Qualitative Techniques for Generating Spatial Prior Information for Biomedical Microwave Imaging

The use of quantitative microwave imaging for biomedical applications represents one of its most relevant application areas due to the specificity of the complex-valued permittivity with regard to differentiating normal and diseased anatomical tissues. The success of such quantitative methods relies on improving their reconstruction accuracy and resolution. In the following we propose the use of two qualitative imaging methods, the linear sampling and the orthogonality sampling methods, to generate spatial priors that are used as a numerical inhomogeneous background medium within the (quantitative) contrast source inversion scheme. Both qualitative imaging methods are able to create morphological maps, in almost real-time, from the same microwave scatteredfield data. The resulting quantitative reconstructions show improvements in both accuracy and resolution, compared to blind reconstruction, and thus the combined technique represents a significant contribution towards the design of simpler and low-cost imaging systems.