A Comparison of Tungsten and Molybdenum as Target Material for Mammographic X-Ray Tubes

Abstract

Controlled measurements of contrast at different densities were made using both tungsten and molybdenum targets. Exposures were made from 20 to 35 kVp in 5 kVp increments. The important densities of the breast were simulated by a Lucite and water step-wedge phantom and a calcium well phantom. No substantial difference in contrast was seen between molybdenum and tungsten in the soft-tissue density. At fat density, tungsten showed slightly better contrast at low kilovoltage (20 kVp), but molybdenum showed progressively greater contrast as the kVp increased. At calcium density, molybdenum showed greater contrast at all kVp levels.