Volumetric Breast Density Determination Based On X-Ray Phase-Shifts
X Wu1*, A Yan1, H Liu2, (1) Univ Alabama Birmingham, Birmingham, AL, (2) Univ Oklahoma, Norman, OKTH-A-217BCD-9 Thursday 8:00:00 AM - 9:55:00 AM Room: 217BCD
Purpose: High breast density is one of the biggest risk factors for breast cancer. Identifying patient having persistent high breast density is important for breast cancer screening and prevention. In this work we propose for the first time an x-ray phase-shift based method for measuring the volumetric breast density.
Methods: When x-ray traverses the breast, x-ray not only gets its intensity attenuated, but also gets its phase shifted. Studying the x-ray phase-shifts generated by the breast tissues, we derived a formula for determining the volumetric breast density from the breast phase map. We show that the volumetric breast density can be reconstructed by retrieving the breast phase map from just a single phase-sensitive projection of the breast. To validate this phase-shifts method for measuring the volumetric breast density, we performed computer simulations with an anthropomorphic digital breast phantom. In the simulation we simply set the ray path-lengths inside a breast to its compressed thickness as a practical approximation.
Results: Using this phase-shifts based method, we reconstructed the phantom's volumetric breast density that is differs from the true breast density of the phantom by only 0.22%, achieving a good accuracy for the breast density determination. With the existence of projection noise, the reconstructed volumetric breast density differs from the true breast density of the phantom by only 1.42% or less as long as the breast signal-noise ratios being larger than 34.
Conclusions: We proposed an x-ray phase-shift based method for measuring the volumetric breast density. The simulation results validated this novel method.