Power Optimization of In-vivo Chemical Exchange Saturation Transfer (CEST) contrast for pH weighted Imaging
Zhou J, Huang J, van Zijl P, Sun P
Johns Hopkins University, F.M.Kirby Center
CEST imaging provides a unique contrast, reflecting properties of sometimes unobservable labile protons of metabolites and mobile proteins. Using solution phantoms, the optimal irradiation power has been derived. However, CEST is complicated in-vivo due to concomitant conventional MT. Here, we hypothesize that at weak and intermediate power, the endogenous CEST process can be modeled with an empirical equation developed for describing simultaneous proton transfer and spillover effects. The model fits well and could be applied to achieve great contrast improvement of pH-weighted imaging. Furthermore, this approach provides a strategy of reduction of energy deposit and duration for in-vivo CEST imaging.