SU‐FF‐I‐141: Measuring Breast Density with Dual Energy Mammography: A Phantom Study

Abstract

Purpose: To investigate the feasibility of measuring breast density in phantoms with dual energy mammography. Method and Materials: Glandular and adipose equivalent phantoms of uniform thickness were used for dual energy basis decomposition calibration. The dual energy mammography system used a tungsten anode x‐ray tube with a 50 μm rhodium beam filter for low energy images and a 300 μm copper beam filter for high energy images. Three different phantom studies were used to evaluate the technique. The first study consisted of phantoms with thicknesses of 25–85 mm in 5 mm steps with a mean density of 28%. The second study consisted of step phantoms designed to more closely mimic the shape of a female breast with maximal thicknesses of 30–70 mm at a fixed density of 50%. The third study consisted of 40 mm thick phantoms of different sizes (62.5, 125, 250 cm2) at a fixed density of 50% to assess the effect of breast size on density measurement. Results: The RMS errors in breast density measurements were 0.4% for the uniform phantoms, 3.3% for the step phantoms, and 4.7% for the phantoms of different sizes. Conclusion: The results of phantom studies indicate that dual energy mammography can be used to measure breast density with an RMS error of less than 5%. Dual energy mammography can potentially be implemented with minimal changes to the standard mammography exam.