Two different prototype high resolution digital x-ray radiographic imaging systems employing planar array charge-coupled device detectors have been constructed. Both proto-type imaging units have an ultimate resolution capability of at least 10 line pairs/mm. Each system employs a standard 20 x 30 cm x-ray intensifying phosphor screen as the input receptor. One unit operates as a scanning system utilizing a specially manufactured planar array (244 x 380 elements) operating in a time delay and integration mode (TDI). The other system employs a static array (640 x 1024 15 micron square pixels) operating in "snapshot" read out mode. Our studies utilizing these devices with standard clinical radiation exposures have shown a significant improvement in the visualization of low contrast objects in radiographic phantoms and both units have an ultimate resolution capability of at least 10 line pairs/mm.