Direct measurements of relaxation times of phosphorus metabolites in the human myocardium
Schindler R., Krahe T., Neubauer S., Hillenbrand H., Entzeroth C., Horn M., Lackner K., Ertl G.
The T1 relaxation times of the phosphorus metabolites in human heart muscle measurable by 31P-MR spectra were determined in 12 individuals using a 1.5 Tesla system. Several spectra were recorded consecutively with a pulse repetition time of 1.6 s to 24 s. The T1 times of creatine phosphate (CP), of γ-, α-, β-adenosintriphosphate (ATP), 2,3-diphosphoglycerate (2,3-DPG) together with anorganic phosphate) and phosphodiester (PDE) showed mean measurements of 6.1 ± 0.5, 5.4 ± 0.5, 5.0 ± 0.5, 5.8 ± 1.0, 7.6 ± 1.0, and 5.0 ± 1.0 s (M ± SE). The accuracy of the ISIS technique was tested with a special phantom. T1 times were also measured in standard solutions (20mM CP, 10mM ATP); CP was 8.7 ± 0.2 s and γ-ATP was 9.9 ± 0.7 s. Corrections for partially saturated 31P-MR spectra - at least for CP/ATP ratios - are relatively small.