Effect of mammographic breast density on high-frequency ultrasonic parameters used to evaluate surgical margins

Abstract

Breast density, the proportion of connective tissue versus fat tissue in the breast, is typically determined using mammography. Women with higher breast density are four to five times more likely to develop breast cancer than women with lower densities. A surgical study performed by Utah Valley University with the Huntsman Cancer Institute showed that high-frequency ultrasound (20–80 MHz), and the parameters peak density (number of spectral peaks and valleys from 20 to 80 MHz) and attenuation, are sensitive to breast tissue pathology. This study also showed that breast density had no effect on peak density across the entire breast density range while attenuation increased 2X from entirely fat to extremely dense. The present study’s objective was to determine the effect of breast density on these parameters using histology mimicking phantoms. Phantoms were created from distilled water, agarose powder, 10X TBE stock solution, and polyethylene microspheres and fibers to simulate breast tissue histology. Phantoms were produced with microspheres only, fibers only, and a combination of microspheres and fibers. Pitch-catch measurements were acquired using a high-frequency ultrasound system and glycerol as the coupling agent. The phantom results validate the surgical study, showing attenuation increasing with inclusion concentration but no significant change in peak density.