title: Out-and-in spiral spectroscopic imaging in rat brain at 7 T.
abstract: With standard spectroscopic imaging, high spatial resolution is achieved at the price of a large number of phase-encoding steps, leading to long acquisition times. Fast spatial encoding methods reduce the minimum total acquisition time. In this article, a k-space scanning scheme using a continuous series of growing and shrinking, or "out-and-in," spiral trajectories is implemented and the feasibility of spiral spectroscopic imaging for animal models at high B(0) field is demonstrated. This method was applied to rat brain at 7 T. With a voxel size of about 8.7 microl (as calculated from the point-spread function), a 30 x 30 matrix, and a spectral bandwidth of 11 kHz, the minimum scan time was 9 min 20 sec for a signal-to-noise ratio of 7.1 measured on the N-acetylaspartate peak.
authors.affiliation: Laboratoire mixte INSERM U594 / Université Joseph Fourier Neuroimagerie fonctionnelle et métabolique, Laboratoire de Recherche Conventionné (30V) du CEA, Centre Hospitalier Universitaire, Grenoble, France.
authors.forename: Bassem
authors.initials: B
authors.lastname: Hiba
authors.forename: Bérengère
authors.initials: B
authors.lastname: Faure
authors.forename: Laurent
authors.initials: L
authors.lastname: Lamalle
authors.forename: Michel
authors.initials: M
authors.lastname: Décorps
authors.forename: Anne
authors.initials: A
authors.lastname: Ziegler
mesh_terms: D000818:Animals; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D001921:Brain / Q000033:anatomy & histology; D001923:Brain Chemistry; D002794:Choline / Q000032:analysis; D003401:Creatine / Q000032:analysis; D018698:Glutamic Acid / Q000032:analysis; D005973:Glutamine / Q000032:analysis; D007091:Image Processing, Computer-Assisted; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D051381:Rats; D017208:Rats, Wistar
chemical_list: D005973:Glutamine; D001224:Aspartic Acid; D018698:Glutamic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline