Two- and three-dimensional simulations of ultrasonic propagation through human breast tissue

Simulations of spherical-wave ultrasonic pulse propagation through human breast tissue are presented. Breast tissue models were created by processing of volumetric photographic data from the Visible Woman project. Tissue types were empirically mapped to hue, saturation, and value parameters of the photographic data; acoustic parameters of tissue were then mapped using empirical linear relationships between mass density, sound speed, and ultrasonic absorption. Computations of ultrasonic propagation were performed in two and three dimensions using a k-space method incorporating tissue-dependent absorption and absorbing boundary layers. The results show wavefront distortion effects similar to measurements on breast tissue. Statistically, wavefront distortion is significantly more severe for the three-dimensional simulations than for the two-dimensional simulations.