Prefiltered Beamforming for Early-Stage Breast Cancer Detection

Ultrawideband radar imaging has been extensively investigated as a potential alternative to X-ray mammography and has shown promising results in the detection of small tumors within dielectrically homogeneous breast tissue. A range of confocal microwave imaging algorithms has been reported in the literature, showing good tumor detection capabilities, but most of these algorithms suffer significant deterioration in performance with increased amounts of fibro-glandular tissue in the breast. This letter proposes an improved beamformer based on a prefiltering approach to compensate for dispersion and phase effects in a dielectrically heterogeneous breast. The use of prefiltering is shown to improve on conventional beamformer performance and enables detection of multiple scatterers in dense breast tissue. The proposed improved beamformer is tested on 3-D anatomically and dielectrically accurate finite-difference time-domain (FDTD) breast models and the corresponding performance of the beamformer is evaluated across a range of appropriate metrics.