Highly Sensitive MRI Chemical Exchange Saturation Transfer Agents Using Liposomes

Contrasting views: Entrapment of a paramagnetic shift reagent for water protons inside liposomes dramatically improves the sensitivity of chemical exchange saturation transfer agents. The chemical shift of the water entrapped within the liposomes, relative to bulk water, depends upon the nature and concentration of the shift reagent as well as on the permeability of the liposome membrane (see picture; SR=shift reagent, Ln=lanthanide ion).