Pressure Dependent Signal Enhancement in Hyper-CEST

Wolfgang Kilian¹, Lorenz Mitschang¹, Christian Freund², Andreas Schlundt²

The so called hyper-CEST method promises tremendous potential on molecule-specific MR imaging using hyperpolarized ¹²⁹Xe caged in functionalized cryptophane cages. Here we present a model which allows for an optimization of the hyper-CEST sensitivity in biosensor applications, by variation of the xenon concentration in the solution. To evaluate the model we have performed hyper-CEST measurements on samples with 5 μM and 0.5 μM biosensor concentrations and varied the dissolved xenon concentration. This comparison shows that 50 nM biosensor concentrations should be detectable within a volume of 1 ml with high sensitivity.