In vivo estimation of transverse relaxation time constant (T2) of 17 human brain metabolites at 3T

PurposeThe transverse relaxation times T-2 of 17 metabolites in vivo at 3T is reported and region specific differences are addressed. MethodsAn echo-time series protocol was applied to one, two, or three volumes of interest with different fraction of white and gray matter including a total number of 106 healthy volunteers and acquiring a total number of 128 spectra. The data were fitted with the 2D fitting tool ProFit2, which included individual line shape modeling for all metabolites and allowed the T-2 calculation of 28 moieties of 17 metabolites. ResultsThe T-2 of 10 metabolites and their moieties have been reported for the first time. Region specific T-2 differences in white and gray matter enriched tissue occur in 16 of 17 metabolites examined including single resonance lines and coupled spin systems. ConclusionThe relaxation time T-2 is regions specific and has to be considered when applying tissue composition correction for internal water referencing. Magn Reson Med 80:452-461, 2018. (c) 2018 International Society for Magnetic Resonance in Medicine.