31P-NMR spectroscopy of myopathies: clinical application of whole-body MR.

Patients with myopathies were examined by 31P-NMR spectroscopy using a whole body MR system operating at 1.5 T. Spectra from the femoral muscles were measured as a function of time during a post-exercise recovery period. A 4-min scanning time was used to obtain a good S/N ratio and enable us to evaluate the relative intensity and position of each absorption line. The results were expressed by PCr/Pi ratio and pH value and compared with values before exercise. Clear changes were observed in the recovery process after workload depending on the stage of disease. We were able to observe the in vivo dynamic energy metabolism of myopathies by whole-body MR.