This position raises the level of thoracic viscera, but this effect would be counteracted by the fact that all the scans were taken in full inspiration
. This takes the heart along with the great vessels and the tracheal bifurcation at a lower level than described in cadavers; thus, the levels described in anatomy books and levels seen in clinical practice in living subjects are different.
The total amount of air that one can exhale after full inspiration
Axial images are obtained at full inspiration
to maximize the contrast between areas of diseased and normal lung tissues. To differentiate gravity-related changes from pathological findings, CT imaging should be performed with the patient in both supine and prone positions.