Exploring the enhancement of the imaging properties of a microwave radiometry system for possible functional imaging using a realistic human head model

During the past four years, a novel Microwave Radiometry Imaging System (MiRaIS) has been developed and experimentally tested for brain activation imaging via contactless measurements. Through analytical theoretical and experimental analysis, the system seems to be able to detect any change of the product of temperature (T) and conductivity (σ), that is change of the product T*σ. However, in order to be able to study any specific brain area of interest using the proposed system, its focusing properties need to be improved. The present work investigates the use of dielectric materials as filling material inside the whole ellipsoid geometry or as matching layer around the head. Aim of both ideas is to improve the matching conditions on the skin-air interface. The results from the simulations verified the validity of this approach and also that focusing points appear to be sensitive to the spatial movement of the head. For the simulations, a commercial FDTD tool is used, along with an anatomically correct human head model developed from MRI scans. SAR distributions are also calculated inside the head revealing the potential implementation of hyperthermia treatment with the proposed system.