Learning Radiology xray montage

Scaphoid Cortical Ring Sign
Signet Ring Sign

General Considerations

  • The scaphoid cortical ring sign is produced by the foreshortened appearance of the distal pole of the scaphoid rotated on its axis by scapholunate dissociation, one of the manifestations of carpal instability syndromes
  • It may, however, be present normally and should be evaluated in light of clinical findings
  • Normally, the distance between the scaphoid and the lunate is < 3 mm in the frontal view
  • With scapholunate dissociation, this distance increase ( > 3 mm)
  • Ulnar deviation will cause an increase in the scapholunate gap
  • Radial deviation will close the gap 

Radiology Loves Its Ring Signs
Here are 10 More

Ring sign Ultrasound sign of peripheral nerve tumors
Ring sign CT sign of epiploic appendagitis
Ring sign Urographic sign of renal papillary necrosis
FLAIR Ring Sign MRI Marker of Dysembryoplastic Neuroepithelial Tumors
Incomplete/Open Ring Sign MRI sign of demyelinating disease
Tubal Ring Sign US sign of a tubal ectopic pregnancy
Choledochal Ring Sign CT sign of acute biliary pancreatitis
Signet Ring Sign CT sign of bronchiectasis
Ring Around the Artery Sign CT sign of pneumomediastinum
Fat Ring Sign CT sign may be seen with mesenteric panniculitis.

Scaphoid Cortical Ring Sign.
When there is rotation of the scaphoid as can occur with scapholunate dissociation (widening of distance between scaphoid and lunate to greater than 3 mm), (yellow arrow), a ring-shaped density can appear as a sign of foreshortening (white arrow).
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