A high-resolution scanned-projection radiography system is proposed for digital mammographic applications. By using a wide, dynamic-range CCD detector, some of the current limitations encountered in conventional film-screen mammography can be avoided. One-dimensional, fanbeam geometry provides very good scattered xray redu ction . A time-delay- and-integrate (TD I) mode of CCD imaging with a 2,048 X 96 element CCD array provides the opportunity to image without the excessive power-loading of x-ray tubes that would be required with a 2,048 X 1 array. By utilizing TDI charge integration while the detector is scanned, each projection through stationary anatomy is averaged over 96 exposures, thereby providing a significant signal-to-quantum mottle improvement of approximately 10:1 when compared to a 2,048 X 1 detector at the equivalent tube loading.Developmental tasks to be performed include construction of a TDI-CCD x-ray detector in which the light output of an x-ray-intensifying screen is coupled by means of a lens to the CCD focal plane, measurement of x-ray sensitivity, assessment of noise characteristics and homogeneity of the x-ray detector construction of a moving-sample x-ray imaging system based on the TDI detector, and determination of the optimum x-ray spectrum for digital mammographic imaging tasks to evaluate its clinical potentialNational Cancer Institute (NCI)
