Compounds having general structure (I) have been found to be useful as stabilizers in photothermographic elements. The photothermographic elements comprise a support bearing an imaging coating (specifically, a photosensitive, image-forming, photothermographic coating) comprising:(a) a photosensitive silver halide;(b) a non-photosensitive, reducible source of silver;(c) a reducing agent for the non-photosensitive, reducible source of silver;(d) a binder; and(e) a compound having general structure (I) ##STR1## wherein X is O or S; and Y is NH.sub.2, OH, or O.sup.- M.sup.+ wherein M.sup.+ is a metal atom.The photothermographic elements may be used in medical imaging films or as a photomask in a process where there is a subsequent exposure of an ultraviolet or short wavelength visible radiation-sensitive imageable medium.