One embodiment is a method of performing thoracic tomography on a human subject including performing multiple 4-wire impedance measurements on a region of interest to obtain measured impedance data; comparing the measured impedance data to simulated impedance data obtained from a plurality of models of the region of interest; for each of the models, determining a fit of the model based on a comparison between the simulated impedance data obtained from the model and the measured impedance data; and integrating individual resistivity estimates obtained from the models based on a fit of the model such that the individual resistivity estimate from a better fitting model is weighted more heavily in a final resistivity estimate than an individual resistivity estimate from a worse fitting model.