title: Spin-echo methods for the determination of 31P transverse relaxation times of the ATP NMR signals in vivo.
abstract: 31P magnetic resonance spectroscopy (MRS) examinations of the calf muscles of healthy volunteers were performed to determine T2 of the coupled ATP signals by use of the Hahn spin-echo and the frequency-selective spin-echo method. Additional measurements with the J-coupling refocused double echo are presented. The most reliable determination of T2 relaxation times is possible with the frequency-selective spin echo. The other methods yield substantially wrong results. Theoretical explanations are given how J-coupling and pulse-angle deviations affect the signals and therefore the T2 determinations. The calculations for a weakly coupled homonuclear AX spin system are shown because they demonstrate most of the relevant facts. In addition, some important results for a homonuclear AMX spin system, which the ATP is considered to be, are given.
authors.affiliation: Institute of Physics, University of Tübingen, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Straubinger
authors.forename: W I
authors.initials: WI
authors.lastname: Jung
authors.forename: M
authors.initials: M
authors.lastname: Bunse
authors.forename: O
authors.initials: O
authors.lastname: Lutz
authors.forename: K
authors.initials: K
authors.lastname: Küper
authors.forename: G
authors.initials: G
authors.lastname: Dietze
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D006801:Humans; D007866:Leg; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009132:Muscles / Q000378:metabolism*
chemical_list: D000255:Adenosine Triphosphate