Ultrasound modulated electrical impedance tomography (UMEIT) is a novel hybrid imaging technique, which utilizes coupling between electric and acoustic modalities. Based on the forward solver along different current directions, an instrumental electrode configuration is proposed for 3D UMEIT. The proposed electrode configuration can produce a similar longitudinal current, making the power density distribution on the x-y plane approximately consistent with the corresponding conductivity distribution. Then, this satisfying power density is adopted to reconstruct a higher-resolution conductivity distribution. Therefore, the proposed electrode configuration contributes to improving the image reconstruction quality of UMEIT. Also, to clearly demonstrate its meaning in theory, the forward solver results are analyzed from an electrical point of view. In addition, the nonlinear partial differential equation (PDE) relating the power density to the measured data is derived again with a more reasonable expression. Finally, simulation with realistic geometry model of human breast is done and feasibility verifying experiment is made. Both simulation and experimental results validate the feasibility of the proposed electrode configuration.
Keywords: Electrical impedance tomography; Electrode configuration; Image reconstruction; Inverse probelm; Ultrasound modulated electrical impedance tomography.