Figure 1.

Illustration of the process used to prepare the images for segmenting the glandular tissue. From the coronal slice (a), the voxel intensity in the background (air) is sampled and fitted to a Gaussian to obtain an optimal threshold. The breast is segmented from the background and a rectangular region that just includes the breast (b) is generated. The breast (b) is converted to polar coordinates (c) and a first order derivative filter is applied along columns to determine the skin layer (d). The skin layer (d) is subtracted from (c) to provide the breast tissue excluding skin in polar coordinates (e), which is then transformed to Cartesian coordinates (f).