Evaluation of mammographic screen-film systems.

Four screen-film systems were evaluated for their imaging properties in mammography, Modulation-transfer functions were measured at 40 kVp. Absolute screen-film sensitivities in mR and entrance exposures were measured with tungsten and molybdenum target tubes. Five radiologists viewed radiographs of a phantom containing microgranules of SiC ranging in diameter from 590 to 120 micrometer. The Rarex-B screen--composed of yttrium oxysulfide--performed best, allowing phantom radiographs at 185 mR with image quality sufficient to demonstrate microgranules greater than 330 micrometer in dimension.