Fig. 4.

Distributions of functional, optical, and acoustic properties: (a) oxygen saturation $s$, (b) blood volume fraction $f_b$, (c) optical absorption coefficients ${\mu }_a$, and (d) optical scattering coefficients ${\mu }_s$ at a wavelength of 800 nm, (e) sound speed $c$, and (f) density $\rho$ of type A to D breasts (top to bottom). The type A and B breasts (top two rows) have two lesions inserted, one with a necrotic core and PA region and the other without, whereas the type C and D breasts (bottom two rows) have four lesions of different sizes inserted, each smaller than 10 mm in diameter and composed solely of a VTC region. Insets of (a)–(c) show cross-sections, with the lesion location indicated with arrows. Paraview⁴⁰ was used for volume rendering, and color maps were adjusted for better visibility.