title: Increased diffusion in the normal appearing white matter of brain tumor patients: is this just tumor infiltration?
abstract: Altered diffusion in the normal appearing white matter (NAWM) of glioma patients has been explained by tumor infiltration. The goal of the present study was to test this explanation indirectly by examining whether these alterations were also present in the contralateral NAWM of non-infiltrative tumors like meningiomas; and to search for other possible reasons for this abnormality. Twenty-seven patients with histologically verified glioma (grade II-IV), 22 meningioma patients and two groups of age- and sex-matched healthy controls underwent diffusion weighted imaging (DWI) on a 3T MR. All patients were examined before treatment. Apparent diffusion coefficient (ADC) values were calculated in the entire NAWM of the hemisphere contralateral to the tumor. ADC values of the NAWM were compared between groups with Mann-Whitney U-test and multiple linear regression. The relations of ADC in NAWM to glioma grade and to tumor volume were also investigated. ADC values of the contralateral NAWM were significantly higher in both glioma and meningioma patients compared to controls (P = 0.0006 and 0.0099, respectively). ADC value was higher in the NAWM of high grade gliomas than in low grade gliomas (P = 0.0181) and in healthy control subjects (P = 0.0003). ADC did not depend on tumor volume in any of the patient groups. Elevated ADC in the NAWM of both glioma and meningioma patients might indicate that the effect of infiltrating tumor cells is not the only reason for the alteration as it has been previously suggested. Although the role of mass effect was not proved, other mechanisms might also contribute to ADC elevation.
authors.affiliation: Diagnostic Center of Pécs, 2. Rét st., Pécs, 7623, Hungary.|Department of Neurosurgery, University of Pécs, Pécs, Hungary.
authors.forename: Andrea
authors.initials: A
authors.lastname: Horváth
authors.affiliation: Diagnostic Center of Pécs, 2. Rét st., Pécs, 7623, 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, 2. Rét st., Pécs, 7623, 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, 2. Rét st., Pécs, 7623, 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, 2. Rét st., Pécs, 7623, 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: Diagnostic Center of Pécs, 2. Rét st., Pécs, 7623, Hungary. peter.bogner@gmail.com.|Department of Radiology, University of Pécs, Pécs, Hungary. peter.bogner@gmail.com.
authors.forename: Péter
authors.initials: P
authors.lastname: Bogner
mesh_terms: D001932:Brain Neoplasms / Q000473:pathology*; D016022:Case-Control Studies; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D066127:White Matter / Q000473:pathology*
keywords: ADC; Glioma; Infiltration; Meningioma; Normal appearing white matter