Electrical Impedance Mammography is tomographic non-local technology of imaging. It is based on cross-sectional data collection, back-projection method with horizontal and vertical weighing function and static image method. The analysis of information received using the abovementioned methods gave an opportunity to create diagnostics system in electrical impedance mammography. It includes the following diagnostic criteria: structural percentile limits and age-related electrical conductivity, statistics of excursions and early diagnostics of breast cancer, D-statistics and distorted mammographic scheme in cases of breast cancer, diagnostics table and evaluation of electrical impedance image.
- Structural percentile limits and breast structure. Structural percentile limits were defined as the result of study of distribution of mean electrical conductivity of breast using a blind method, without regards to age. Structural percentile limits allow to determine the structure of mammary gland and its density.
- Age-related percentile limits and age-related electrical conductivity. Data of more than 5 000 electrical impedance mammographic examinations received from healthy women aged between 20 and 80 were analyzed. Further, age-by-age analysis of electrical impedance mammograms was held using the method of percentile limits. Percentile limits of age-related electrical conductivity should be used for the formation of breast cancer risk groups.
- Statistics of excursion and early diagnostics of breast cancer. Electrical properties of a cancer tumour differ significantly from the electrical properties of the surrounding tissues, thus showing the so-called ‘excursions. This fact can be used for early diagnostics of breast cancer. In order to solve this task, areas with abnormally high values of electrical conductivity are detected, which are characteristic of oncologic processes.
- D-statistics and distorted mammographic scheme in cases of breast cancer. Cross-sectional method of data collection and method of back projection with horizontal and vertical weighing function imply the existence of reciprocal influence of the surrounding tissues and oncologic process. As the result of this process, mammographic scheme becomes distorted. Dx statistics allows to distinguish between a normal mammographic scheme and a distorted one, which is typical for breast cancer.
- Diagnostics table and evaluation of electrical impedance image. Mass lesion is a space-occupying lesion, which is determined on several scans. As a rule, the analysis of images includes assessment of the shape, contour, internal electrical structure of the lesion, changes in the surrounding tissues. EIM scoring scale allows to standardize the description of mass lesions during electrical impedance mammography and to use the survey algorithm developed by specialists from American College of Radiology.