As a sensitive MRI method, Chemical Exchange Saturation Transfer (CEST) MRI based on
endogenous contrast has been increasingly utilized for molecular imaging of various metabolites.
Among these applications, the authors have described CEST MRI for molecular imaging of brain metabolites
in this review, including brain glutamate, the most abundant excitatory neurotransmitter;
creatine, a key molecular of bioenergetics; and myo-inositol, a biomarker of glial cells. Those metabolites
conventionally have been quantified with MR spectroscopy methods. Compared to MR spectroscopy,
CEST methods typically provide a few hundred to a few thousand fold enhancement in sensitivity, enabling twodimensional
imaging or mapping of metabolites at high resolution. In this review, the authors have also reviewed the preliminary
applications of these molecular imaging methods. Finally, the challenges related to CEST MRI for molecular imaging
in general are discussed.