Magnetic induction tomography (MIT) is a new non-contacting technique for visualization of the electrical impedance distribution inside inhomogeneous media. A measuring system for MIT has been developed. An oscillating magnetic field is applied in the system as a sounding agent. The system is designed mainly for biomedical applications. Experiments demonstrate that with proper selection of measurement conditions it is possible to use the phase shifts between inductor and detector signals for image reconstruction by filtered backprojection along magnetic lines. Measurements with saline filled phantoms having various spatial distributions of conductivity were carried out and images were reconstructed. The experiments have demonstrated the applicability of MIT for medical imaging and diagnostics.

A medical device which allows imaging of the distribution of conductivity in 3D in regions below the skin surface has been developed and tested. Its purpose is to enable early detection and preliminary diagnosis of breast tumours. Design of the measuring system and software are described. Results of clinical evaluation of the system are presented. EIT images of healthy and cancerous breasts are presented and discussed. The system is able to visualize various states of the breast and it may be possible to apply it to breast cancer detection.

Results of development and testing of the new medical imaging system are described. The system uses a planar array consisting of 256 electrodes and enables obtaining images of the three-dimensional conductivity distribution in regions below the skin's surface up to several centimeters deep. The developed measuring system and image reconstruction algorithm can be used for breast tissue imaging and diagnostics, in particular for malignant tumor detection. Examples of tomographic images obtained in vivo during clinical tests are presented. The mammary gland, being an organ-target, alters at the background with such physiological events as menstrual cycle, pregnancy, lactation, and postmenopause. The objectives of this paper include estimation of the possibilities of electrical impedance mammography for investigation of mammary glands' state among women with different hormonal status. We found that electrical impedance mammograms from different groups had clear visual distinctions and statistically significant differences in mammary glands' conductivity. Our data on conductivity distribution in the mammary gland during different physiological periods will allow us to use it as normal values in the future, to continue this research on mammary glands with different pathology.

The method enabling one to obtain tomographic images of an electrically conductive or dielectric object by the excitation of the variable magnetic field inside it and by measuring the resulting field around the object is described. The main equations and theoretical estimations are given. It is shown that phasesensitive measurements should be used in magnetic induction tomography. The measuring system providing the data set necessary for the image reconstruction is discussed. Under the conditions of the measurements discussed in this paper, image reconstruction is possible with the use of a simple method of convolution and back‐projection along magnetic lines. Computer simulation demonstrates the visualization of the conductivity distribution by the method of magnetic induction tomography with phase measurements.

The technique of contactless imaging of resistivity distribution inside conductive objects, which can be applied in medical diagnostics, has been suggested and analyzed. The method exploits the interaction of a high-frequency electric field with a conductive medium. Unlike electrical impedance tomography, no electric current is injected into the medium from outside. The interaction is accompanied with excitation of high-frequency currents and redistribution of free charges inside the medium leading to strong and irregular perturbation of the field's magnitude outside and inside the object. Along with this the considered interaction also leads to small and regular phase shifts of the field in the area surrounding the object. Measuring these phase shifts using a set of electrodes placed around the object enables us to reconstruct the internal structure of the medium. The basics of this technique, which we name electric field tomography (EFT), are described, simple analytical estimations are made and requirements for measuring equipment are formulated. The realizability of the technique is verified by numerical simulations based on the finite elements method. Results of simulation have confirmed initial estimations and show that in the case of EFT even a comparatively simple filtered backprojection algorithm can be used for reconstructing the static resistivity distribution in biological tissues.