“Jail bar” sign of vertebral hemangioma

Case contribution: Dr Radhiana Hassan


  • A 49-year-old female, underlying perforated sigmoid colon cancer.
  • CT scan done for staging.
  • Incidental finding of vertebral lesion

CT scan findings:

  • An ill-defined lytic changes seen at T10 vertebrae
  • There are striated vertical densities within it (yellow arrows)
  • On axial images the vertical densities are seen as rounded foci giving rise to ‘polka dot’ sign
  • No cortical break. No surrounding soft tissue mass

Diagnosis: Vertebral hemangioma (jail bar and polka dot signs)


  • The jail bar sign refers to the vertically striated appearance seen in vertebrae due to thickening of the bony trabeculae.
  • It is named as the appearance mimics the appearance of prison jail bars.
  • This appearance is strongly associated with vertebral hemangiomas.
  • It is also known as ‘colduroy cloth’ sign.
  • Axial CT will show a ‘polka-dot’ sign due to the thickened vertebral trabeculae. On CT the dots are white on a black fatty background.
  • On MRI they are black dots on a white background (on non-fat-suppressed T1 or T2-weighted images).
  • ‘Polka dot’ sign is also known as ‘salt and pepper’ sign for obvious reasons.
Author: radhianahassan