Incorporating a priori anatomical information into image reconstruction inelectrical impedance tomography

Image reconstruction in electrical impedance tomography using the sensitivi ty theorem is generally based on the assumption that the initial conductivi ty distribution of the body being imaged is uniform. The technique of image reconstruction using this method is described and reconstructed images are presented. Improvements in image quality and accuracy are demonstrated whe n accurate a priori 'anatomical' information, in the form of a model of the distribution of conductivity within the region to be imaged, is used to co nstruct the sensitivity matrix. In practice correct a priori information is not available, for example the conductivity values within the various anat omical regions will not be known. An iterative algorithm is presented which allows the conductivity parameters of the a priori model to be determined during reconstruction.