Horizontal versus vertical, or lying down is better.
D000388:Air; D006801:Humans; D007231:Infant, Newborn; D009359:Neonatology / Q000379:methods*; D011187:Posture; D011860:Radiography, Abdominal; D013902:Radiography, Thoracic / Q000379:methods*; D013679:Technology, Radiologic