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Relaxation times of 31 P‐metabolites in human calf muscle at 3 T
Author(s) -
Meyerspeer Martin,
Krššák Martin,
Moser Ewald
Publication year - 2003
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.10426
Subject(s) - relaxation (psychology) , spin–lattice relaxation , human muscle , metabolite , chemistry , nuclear magnetic resonance , t2 relaxation , calf muscle , in vivo , muscle relaxation , spin–spin relaxation , skeletal muscle , magnetic resonance imaging , anatomy , medicine , biology , biochemistry , physics , microbiology and biotechnology , radiology , nuclear quadrupole resonance
Localized 31 P‐STEAM experiments were performed at 3 T to estimate relaxation times of phosphorus‐containing metabolites in the human calf muscle in vivo. T 1 and T 2 times of PCr, P i , and NTPs were measured in the resting calf muscle of healthy subjects by varying TR and TE. The localization performance of the 31 P‐STEAM sequence was evaluated on a test object, resulting in a relative selection efficiency of 78 ± 1% and contamination from outside the voxel of 0 ± 2% under fully relaxed conditions. T 1 relaxation times (±SD, n = 5) of P i , PCr, γ‐NTP, α‐NTP, and β‐NTP obtained at 3 T are 5.2 ± 1.0 s, 6.4 ± 0.2 s, 4.5 ± 0.3 s, 2.6 ± 0.9 s, and 3.5 ± 1.1 s, respectively. T 2 relaxation times (±SD, n = 6) of these metabolites are 148 ± 17 ms, 334 ± 30 ms, 78 ± 13 ms, 55 ± 7 ms, and 55 ± 10 ms, respectively. Spin‐lattice relaxation times established at 3 T are consistent with literature data at lower field strengths, whereas spin–spin relaxation times are lower. Several methodological considerations are discussed which may help improve quantification of metabolite concentrations in the human (calf) muscle in vivo by using localized noninvasive 31 P‐MRS at 3 T, which is currently being tested for routine clinical applications. Magn Reson Med 49:620–625, 2003. © 2003 Wiley‐Liss, Inc.