title: Surface-to-volume ratio mapping of tumor microstructure using oscillating gradient diffusion weighted imaging.
abstract: To disentangle the free diffusivity (D0 ) and cellular membrane restrictions, by means of their surface-to-volume ratio (S/V), using the frequency-dependence of the diffusion coefficient D(ω), measured in brain tumors in the short diffusion-time regime using oscillating gradients (OGSE).
  
  
  
  In vivo and ex vivo OGSE experiments were performed on mice bearing the GL261 murine glioma model (n = 10) to identify the relevant time/frequency (t/ω) domain where D(ω) linearly decreases with ω(-1/2) . Parametric maps (S/V, D0 ) are compared with conventional DWI metrics. The impact of frequency range and temperature (20°C versus 37°C) on S/V and D0 is investigated ex vivo.
  
  
  
  The validity of the short diffusion-time regime is demonstrated in vivo and ex vivo. Ex vivo measurements confirm that the purely geometric restrictions embodied in S/V are independent from temperature and frequency range, while the temperature dependence of the free diffusivity D0 is similar to that of pure water.
  
  
  
  Our results suggest that D(ω) in the short diffusion-time regime can be used to uncouple the purely geometric restriction effect, such as S/V, from the intrinsic medium diffusivity properties, and provides a nonempirical and objective way to interpret frequency/time-dependent diffusion changes in tumors in terms of objective biophysical tissue parameters. Magn Reson Med 76:237-247, 2016. © 2015 Wiley Periodicals, Inc.
authors.affiliation: Center for Advanced Imaging Innovation and Research (CAI2R), New York, New York, USA.|Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.
authors.forename: Olivier
authors.initials: O
authors.lastname: Reynaud
authors.affiliation: Center for Advanced Imaging Innovation and Research (CAI2R), New York, New York, USA.|Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.
authors.forename: Kerryanne Veronica
authors.initials: KV
authors.lastname: Winters
authors.affiliation: Center for Advanced Imaging Innovation and Research (CAI2R), New York, New York, USA.|Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.
authors.forename: Dung Minh
authors.initials: DM
authors.lastname: Hoang
authors.affiliation: Center for Advanced Imaging Innovation and Research (CAI2R), New York, New York, USA.|Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.
authors.forename: Youssef Zaim
authors.initials: YZ
authors.lastname: Wadghiri
authors.affiliation: Center for Advanced Imaging Innovation and Research (CAI2R), New York, New York, USA.|Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.
authors.forename: Dmitry S
authors.initials: DS
authors.lastname: Novikov
authors.affiliation: Center for Advanced Imaging Innovation and Research (CAI2R), New York, New York, USA.|Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.
authors.forename: Sungheon Gene
authors.initials: SG
authors.lastname: Kim
mesh_terms: D000465:Algorithms; D000818:Animals; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D045744:Cell Line, Tumor; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging* / Q000473:pathology*; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D051379:Mice; D008807:Mice, Inbred BALB C; D009991:Oscillometry / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D047368:Tumor Burden
keywords: diffusion time-dependence; glioma; mitra limit; oscillating gradients spin echo; restrictions; surface-to-volume