title: In vivo differentiation of N-acetyl aspartyl glutamate from N-acetyl aspartate at 3 Tesla.
abstract: A method is described that allows the in vivo differentiation of N-acetyl aspartate (NAA) from N-acetyl aspartyl glutamate (NAAG) by in vivo MR spectroscopy (MRS) at 3 Tesla (3T). The method, which is based on MEGA-point-resolved spectroscopy (PRESS) editing, selectively targets the aspartyl spin system of one species while deliberately removing the other species from the spectrum. This allows quantitative measurements of NAA and NAAG without the need for fitting of unresolved peaks. White matter concentrations of NAA (6.7 +/- 0.3 mM) and NAAG (2.2 +/- 0.3 mM) were measured in 10 healthy volunteers to demonstrate the method.
authors.affiliation: Russell H Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
authors.forename: Richard A E
authors.initials: RA
authors.lastname: Edden
authors.forename: Martin G
authors.initials: MG
authors.lastname: Pomper
authors.forename: Peter B
authors.initials: PB
authors.lastname: Barker
mesh_terms: D000328:Adult; D016477:Artifacts; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D001923:Brain Chemistry; D004151:Dipeptides / Q000737:chemistry* / Q000378:metabolism; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D019047:Phantoms, Imaging
chemical_list: D004151:Dipeptides; C027172:isospaglumic acid; D001224:Aspartic Acid; C000179:N-acetylaspartate