%0 Journal Article %A A D Elster %A S C Jackels %A N S Allen %A R C Marrache %T Dyke Award. Europium-DTPA: a gadolinium analogue traceable by fluorescence microscopy. %D 1989 %J American Journal of Neuroradiology %P 1137-1144 %V 10 %N 6 %X A lanthanide series chelate, europium(Eu)-DTPA, was synthesized to serve as a histochemical analogue for the widely used MR contrast agent gadolinium(Gd)-DTPA. Eu and Gd, being neighboring elements on the periodic table, share many fundamental properties, including ionic radius, valence, and chemical reactivity. Eu-DTPA, however, possesses one important physical property not shared by Gd-DTPA: luminescence under ultraviolet light. The feasibility of detecting Eu-DTPA in animal tissues under fluorescence microscopy was systematically evaluated and documented. Distinctive orange-red luminescence of Eu-DTPA could be observed in the kidneys, livers, dura, choroid, and pituitary glands of rats after intravascular injection. No luminescence was detected in areas of brain beyond an intact blood-brain barrier. When the brain was locally injured by an experimental laceration, however, leakage of Eu-DTPA was detected. Electron probe microanalysis confirmed the parallel presence or absence of simultaneously injected Eu-DTPA and Gd-DTPA in all tissues studied. Fluorescence microscopy with Eu-DTPA has thus been validated as a method for tracing the distribution of Gd-DTPA at the microscopic level. %U https://www.ajnr.org/content/ajnr/10/6/1137.full.pdf