Temperature Mapping Using Combined T2 and Diffusion Weighted MRI of Encapsulated Phase Change Materials

A spin-spin T-2 relaxation correlation with temperature is developed for core-shell particles containing eicosane. These phase change materials (PCMs) provide a novel NMR temperature sensor for studying spatial variations in packed bed heat transfer. Thermocouples are used to map the temperature field within the RF coil over a range of temperature. MRI T-2 maps at fixed temperatures are then used to develop a direct correlation between the NMR relaxation and temperature, allowing temperature maps to be measured. It is shown that using the combined effects of T-2 relaxation and diffusion weighting of the read imaging gradients, a robust temperature correlation can be developed.