Concentric ring sign

The concentric ring sign is a pathognomonic sign for a subacute haematoma on MRI.

A subacute haematoma may show 3 characteristic layers of  signal intensity:

  • a thin peripheral rim of low signal intensity on all pulse sequences corresponding to haemosiderin.
  • an inner peripheral high-signal intensity zone on T1-weighted imaging due to methaemoglobin.  
  • the central component of the haematoma has variable signal intensity based on the amounts of seroma, deoxyhaemoglobin, and methaemoglobin present.

This appearance of  the periphery of  a fluid  collection on T1-weighted imaging, known as the  concentric ring sign, which is pathognomonic for a subacute haematoma.

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Article Information

rID: 21490
System: Vascular
Section: Signs
Tags: refs, cases, sign
Synonyms or Alternate Spellings:
  • Target sign of haematoma on MRI
  • Concentric ring sign on MRI

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