Tidal volume distribution will be assessed with the use of Electrical Impedance Tomography (EIT). Images will be acquired in the supine Position 5 minutes before anesthesia induction, 5 minutes after induction as well as 5 minutes completion of xenon wash-in. EIT measurements will be made for a period of one minute and functional EIT images of changes in tidal impedance will be generated. The Center of Ventilation Index and Global Inhomogeneity Index will be calculated for each time point.