title: Localized 2D J-resolved 1H MR spectroscopy of human brain tumors in vivo.
abstract: Application of two-dimensional (2D) J-resolved MR spectroscopy, fully localized in three dimensions to monitor the metabolites in human brain tumors in vivo on a whole body MR scanner is presented. A modified PRESS sequence with [90 degrees - 180 degrees - t1/2 - 180 degrees - t1/ 2-acquisition] was used for voxel localization (2D J point-resolved spectroscopy [PRESS]); chemical shift selective (CHESS) sequence was used for suppression of water. The incremental delay (t1/2) added to the intervals before and after the last slice-selective 180 degrees RF pulse allowed the monitoring of the J-evolution in a localized 2D NMR spectrum. The addition of the second frequency dimension in 2D J-resolved spectroscopy to encode the indirect spin-spin coupling allowed the visualization of lactate peaks not observed in the 1D MR spectrum because of severe overlap with lipid peaks. 2D spectra of a two-layer phantom with 100 mM alanine and corn oil and also from three patients with tumors are presented here. The 2D spectra show that the J-coupled lactate peaks could be separated even when the lipids peaks severely overlap.
authors.affiliation: Department of Medical Physics, University of Wisconsin-Madison, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Thomas
authors.forename: L N
authors.initials: LN
authors.lastname: Ryner
authors.forename: M P
authors.initials: MP
authors.lastname: Mehta
authors.forename: P A
authors.initials: PA
authors.lastname: Turski
authors.forename: J A
authors.initials: JA
authors.lastname: Sorenson
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000503:physiopathology / Q000556:secondary; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D005909:Glioblastoma / Q000175:diagnosis / Q000503:physiopathology; D005910:Glioma / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D050356:Lipid Metabolism; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000503:physiopathology; D019047:Phantoms, Imaging