Phosphorus Spectroscopy of Calf Muscles before and after Exercise

Background: The aim of this study was to determine 31PMRS reference spectrum and intracellular pH of calf muscles in the dominant limb of healthy, young, male volunteers before and after intense physical effort. Material/Methods: Examinations were performed with a 1.5 T MR system. FID CSI (Free Induction Decay Chemical Shift Imaging) sequence was used with the following parameters: TR=4000 ms, FA=90°, NEX=2 and VOI (Volume Of Interest)=8×8×8 cm3 (512 cm3) involving in calf muscles. Raw data was preprocessed using SAGE (GE) software. Authors analyzed relative concentrations ratios of selected metabolites: PCr/ATP and PCr/Pi. Intracellular pH and relative concentrations ratios of each metabolite (Pi, PCr, a-ATP, b-ATP, g-ATP, ATP) were also calculated relative to the sum of concentrations of all metabolites. Results were compared with a t-test. Results: Based on statistical analysis of results significant differences (p<0.05) were demonstrated for some of the studied metabolites and for intracellular pH. Increase in PCr concentration in relation to the sum of concentrations of all metabolites and to ATP concentration was noted. However, b-ATP, a-ATP and ATP concentrations relative to the sum of concentrations of all metabolites become reduced. Decrease in pH after physical effort was demonstrated. There were no significan