title: Tissue specific resonance frequencies of water and metabolites within the human brain.
abstract: Chemical shift imaging (CSI) without water suppression was used to examine tissue-specific resonance frequencies of water and metabolites within the human brain. The aim was to verify if there are any regional differences in those frequencies and to determine the influence of chemical shift displacement in slice-selection direction. Unsuppressed spectra were acquired at 3T from nine subjects. Resonance frequencies of water and after water signal removal of total choline, total creatine and NAA were estimated. Furthermore, frequency distances between the water and those resonances were calculated. Results were corrected for chemical shift displacement. Frequency distances between water and metabolites were consistent and greater for GM than for WM. The highest value of WM to GM difference (14ppb) was observed for water to NAA frequency distance. This study demonstrates that there are tissue-specific differences between frequency distances of water and metabolites. Moreover, the influence of chemical shift displacement in slice-selection direction is showed to be negligible.
authors.affiliation: MR Research Group, Department of Diagnostic and Interventional Neuroradiology, University Hospital Tuebingen, Hoppe-Seyler strasse 3, 72076 Tuebingen, Germany. grzegorz.chadzynski@med.uni-tuebingen.de
authors.forename: Grzegorz L
authors.initials: GL
authors.lastname: Chadzynski
authors.forename: Benjamin
authors.initials: B
authors.lastname: Bender
authors.forename: Adriane
authors.initials: A
authors.lastname: Groeger
authors.forename: Michael
authors.initials: M
authors.lastname: Erb
authors.forename: Uwe
authors.initials: U
authors.lastname: Klose
mesh_terms: D000328:Adult; D000465:Algorithms; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000737:chemistry; D001921:Brain / Q000033:anatomy & histology*; D001923:Brain Chemistry; D002794:Choline / Q000737:chemistry; D003404:Creatinine / Q000737:chemistry; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D019047:Phantoms, Imaging; D014867:Water / Q000737:chemistry*; D055815:Young Adult
chemical_list: D014867:Water; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003404:Creatinine; D002794:Choline