Scanned-slot projection digital mammography

A prototype high-resolution scanned-slot x-ray imaging system is being developed to provide a practical means for digital mammography. The system consists of a scintillating phosphor coupled to a second-generation light amplifier and CCD via a fiberoptic reformatter. The reformatter provides a map of the optical signal form a long narrow slot (1 x 200 mm) to the square format of the optical detector. A limiting resolution of 12.5 lp/mm has been achieved. The authors are currently investigating the effect of the phosphor and fiberoptics on both MTF and spatial-frequency-dependent DQE. Experimental and theoretical results are presented. Preliminary images are shown to demonstrate slot geometry reconstruction techniques