title: T2 measurement of J-coupled metabolites in the human brain at 3T.
abstract: Proton T(2) relaxation times of metabolites in the human brain were measured using point resolved spectroscopy at 3T in vivo. Four echo times (54, 112, 246 and 374 ms) were selected from numerical and phantom analyses for effective detection of the glutamate multiplet at ~ 2.35 ppm. In vivo data were obtained from medial and left occipital cortices of five healthy volunteers. The cortices contained predominantly gray and white matter, respectively. Spectra were analyzed with LCModel software using volume-localized calculated spectra of brain metabolites. The estimate of the signal strength vs. TE was fitted to a monoexponential function for estimation of apparent T(2) (T(2)(†)). T(2)(†) was estimated to be similar between the brain regions for creatine, choline, glutamate and myo-inositol, but significantly different for N-acetylaspartate singlet and multiplet. T(2)(†)s of glutamate and myo-inositol were measured as 181 ± 16 and 197 ± 14 ms (mean ± SD, N = 5) for medial occipital cortices, and 180 ± 12 and 196 ± 17 ms for left occipital cortices, respectively.
authors.affiliation: Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
authors.forename: Sandeep K
authors.initials: SK
authors.lastname: Ganji
authors.forename: Abhishek
authors.initials: A
authors.lastname: Banerjee
authors.forename: Aditya M
authors.initials: AM
authors.lastname: Patel
authors.forename: Yan D
authors.initials: YD
authors.lastname: Zhao
authors.forename: Ivan E
authors.initials: IE
authors.lastname: Dimitrov
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Browning
authors.forename: E Sherwood
authors.initials: ES
authors.lastname: Brown
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Maher
authors.forename: Changho
authors.initials: C
authors.lastname: Choi
mesh_terms: D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D003404:Creatinine / Q000032:analysis*; D018698:Glutamic Acid / Q000032:analysis*; D006801:Humans; D007294:Inositol / Q000032:analysis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014018:Tissue Distribution
chemical_list: D001224:Aspartic Acid; D018698:Glutamic Acid; D007294:Inositol; C000179:N-acetylaspartate; D003404:Creatinine