Partial Absence Pericardium - CT

In the absence of left pericardium, one can see the "Snoopy dog" appearance (better appreciated on radiograph) with left cardiac shift. The apex is snoopy's nose. Air interposed between aortic arch and main pulmonary artery with prominent left atrial appendage forms Snoopy's ear. Air is also interposed between left hemidiaphragm and inferior heart border.