Investigation of polyvinyl alcohol (PVAL) composite gels and the outcome of variation in breast phantom densities on image quality and dose in full-field digital mammography

Abstract

This study evaluates the possibility of using a blend of polyvinyl alcohol (PVAL) and graphite powder as phantom materials to stimulate an extremely dense breast tissue for mammography based on the Breast Imaging-Reporting and Data System (BIRADS). The linear (μ) and mass attenuation coefficients (μ/ρ), computed tomography (CT) number, and physical and relative electron densities of the fabricated PVAL materials were determined. Mammography images of the fabricated PVAL materials and standard RMI 156 mammography phantoms were acquired using full-field digital mammography (FFDM) system at 28 kVp. The effect of breast density on contrast (Cn), contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and mean glandular dose (MGD) were evaluated. The fabricated phantoms made from PVAL + 4% graphite powder (G4) showed good resemblance to extremely dense breast tissues (BIRADS D). Higher Cn, CNR, and SNR values were achieved with lower density breast equivalent phantoms. Density correlated positively with mean glandular dose (MGD) and the values of the MGD for the different categories of phantoms were within the acceptable limit of 3.0 mGy consistent with the ACR protocol.