Immersion medium independent microwave breast imaging

We present a method that shows that the finite element contrast source inversion (FEM-CSI) technique can be made independent of the utilized physical immersion medium by introducing a general numerical background permittivity. Two-dimensional and three-dimensional microwave breast reconstruction results are shown for data collected in various immersion media and inverted using a strategically chosen numerical background. Results show higher quality images for inversions that incorporate numerical backgrounds that reduce the position dependent contrast variable and utilize data that is collected using a physical background that provides the most diversity.