Estimation of pH values and magnesium ion content in vivo using a chemical shift dictionary for 31P MRSI at UHF

31P MRSI enables non-invasive mapping of pH value and magnesium content in vivo, and is conventionally done by calibration equations, like the modified Henderson-Hasselbalch equation, relating 31P chemical shifts to physiological parameters. The reliability of this approach might be hampered when applied to diseased tissue, like cancer, where the chemical conditions are altered. Recently, we proposed a chemical shift dictionary for 31P MRSI to potentially enable a condition-independent estimation of pH value and magnesium content. In this study, the applicability of this approach to in vivo data is tested, and its potential for further research identified.