestle
mesh_terms: D001932:Brain Neoplasms / Q000175:diagnosis*; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D010372:Pediatrics