Hilum overlay sign

The hilum overlay sign refers to the appearance of an abnormally dense hilum on frontal chest radiographs.

If a mass arises from the hilum, the normal pulmonary vessels (interlobar artery, upper lobe arteries, and left descending artery) 2 are in contact with the mass and their silhouette is obliterated. If the edges of the vessels are appreciated, this implies the mass is not in contact with the hilum and is, therefore, either anterior or posterior to it.

Most of these masses are found to be in the anterior mediastinum.

History and etymology

Dr Benjamin Felson (1913-1988) was an American radiologist who first described this sign 3.


Chest x-ray
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Article Information

rID: 15494
System: Chest
Section: Signs
Synonyms or Alternate Spellings:

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