Measuring Tissue PH Heterogeneity by 31P NMR Spectroscopy

Norbert W. Lutz¹, Yann LeFur¹, Patrick J. Cozzone¹

Pathological processes are likely to induce variations in tissue pH. Thus, reliable measurement of intra and extracellullar pH (pHi, pHe) should be very useful for the characterization of tissue metabolism. ³¹P NMR-based methods exist for pH_i (chemical shift, δ, of endogenous P_i), and for pH_e (δ of exogenous APP). However, the consequences of pH heterogeneity within a measured tissue volume have not been considered in these pH calculations. We suggest here three ³¹P NMR-based pH calculation methods that take into account the characteristics of the pH distribution under consideration.