High speed positive-working photothermographic radiographic film

摘要

The present invention is directed to a method of forming a positive image in a photothermographic assembly comprising a photothermographic material and an intensifying means for converting ionizing radiation, wherein the assembly has been imagewise exposed to ionizing radiation to form a latent image in the photothermographic material. The photothermographic material has at least one imaging layer comprising a potentially negative-working emulsion, wherein thermal development of unexposed silver salts in exposed areas relative to unexposed areas is inhibiting when thermally developing the imagewise exposed assembly, thereby producing a positive image. The present invention is also directed to a photothermographic assembly that can be used in the present process in which a positive image characterized by high speed and discrimination is formed when exposed and thermally heated above 150° C.