The goal of this study is to characterize the ability of the electrical impedance tomography system (hardware and software) to distinguish between lung pathologies by assessing the sensitivity and specificity as well as the overall agreement with the CT scan in terms of spatial resolution. The study will test, as well as refine, the mathematical algorithms needed to create meaningful outputs on adult patients receiving mechanical ventilation and who also have received or will be receiving a CT scan as part of their standard of care.