Electrical Impedance Tomography is a relatively new technique whereby objects or phantoms can be imaged through injecting the containing medium with electrical currents along its periphery. EIT, in its various forms, has been applied to several areas in medical diagnosis and monitoring, including the measurements of breast tissues impedance. Studies have shown that cancerous tissues have electrical properties that are significantly different from their normal surroundings. X-ray mammography has been set as the primary method of breast cancer screening. However, EIT currently still falls within a category of techniques which are used as adjunct methods to X-ray mammography, in this category are Ultrasound and MRI. These techniques are used as follow-up on the results of mammography. the problem of estimating the inner conductivities from surface measurements is an ill-conditioned problem in which some regularization strategies have to take place in order to obtain a stable and accurate solution by incorporating some prior information into the solution. the purpose of this paper is to demonstrate the application of EIT on a patient-specific model for the single- and multiple-electrodes models and discuss the pros and cons of adding dimensionality to the model with respect to the image reconstruction process. This comparison will be based on the RMSE (Root mean square error) and Pearson's correlation criteria which were not used previously in this respect.