title: Metabolite kinetics in C6 rat glioma model using magnetic resonance spectroscopic imaging of hyperpolarized [1-(13)C]pyruvate.
abstract: In addition to an increased lactate-to-pyruvate ratio, altered metabolism of a malignant glioma can be further characterized by its kinetics. Spatially resolved dynamic data of pyruvate and lactate from C6-implanted female Sprague-Dawley rat brain were acquired using a spiral chemical shift imaging sequence after a bolus injection of a hyperpolarized [1-(13)C]pyruvate. Apparent rate constants for the conversion of pyruvate to lactate in three different regions (glioma, normal appearing brain, and vasculature) were estimated based on a two-site exchange model. The apparent conversion rate constant was 0.018 ± 0.004 s(-1) (mean ± standard deviation, n = 6) for glioma, 0.009 ± 0.003 s(-1) for normal brain, and 0.005 ± 0.001 s(-1) for vasculature, whereas the lactate-to-pyruvate ratio, the metabolic marker used to date to identify tumor regions, was 0.36 ± 0.07 (mean ± SD), 0.24 ± 0.07, and 0.12 ± 0.02 for glioma, normal brain, and vasculature, respectively. The data suggest that the apparent conversion rate better differentiate glioma from normal brain (P = 0.001, n = 6) than the lactate-to-pyruvate ratio (P = 0.02).
authors.affiliation: Department of Electrical Engineering, Stanford University, Stanford, California, USA. jaemo@stanford.edu
authors.forename: Jae Mo
authors.initials: JM
authors.lastname: Park
authors.forename: Sonal
authors.initials: S
authors.lastname: Josan
authors.forename: Taichang
authors.initials: T
authors.lastname: Jang
authors.forename: Milton
authors.initials: M
authors.lastname: Merchant
authors.forename: Yi-Fen
authors.initials: YF
authors.lastname: Yen
authors.forename: Ralph E
authors.initials: RE
authors.lastname: Hurd
authors.forename: Lawrence
authors.initials: L
authors.lastname: Recht
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Spielman
authors.forename: Dirk
authors.initials: D
authors.lastname: Mayer
mesh_terms: D000818:Animals; D001932:Brain Neoplasms / Q000378:metabolism* / Q000473:pathology; D002247:Carbon Isotopes / Q000493:pharmacokinetics; D045744:Cell Line, Tumor; D005260:Female; D005910:Glioma / Q000175:diagnosis / Q000378:metabolism*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008657:Metabolic Clearance Rate; D019289:Pyruvic Acid / Q000032:analysis / Q000378:metabolism*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D002247:Carbon Isotopes; D019275:Radiopharmaceuticals; D019289:Pyruvic Acid