Potential of MREIT conductivity imaging to detect breast cancer: experimental and numerical simulation studies

The conductivity values of cancerous tissues in the breast are significantly higher than those of surrounding normal tissues. Breast imaging using MREIT (Magnetic Resonance Electrical Impedance Tomography) may provide a new noninvasive way of detecting breast cancer in its early stage. In breast MREIT, the conductivity image quality highly depends on the amount of injected currents assuming a certain signal-to-noise ratio (SNR) of an MRI scanner. The injected current should not produce any significant adverse effect especially on the nerve conduction system of the heart and still distinguish a small cancerous anomaly inside the breast. In this paper, we present results of experimental and numerical simulation studies of breast MREIT. From breast phantom experiments, we evaluated practical amounts of noise in measured magnetic flux density data. We built a realistic three-dimensional model of the human breast connected to a simplified model of the chest including the heart. We performed numerical simulations of various scenarios in breast MREIT including different amplitudes of injected currents and predicted SNRs of MR images related with imaging parameters. Simulation results are promising to show that we may detect a cancerous anomaly in the breast while restricting the maximal current density inside the heart below a level of nerve excitation.