How is altered relationship between left and right hilum helpful in diagnostic interpretation?

• It gives clues to loss of lobar lung volumes
  • Left hilum will be pulled up with LUL atelectasis
  • Left hilum will be pulled down with LLL atelectasis
  • Right hilum will be pulled up with RUL atelectasis
  • Right hilum will be pulled down with RLL atelectasis
  • Hilar position does not change with RML atelectasis because of small volume of RML
• Displaced by mass