title: 7-T (1) H MRS with adiabatic refocusing at short TE using radiofrequency focusing with a dual-channel volume transmit coil.
abstract: In vivo MRS of the human brain at ultrahigh field allows for the identification of a large number of metabolites at higher spatial resolutions than currently possible in clinical practice. However, the in vivo localization of single-voxel spectroscopy has been shown to be challenging at ultrahigh field because of the low bandwidth of refocusing radiofrequency (RF) pulses. Thus far, the proposed methods for localized MRS at 7 T suffer from long TE, inherent signal loss and/or a large chemical shift displacement artifact that causes a spatial displacement between resonances, and results in a decreased efficiency in editing sequences. In this work, we show that, by driving a standard volume coil with two RF amplifiers, focusing the B 1+ field in a certain location and using high-bandwidth adiabatic refocusing pulses, a semi-LASER (semi-localized by adiabatic selective refocusing) localization is feasible at short TE in the human brain with full signal acquisition and a low chemical shift displacement artifact at 7 T.
authors.affiliation: Department of Radiology, University Medical Center Utrecht, the Netherlands.
authors.forename: V O
authors.initials: VO
authors.lastname: Boer
authors.forename: A L H M W
authors.initials: AL
authors.lastname: van Lier
authors.forename: J M
authors.initials: JM
authors.lastname: Hoogduin
authors.forename: J P
authors.initials: JP
authors.lastname: Wijnen
authors.forename: P R
authors.initials: PR
authors.lastname: Luijten
authors.forename: D W J
authors.initials: DW
authors.lastname: Klomp
mesh_terms: D000042:Absorption; D003198:Computer Simulation; D004574:Electromagnetic Fields; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation* / Q000379:methods*; D055442:Metabolome; D011522:Protons; D011846:Radio Waves; D013113:Spin Labels
chemical_list: D011522:Protons; D013113:Spin Labels