On the matching medium for microwave stroke diagnosis**This work was supported in part by the University of Queensland under the University of Queensland Postdoctoral Research Fellowship Scheme, Chalmers University of Technology under the Karl G Eliasson Supplementary Fund, and Swedish Research Council under Grant number 2010-7262-78830-59.

Abstract

The choice of matching medium can directly affect the amount of power transmitted into and through human bodies, which impacts on the quality of the reconstructed images in microwave-based medical imaging, and thus the diagnosis accuracies. In this paper, the amount of the transmitted and reflected power of multi-layer planar healthy and hemorrhagic stroke brain models under different choices of matching medium are determined. These multi-layer planar brain tissue models are made up of at least 17 tissue layers with realistic dielectric properties. A layer of blood with different thickness is introduced to model the case of hemorrhagic stroke. Our results show that matching medium with low relative permittivity provides better intrinsic contrast between healthy brain and hemorrhagic brain. Analysis on how the reflection coefficient and transmittance vary under different matching medium are included to provide better insights to the findings.