title: Dynamically shimmed multivoxel 1H magnetic resonance spectroscopy and multislice magnetic resonance spectroscopic imaging of the human brain.
abstract: In vivo multivoxel Magnetic Resonance Spectroscopy (MRS) and multislice Magnetic Resonance Spectroscopic Imaging (MRSI) are extremely susceptible to poor homogeneity of the static magnetic field. Existing room-temperature (RT) shim technology can adequately optimize the B(0) homogeneity of local volumes, such as single voxels. However, the widespread global homogeneity required for in vivo spectral acquisitions from multiple volumes in the human brain cannot be attained with a single RT shim setting. Dynamic shim updating (DSU) allows for use of local RT shim B(0) homogeneity compensation capabilities in a global fashion. Here, by updating first- and second-order shims on a voxel- and slice-specific basis using a pre-emphasized DSU system, we present multivoxel MRS and multislice MRSI of the human brain. These results demonstrate that DSU can increase multivoxel MRS acquisition capabilities and significantly improve the quality of multislice MRSI data.
authors.affiliation: Yale Magnetic Resonance Research Center, New Haven, Connecticut 06520-8043, USA. kevin.koch@yale.edu
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Koch
authors.forename: Laura I
authors.initials: LI
authors.lastname: Sacolick
authors.forename: Terence W
authors.initials: TW
authors.lastname: Nixon
authors.forename: Scott
authors.initials: S
authors.lastname: McIntyre
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Rothman
authors.forename: Robin A
authors.initials: RA
authors.lastname: de Graaf
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged