RT Journal Article SR Electronic T1 Improved Brain Tumor Classification by Sodium MR Imaging: Prediction of IDH Mutation Status and Tumor Progression JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 66 OP 73 DO 10.3174/ajnr.A4493 VO 37 IS 1 A1 A. Biller A1 S. Badde A1 A. Nagel A1 J.-O. Neumann A1 W. Wick A1 A. Hertenstein A1 M. Bendszus A1 F. Sahm A1 N. Benkhedah A1 J. Kleesiek YR 2016 UL http://www.ajnr.org/content/37/1/66.abstract AB BACKGROUND AND PURPOSE: MR imaging in neuro-oncology is challenging due to inherent ambiguities in proton signal behavior. Sodium-MR imaging may substantially contribute to the characterization of tumors because it reflects the functional status of the sodium-potassium pump and sodium channels.MATERIALS AND METHODS: Sodium-MR imaging data of patients with treatment-naïve glioma WHO grades I–IV (n = 34; mean age, 51.29 ± 17.77 years) were acquired by using a 7T MR system. For acquisition of sodium-MR images, we applied density-adapted 3D radial projection reconstruction pulse sequences. Proton-MR imaging data were acquired by using a 3T whole-body system.RESULTS: We demonstrated that the initial sodium signal of a treatment-naïve brain tumor is a significant predictor of isocitrate dehydrogenase (IDH) mutation status (P < .001). Moreover, independent of this correlation, the Cox proportional hazards model confirmed the sodium signal of treatment-naïve brain tumors as a predictor of progression (P = .003). Compared with the molecular signature of IDH mutation status, information criteria of model comparison revealed that the sodium signal is even superior to IDH in progression prediction. In addition, sodium-MR imaging provides a new approach to noninvasive tumor classification. The sodium signal of contrast-enhancing tumor portions facilitates differentiation among most glioma types (P < .001).CONCLUSIONS: The information of sodium-MR imaging may help to classify neoplasias at an early stage, to reduce invasive tissue characterization such as stereotactic biopsy specimens, and overall to promote improved and individualized patient management in neuro-oncology by novel imaging signatures of brain tumors.AAanaplastic astrocytomaCEcontrast-enhancingGBglioblastomaGGgangliogliomaIDHisocitrate dehydrogenaseNaRrelaxation-weighted sodium signalNaTtotal sodium signalPApilocytic astrocytomaPFSprogression-free survivalPHproportional hazardWHOWorld Health Organization