Radar-based time-domain head imaging using database of effective dielectric constant

In radar-based time-domain head imaging, a priori information on the effective dielectric constants from the antennas´ perspective with respect to different head pixels is needed to map the significant scatterrers inside the head. A microwave-based head imaging technique, which utilises a model for the effective dielectric constant as a function of the antenna´s position and imaged point inside the head, is presented. To build that model, a realistic MRI-derived numerical head surrounded by an array of wideband antennas is implemented in a full-wave electromagnetic solver. The time difference of arrival between transmission coefficients in free space and inside the head is calculated at different head pixels and used to evaluate the effective dielectric constant at those pixels. The model is validated on two different head phantoms and used to accurately detect different brain strokes.