Using the microwave imaging technique for mammographic imaging is an interesting application and a growing research field. Compared to X-ray mammography there is potentially a significant benefit in using microwaves in the diagnosis of breast cancer tumours due to the high contrast in the dielectric properties between tumour and surrounding tissue.In this paper a tomographic microwave imaging ex- periment using transient time domain field data for the reconstruction process. A 2D iterative gradient based al- gorithm based on the FDTD-method (Finite Difference Time Domain-method), is used for the image reconstruction. The reconstructions have been performed using air as the background medium. To simulate more tissue like conditions the antennas have also been immersed in water and different objects immersed in the water have been imaged. Two different antenna models in the computations have also been tested. The results are promising and encourages further research on this method

In this paper with present the experimental results of imaging a 12mm copper rod immersed in water with a relative permittivity of ε = 78 , σ = 0.2. A copper rod is a simpler object to analyze for these first series of investigations than a hip prostesis. One should note that it has a relative permeability μ = μ0. The prosteses is also manufactured using titanium and it posseses a similiar permeability to that of copper. The setup used is very similiar to that proposed for the detection of breast cancer tumors [1],[2].The metalic rod is immeresed in water and is surrounded by an array of transceivers. The multi static data matrix is recorded as a function of frequency on the boundary of the medium under test. The multi static data matrix is a square complex symmetrix matrix. The elements consist of the received relative amplitude and phase between each sensor element as a function of frequency. A vector network analyzer and a switching matrix is used as the transceiver module. The mulitstatic data matrix is fourier transformed to time domain in order to be used in the FDTD based algorithm. The imaging algorithm used is similiar but a modified version to that proposed by Tanaka, Takenaka, He[3] and Gustafsson,He [4].The results of these first attempts to image metalic object are very promising and one can potentially use the proposed setup in various fields of medical imaging.

Microwave Imaging is an interesting tool and a growing research field in a number of applications. Compared to X--ray mammography there is potentially a significant benefit in using microwaves in the diagnosis of breast cancer tumors due to the high contrast in the dielectric properties between tumor and surrounding tissue. This paper is based on the first series of experimental results of a 2D iterative gradient algorithm based on the FDTD method (Finite Difference Time Domain method), which can be applied to microwave breast cancer imaging and possibly hip prosthesis dislocation.