Image reconstruction incorporated with the skull inhomogeneity for electrical impedance tomography.

The structural similarity of the head model affects the accuracy of forward solution to electrical impedance tomography (EIT). Generally, the four-concentric circle model (FCCM) is used as the head model, which ignores the inhomogeneous distribution of the conductivity of real skull. In order to decrease the errors caused by using FCCM, a more accurate head model named inhomogeneous skull model (ISM) has been proposed and a reconstruction algorithm incorporated with ISM has been developed for brain EIT. Simulation results have shown improvement in image quality and localization accuracy when using ISM. It is also suggested that the reconstructed image could be more sensitive to the location of bony sutures than to the variation of skull thickness. In conclusion, incorporating skull inhomogeneity into image reconstruction is an effective way to improve image quality and localization accuracy for brain EIT.