Direct measurement of spin-lattice relaxation times of phosphorus metabolites in human myocardium.
T1 values of phosphorus metabolites visible in human cardiac 31P-MR spectra were determined in 12 volunteers at 1.5 T. Consecutive spectra were acquired with varying pulse repetition time (TR) from 1.6 to 24 s; volume selection was achieved with ISIS. T1's of creatine phosphate (CP), [gamma-P], [alpha-P], and [beta-P]ATP, 2-3 diphosphoglycerate, and phosphodiesters were 6.1 +/- 0.5, 5.4 +/- 0.5, 5.5 +/- 0.5, 5.8 +/- 1.0, 7.6 +/- 1.0, and 5.0 +/- 1.0 s, respectively. CP/ATP ratios showed little change with varying TR; linear regression of CP/ATP vs TR was of borderline significance (r = 0.28, P = 0.06). T1's for CP and ATP were also determined in standard solution (20 mM CP, 10 mM ATP) yielding T1CP of 8.7 +/- 0.2 and T1[gamma-P]-ATP of 9.9 +/- 0.7 s. Thus, T1's for CP and ATP were similar at 1.5 T in both human heart and standard solution. In human cardiac 31P-MR spectra, CP/ATP ratios may need little correction for partial saturation.
Neubauer
S
S
Department of Medicine, University of Würzburg, Germany.
Krahe
T
T
Schindler
R
R
Hillenbrand
H
H
Entzeroth
C
C
Horn
M
M
Bauer
W R
WR
Stephan
T
T
Lackner
K
K
Haase
A
A
D019794:2,3-Diphosphoglycerate; D000255:Adenosine Triphosphate / Q000032:analysis; D000328:Adult; D004163:Diphosphoglyceric Acids / Q000032:analysis; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D009206:Myocardium / Q000737:chemistry*; D010725:Phosphocreatine / Q000032:analysis; D010758:Phosphorus / Q000032:analysis / Q000378:metabolism*; D013997:Time Factors
D004163:Diphosphoglyceric Acids; D010725:Phosphocreatine; D019794:2,3-Diphosphoglycerate; D010758:Phosphorus; D000255:Adenosine Triphosphate