title: Regional metabolite T2 in the healthy rhesus macaque brain at 7T.
abstract: Although the rhesus macaque brain is an excellent model system for the study of neurological diseases and their responses to treatment, its small size requires much higher spatial resolution, motivating use of ultra-high-field (B(0)) imagers. Their weaker radio-frequency fields, however, dictate longer pulses; hence longer TE localization sequences. Due to the shorter transverse relaxation time (T(2)) at higher B(0)s, these longer TEs subject metabolites to T(2)-weighting, that decrease their quantification accuracy. To address this we measured the T(2)s of N-acetylaspartate (NAA), choline (Cho), and creatine (Cr) in several gray matter (GM) and white matter (WM) regions of four healthy rhesus macaques at 7T using three-dimensional (3D) proton MR spectroscopic imaging at (0.4 cm)(3) = 64 mul spatial resolution. The results show that macaque T(2)s are in good agreement with those reported in humans at 7T: 169 +/- 2.3 ms for NAA (mean +/- SEM), 114 +/- 1.9 ms for Cr, and 128 +/- 2.4 ms for Cho, with no significant differences between GM and WM. The T(2) histograms from 320 voxels in each animal for NAA, Cr, and Cho were similar in position and shape, indicating that they are potentially characteristic of "healthy" in this species.
authors.affiliation: Department of Radiology, New York University School of Medicine, New York, New York, USA.
authors.forename: Songtao
authors.initials: S
authors.lastname: Liu
authors.forename: Oded
authors.initials: O
authors.lastname: Gonen
authors.forename: Lazar
authors.initials: L
authors.lastname: Fleysher
authors.forename: Roman
authors.initials: R
authors.lastname: Fleysher
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Soher
authors.forename: Sarah
authors.initials: S
authors.lastname: Pilkenton
authors.forename: Margaret R
authors.initials: MR
authors.lastname: Lentz
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Ratai
authors.forename: R Gilberto
authors.initials: RG
authors.lastname: González
mesh_terms: D000818:Animals; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D001931:Brain Mapping / Q000379:methods*; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D005260:Female; D007091:Image Processing, Computer-Assisted; D008253:Macaca mulatta; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline