Excitation Patterns in 3D Electrical Impedance Tomography for Breast Imaging

Electrical impedance tomography (EIT) has been used for breast cancer detection as a complementary technique to mammography and magnetic resonance imaging (MRI). Three-dimensional (3D) EIT is being investigated with the improvement of instrumentation and numerical modeling. In this paper, a hemisphere breast model and a three-layer electrode distribution for 3D EIT are used. The excitation patterns in 3D EIT based on one current source, including the traditional neighboring method and opposite method are discussed and then a s-shaped method is proposed. Numerical experiments are carried out to analyze the singularity of the Jacobian matrix, dynamic range of the measured voltage and image quality, which are obtained by using different excitation methods. The results show that the proposed s-shaped method can provide low dynamic range of the measured voltage and good visual shape reconstruction for breast imaging.