Hair on end sign (mnemonic)

Last revised by Matt Skalski on 10 Feb 2024

The hair on end sign refers to a radiographic appearance of the diploic space of the skull vault which results from a thickening of trabeculae as the diploic space expands. These trabeculae are perpendicular in orientation, interspersed by radiolucent marrow hyperplasia along with skull vault.

It is classically described with plain skull radiographs although can also be appreciated on CT or MRI 3. Causes include:

A useful mnemonic to remember the various causes of this sign is:

  • HI NEST 4

Mnemonic

ADVERTISEMENT: Supporters see fewer/no ads

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.