Abstract
The aim in Electrical Impedance Tomography (EIT) is to exploit the difference in the passive electrical properties of tissues in order to generate a tomographic image. The advantage of such a technique over other imaging modalities is that it provides a non invasive and sensitive method of probing the body using non ionizing radiation. The relative low cost and its suitability to perform long term monitoring are also very desirable features. Furthermore, EIT identifies information not provides by other imaging techniques, namely the electrical properties of tissue. This may reveal important clinical indicators not provided by other tissue properties. Single frequency electrical impedance tomography offers many positive attributes which are now being exploited clinically, but there are also problems which have been identified. One of the most important problem is that only the changes in the real part of conductivity can be imaged and not those of the imaginary part of conductivity or of the absolute values. Multi-frequency electrical impedance tomography has been proposed to solve this problem by making impedance measurements over a range of frequency. In this work two methods concerning 2D Multi frequency electrical impedance tomography and 3D Multi-frequency image reconstruction have been developed. The new developed methods show improvements in image quality reconstruction in multi frequency impedance tomography. The full information confined in the complex tissue conductivity can be obtained using these methods. These methods were applied in some models and acceptable results and image improvement relative to the previous work were obtained.