Differential microwave imaging of the stroke-affected brain via diffraction tomography

Abstract

In this study, we present the application of one of the traditional imaging method — Diffraction tomographyin monitoring of hemorrhagic brain strokes in order to evaluate the patient's condition. A realistic Zubal head phantom is used as the model and it is illuminated by 36 line sources in different scenarios to investigate the feasibility of method. The diffraction tomography based imaging methods can be confidently used only for weak scatterers. Differential data, which is obtained by measuring scattering fields in different time steps, can be treated as a weak scatterer. In addition, we have used a lossless matching medium with dielectric permittivity of 40, which not only enhances the penetration of microwaves to the brain, but also makes the measurements in far field more reliable. Reconstructed profile is extracted from differential data by solving a linear matrix system with least square method. Numerical results demonstrate that diffraction tomography can be an alternative to the previous methods with its simplicity and fast response time.