title: Biexponential diffusion alterations in the normal-appearing white matter of glioma patients might indicate the presence of global vasogenic edema.
abstract: To investigate normal-appearing white matter (NAWM) microstructure of glioma patients with biexponential diffusion analysis in order to reveal the nature of diffusion abnormalities and to assess whether they are region-specific or global.
  
  
  
  Twenty-four newly diagnosed glioma patients (grade II-IV) and 24 matched control subjects underwent diffusion-weighted imaging at 3T. Diffusion parameters were calculated using monoexponential and biexponential models. Apparent diffusion coefficient (ADC) values were measured in the entire NAWM of the hemisphere contralateral and ipsilateral to the tumor. In the contralateral NAWM, regional ADC values were assessed in the frontal, parietal, occipital, and temporal NAWM.
  
  
  
  ADCmono and ADCfast were significantly higher than control values in all investigated regions except the temporal NAWM (P < 0.04). ADCslow was significantly increased in the total contralateral, frontal, and parietal NAWM (P < 0.03), while pslow was decreased in both total hemispheric NAWM and the parietal NAWM of glioma patients compared to controls (P < 0.04). ADCmono , ADCfast , ADCslow , and pslow were significantly different among the NAWM of the four lobes of the contralateral hemisphere in both groups (P < 0.0001), and these regional differences were similar in patients and controls (P > 0.05). Hemispheric ADCmono and pslow differences were different between groups (P < 0.05).
  
  
  
  Globally altered diffusion parameters suggest the presence of global vasogenic edema in the NAWM of glioma patients, which is further supported by the finding that regional differences in patients follow those found in controls. Alternatively, some tumor infiltration might contribute to diffusion abnormalities in the NAWM, especially in the tumor-affected hemisphere. J. Magn. Reson. Imaging 2016;44:633-641.
authors.affiliation: Diagnostic Center of Pécs, University of Pécs, Pécs, Hungary.|Department of Neurosurgery, University of Pécs, Pécs, Hungary.
authors.forename: Andrea
authors.initials: A
authors.lastname: Horváth
authors.affiliation: Diagnostic Center of Pécs, University of Pécs, Pécs, Hungary.|MTA - PTE, Clinical Neuroscience MR Research Group, Pécs, Hungary.
authors.forename: Gábor
authors.initials: G
authors.lastname: Perlaki
authors.affiliation: Diagnostic Center of Pécs, University of Pécs, Pécs, Hungary.|Department of Neurosurgery, University of Pécs, Pécs, Hungary.|Department of Radiology, University of Pécs, Pécs, Hungary.
authors.forename: Arnold
authors.initials: A
authors.lastname: Tóth
authors.affiliation: Diagnostic Center of Pécs, University of Pécs, Pécs, Hungary.|MTA - PTE, Clinical Neuroscience MR Research Group, Pécs, Hungary.
authors.forename: Gergely
authors.initials: G
authors.lastname: Orsi
authors.affiliation: Diagnostic Center of Pécs, University of Pécs, Pécs, Hungary.|MTA - PTE, Neurobiology of Stress Research Group, Pécs, Hungary.
authors.forename: Szilvia
authors.initials: S
authors.lastname: Nagy
authors.affiliation: Department of Neurosurgery, University of Pécs, Pécs, Hungary.|MTA - PTE, Clinical Neuroscience MR Research Group, Pécs, Hungary.
authors.forename: Tamás
authors.initials: T
authors.lastname: Dóczi
authors.affiliation: Department of Neurosurgery, University of Pécs, Pécs, Hungary.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Horváth
authors.affiliation: MTA - PTE, Clinical Neuroscience MR Research Group, Pécs, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Bogner
mesh_terms: D000328:Adult; D000465:Algorithms; D001929:Brain Edema / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology*; D001932:Brain Neoplasms / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D005260:Female; D005910:Glioma / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D066127:White Matter / Q000000981:diagnostic imaging / Q000473:pathology*
keywords: biexponential; diffusion weighted imaging; glioma; normal appearing white matter; tumor infiltration; vasogenic edema