In vivo breast imaging with diffuse optical tomography based on higher-order diffusion equations.

We report on in vivo absorption and scattering imaging of a human breast cyst and implant, using a reconstruction algorithm based on our third-order diffusion equations. To validate these in vivo images, a series of phantom experiments were conducted, in which we used low-absorbing and low-scattering heterogeneities to mimic a breast cyst or implant. These heterogeneities or targets were composed of pure water or a mixture of water and very dilute Intralipid (0.05% and 0.1%). The phantom experiment confirmed the quantitative imaging capability of our improved algorithm for reconstructing heterogeneities where the conventional diffusion approximation is inadequate. Pilot clinical results from female volunteers indicate that enhanced diffuse optical tomography can quantitatively image findings such as breast cysts or implants in which the absorption and scattering coefficients are usually low.