Synopsis

Phosphorus-31 MRS can deliver quantitative metabolic information directly as peak intensities (reflecting metabolite concentration) or indirectly, via metabolic models. ³¹P sensitivity is high enough to acquire time series of thermal spectra, even localised, that reveal fluxes and rate constants of high-energy metabolites. Large ³¹P signal changes upon exercise make skeletal muscle a particularly interesting target for metabolic studies using dynamic ³¹P MRS. Other organs, like heart, liver or brain, can be investigated with magnetisation transfer or static ³¹P methods. ³¹P MRS information content can be further enriched by interleaved or simultaneous acquisition of ¹H MRS or MRI data.