Microwave Tomographic Imaging of Anatomically Realistic Numerical Phantoms with Debye Dispersion for Breast Cancer Detection Using a Regularized Inverse Scattering Technique in the Time Domain

In recent years, three similar versions of time-domain inverse scattering (TDIS) algorithms have been proposed for the successful estimation of the dispersive dielectric properties of several single-pole Debye media. For practical applications in common biomedical engineering, an improved TDIS algorithm is explicitly derived to provide a more versatile algorithm for the microwave tomographic imaging of biological tissues. Its three improvements are as follows. The number of poles for Debye models is extended from one to a positive integer W. The second improvement is the extension of unknowns from three to 2W+2 for each discretized cell. The third improvement is the adoption of the first-order Tikhonov regularization scheme. Based on the four classes of 2-dimensional anatomically realistic numerical phantoms with two-pole Debye dispersion from the University of Wisconsin Computational Electromagnetics Laboratory (UWCEM) database, the performance of the developed algorithm for the detection of a 3-mm-diameter tumor implanted in the four types of breast models was investigated for three scenarios. The obtained results preliminarily indicate that the modified technique is feasible and promising for the quantitative reconstruction of sparse breast tissues.