Neonate chest

  • AP and transverse diameter equal, giving a cylindrical configuration
  • rotation assessed by comparing length of anterior ribs
  • normal cardiothoracic ratio up to 0.6
  • variable thymic size
  • thymic involution: prenatal or postnatal stress, hyaline membrane disease, corticosteroid treatment
  • known artefacts: hole in incubator top looks like pneumatocele. skin fold mimic pneumothorax