title: Abnormalities in the normal appearing white matter of the cerebral hemisphere contralateral to a malignant brain tumor detected by diffusion tensor imaging.
abstract: BACKGROUND
  Malignant brain tumors tend to migration and invasion of surrounding brain tissue. Histopathological studies reported malignant cells in macroscopically unsuspicious parenchyma (normal appearing white matter - NAWM) remote from the tumor localization. In early stages, diffuse interneural infiltration with changes of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) is hypothesized.
  
  
  METHODS
  Patients' ADC and FA values from NAWM of the hemisphere contralateral to a malignant glioma were compared to age- and sex-matched normal controls.
  
  
  RESULTS
  Apparent diffusion coefficient levels of the entire contralateral hemisphere revealed a significant increase and a decrease of FA levels. An even more pronounced ADC increase was found in a region mirroring the glioma location.
  
  
  CONCLUSIONS
  In patients with previously untreated anaplastic astrocytoma or glioblastoma, an increase of the ADC and a reduction of FA were found in the brain parenchyma of the hemisphere contralateral to the tumor localization. In the absence of visible MRI abnormalities, this may be an early indicator of microstructural changes of the NAWM attributed to malignant brain tumor.
authors.affiliation: Dr. Kai Kallenberg, Institut für Diagnostische und Interventionelle Neuroradiologie, Universitätsmedizin Göttingen, Postfach, 37099 Göttingen, Germany, e-mail: kai.kallenberg@med.uni-goettingen.de.
authors.forename: Kai
authors.initials: K
authors.lastname: Kallenberg
authors.forename: Torben
authors.initials: T
authors.lastname: Goldmann
authors.forename: Jan
authors.initials: J
authors.lastname: Menke
authors.forename: Herwig
authors.initials: H
authors.lastname: Strik
authors.forename: Hans C
authors.initials: HC
authors.lastname: Bock
authors.forename: Alexander
authors.initials: A
authors.lastname: Mohr
authors.forename: Jan H
authors.initials: JH
authors.lastname: Buhk
authors.forename: Jens
authors.initials: J
authors.lastname: Frahm
authors.forename: Peter
authors.initials: P
authors.lastname: Dechent
authors.forename: Michael
authors.initials: M
authors.lastname: Knauth
mesh_terms: D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000473:pathology*; D001932:Brain Neoplasms / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D005260:Female; D007839:Functional Laterality; D005909:Glioblastoma / Q000473:pathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D066127:White Matter / Q000473:pathology*; D055815:Young Adult