title: Gliomas: diffusion kurtosis MR imaging in grading.
abstract: OBJECTIVE
  To assess the diagnostic accuracy of diffusion kurtosis magnetic resonance imaging parameters in grading gliomas.
  
  
  METHODS
  The institutional review board approved this prospective study, and informed consent was obtained from all patients. Diffusion parameters-mean diffusivity (MD), fractional anisotropy (FA), mean kurtosis, and radial and axial kurtosis-were compared in the solid parts of 17 high-grade gliomas and 11 low-grade gliomas (P<.05 significance level, Mann-Whitney-Wilcoxon test, Bonferroni correction). MD, FA, mean kurtosis, radial kurtosis, and axial kurtosis in solid tumors were also normalized to the corresponding values in contralateral normal-appearing white matter (NAWM) and the contralateral posterior limb of the internal capsule (PLIC) after age correction and were compared among tumor grades.
  
  
  RESULTS
  Mean, radial, and axial kurtosis were significantly higher in high-grade gliomas than in low-grade gliomas (P = .02, P = .015, and P = .01, respectively). FA and MD did not significantly differ between glioma grades. All values, except for axial kurtosis, that were normalized to the values in the contralateral NAWM were significantly different between high-grade and low-grade gliomas (mean kurtosis, P = .02; radial kurtosis, P = .03; FA, P = .025; and MD, P = .03). When values were normalized to those in the contralateral PLIC, none of the considered parameters showed significant differences between high-grade and low-grade gliomas. The highest sensitivity and specificity for discriminating between high-grade and low-grade gliomas were found for mean kurtosis (71% and 82%, respectively) and mean kurtosis normalized to the value in the contralateral NAWM (100% and 73%, respectively). Optimal thresholds for mean kurtosis and mean kurtosis normalized to the value in the contralateral NAWM for differentiating high-grade from low-grade gliomas were 0.52 and 0.51, respectively.
  
  
  CONCLUSIONS
  There were significant differences in kurtosis parameters between high-grade and low-grade gliomas; hence, better separation was achieved with these parameters than with conventional diffusion imaging parameters.
authors.affiliation: Department of Radiology, University Hospitals of Leuven, Leuven, Belgium.
authors.forename: Sofie
authors.initials: S
authors.lastname: Van Cauter
authors.forename: Jelle
authors.initials: J
authors.lastname: Veraart
authors.forename: Jan
authors.initials: J
authors.lastname: Sijbers
authors.forename: Ronald R
authors.initials: RR
authors.lastname: Peeters
authors.forename: Uwe
authors.initials: U
authors.lastname: Himmelreich
authors.forename: Frederik
authors.initials: F
authors.lastname: De Keyzer
authors.forename: Stefaan W
authors.initials: SW
authors.lastname: Van Gool
authors.forename: Frank
authors.initials: F
authors.lastname: Van Calenbergh
authors.forename: Steven
authors.initials: S
authors.lastname: De Vleeschouwer
authors.forename: Wim
authors.initials: W
authors.lastname: Van Hecke
authors.forename: Stefan
authors.initials: S
authors.lastname: Sunaert
mesh_terms: D000328:Adult; D000368:Aged; D016880:Anisotropy; D019540:Area Under Curve; D001932:Brain Neoplasms / Q000473:pathology*; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005910:Glioma / Q000473:pathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D060787:Neoplasm Grading; D009942:Organometallic Compounds; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; C072417:gadoterate meglumine