A Study on Dual-Energy Subtraction in Digital Mammography

摘要

Experimental subtraction of phantom digital mammographic images obtained at 25 and 40 kVp Mo/Mo and Rh/Rh, normal and hardened beams, has been performed. Single energy attenuation measurements in human microcalcifications show a weaker absorption than expected from CaCO_3 composition. Signal-to-noise ratios in the subtracted images have been compared with numerical calculations following Lemacks formalism, and qualitative agreement is obtained. The expected increase in contrast when the high voltage beam is hardened is observed in the measurements.