During a Phase I SBIR feasibility study, Quantex successfully demonstrated the feasibility of fabricating high resolution X-ray storage screens using its patented SrS:Ce,Sm storage phosphor. In the present Phase II continuation proposal, the aim is to fully optimize the performance of the SrS:Ce,Sm storage phosphor screens and to assemble a prototype digital read out and display system suitable for diagnostic mammography. Successful completion of this effort is expected to result in a cost effective diagnostic imaging system which is superior in performance relative to both screen/film systems and existing commercial X-ray storage phosphor screens and read out systems.