EFFECTS OF DIELECTRIC HETEROGENEITY IN THE PERFORMANCE OF BREAST TUMOUR CLASSIFIERS

Breast cancer detection using Ultra Wideband Radar has been thoroughly investigated over the last decade. This breast imaging modality is based on the dielectric properties of normal and cancerous breast tissue at microwave frequencies. However, the dielectric properties of benign and malignant tumours are very similar, so tumour classiflcation based on dielectric properties alone is not feasible. Therefore, classiflcation methods based on the Radar Target Signature of tumours need to be further developed to classify tumours as either benign or malignant. Several studies have addressed the issue of tumour classiflcation based on the size, shape and surface texture of the tumour. In general, these studies examined the performance of classiflcation algorithms in primarily dielectrically homogeneous breast models. These relatively simplistic models do not provide a realistic test platform for the evaluation of tumour classiflcation algorithms. This paper examines the classiflcation of tumours under realistic dielectrically heterogeneous conditions. Four difierent heterogeneous scenarios are considered, with varying levels of heterogeneity and complexity. In this paper, the performance and robustness of tumour classiflcation algorithms under these realistic conditions are examined and discussed.