4D Digital Breast Phantom for Contrast-Enhanced Imaging

Abstract

A fully simulated 4D digital breast phantom model is developed inthis work. The model is based on an anthropomorphic digital breast 3D phantom, which gives the user better control of the 4D phan- tom features when it comes to developing and optimizing contrast enhancement imaging techniques. The fourth dimension of the phan- tom features different time-varying enhancement patterns for differ- ent materials including fibro glandular tissue and mass tissue. Phys- iological parameters that capture the key characteristics of different types of masses, for example, wash-in and wash-=out rates indicating metabolism level, are employed in the model to simulate certain fun- damental features for categorizing mass types. A two-compartment model, a well-known model in the field of Pharmacokinetics, is used to depict the diffusion process of the contrast agent. Two methods are proposed to allow the simulation of the necrotic core with varying shapes. To explore the benefit of the 4D phantom, digital mammograms are simulated and studied by the Monte Carlo method. To perform the simulation, the contrast agent blood tissue mixture’s cross-section pa- rameters are generated by linear interpolation between the parameters of blood, contrast agent, and tissue (mass or fibro glandular tissue). With the contrast agent in the tissue, higher contrast is achieved be- tween fibro glandular tissue and mass tissue. The contrast is then further enhanced by the log scale subtraction between high and low- energy mammograms.