Dynamic phosphorus MR spectroscopy of the skeletal muscles during work in an MR-compatible ergometer.

A) The recorded signal is sensitive to phosphorus bound in metabolites, which are recorded over 12 minutes. The illustration shows that the most significant amplitude for phosphocreatine (PCr) decreases as the muscles perform work.

B) Plot of the change in PCr from rest (2 min) to work (5 min) and then rest again (2 min). It is also seen that PCr decreases during work and that the level of inorganic phosphate (Pi) increases.

C) If the spectra are summed over time, the different metabolites bound to phosphorus are clearly seen. PCr, phosphocreatine. Pi, inorganic phosphor. ATP alfa (α), beta (β), and gamma (γ).