Simultaneous 1H MRS measurement of temperature and pH with a lanthanide complex
Caldwell M, Hyder F, Coman D, Trubel H, Rycyna R
In vivo measurements of brain temperature and pH distributions are scarce, mainly due to the lack of non-invasive methods. The proton resonances from the shifting reagent TmDOTP5- are strongly dependent on temperature and pH. Previous linear models used two resonances to determine temperature and pH. We propose a new non-linear model which exploits temperature and pH information that is stored in three of the resonances of TmDOTP5-. The variable temperature and pH interdependencies provide a redundant framework, not exploited previously, to allow more accurate calibrations for temperature (0.05 C) and pH (0.02) in vitro and in vivo.