title: High resolution ultrasound in posterior interosseous nerve syndrome.
abstract: BACKGROUND
  Posterior interosseous nerve (PIN) syndrome is a rare compression neuropathy of the PIN in the region of the supinator muscle, most common by the arcade of Frohse. We aimed to specify ultrasonographic findings in patients with PIN syndrome in comparison to healthy volunteers.
  
  
  METHODS
  Ultrasound images and clinical data of 13 patients with PIN syndrome confirmed by neurological examination and electrophysiological testing were evaluated retrospectively. Anteroposterior nerve diameters measured at the arcade of Frohse were compared with those of 20 healthy volunteers. The echotexture and the presence of a caliber change of the PIN were additionally assessed.
  
  
  RESULTS
  Enlargement of the PIN was seen in all patients with PIN syndrome, but not in volunteers (statistically significant difference in mean diameter P < 0.05). Furthermore, edema and caliber change of the PIN were present in all patients.
  
  
  CONCLUSIONS
  High-resolution ultrasound allows for differentiation between patients with PIN syndrome and healthy volunteers.
authors.affiliation: Innsbruck Medical University, Department of Radiology, Anichstrasse 35, 6020, Innsbruck, Austria.
authors.forename: Tanja
authors.initials: T
authors.lastname: Djurdjevic
authors.forename: Alexander
authors.initials: A
authors.lastname: Loizides
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Löscher
authors.forename: Hannes
authors.initials: H
authors.lastname: Gruber
authors.forename: Michaela
authors.initials: M
authors.lastname: Plaikner
authors.forename: Siegfried
authors.initials: S
authors.lastname: Peer
mesh_terms: D016022:Case-Control Studies; D003937:Diagnosis, Differential; D004487:Edema / Q000175:diagnosis / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000175:diagnosis / Q000000981:diagnostic imaging*; D011826:Radial Nerve / Q000000981:diagnostic imaging; D020425:Radial Neuropathy / Q000175:diagnosis / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D014463:Ultrasonography / Q000379:methods*
keywords: arcade of Frohse; compression neuropathy; high-resolution ultrasound; posterior interosseous nerve; radial nerve; supinator muscle