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Direct in vivo measurement of human cerebral GABA concentration using MEGA‐editing at 7 Tesla
Author(s) -
Terpstra Melissa,
Ugurbil Kamil,
Gruetter Rolf
Publication year - 2002
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.10146
Subject(s) - in vivo , signal (programming language) , contamination , chemistry , nuclear magnetic resonance , creatine , analytical chemistry (journal) , computer science , physics , chromatography , biochemistry , biology , microbiology and biotechnology , ecology , programming language
Spectral editing of the GABA spin system is hampered by coediting of macromolecule (MM) coherences. To reduce contamination arising from MMs in spectra edited for GABA, the highest field strength currently available for human experimentation (7 Tesla) and MEGA‐based editing were used. Despite judicious choice of experimental parameters, MM contamination was found to arise from field drifts. When the MM contribution was accounted for, [GABA] = 0.75 ± 0.14 μmol/g (mean ± SD, N = 16) relative to 8 μmol/g creatine (Cr), whereas without accounting for the MM signal [GABA*] = 0.88 ± 0.23 μmol/g (mean ± SD, N = 16). Incorporating the direct experimental assessment of MM contamination to the edited GABA signal substantially reduced the variance of the measurement, resulting in concentrations that were in excellent agreement with previous 13 C labeling experiments. Magn Reson Med 47:1009–1012, 2002. © 2002 Wiley‐Liss, Inc.