title: [20 MHz ultrasound diagnosis in chronic canaliculitis].
abstract: BACKGROUND
  High frequency sonography is used with a medium frequency of 50 to 100 MHz for non-invasive examination of the anterior eye segment. 20-MHz probes are considered to be a cost-efficient alternative, with a lower resolution and a higher penetration depth. We examined the value of the 20-MHz probe in diagnosing chronic canaliculitis.
  
  
  METHODS
  A 50-year-old woman was evaluated for a chronic canaliculitis. A pathognomonic sign of the chronic canaliculitis was the detection of concrements by high-resolution ultrasound. Grains measuring 1-2 mm in diameter could be shown in an ecstatic canaliculus with 20-MHz sonography. The high-resolution sonography showed the extent of the ectasia of the canaliculus and was therefore useful in planing the operative strategy.
  
  
  CONCLUSIONS
  The spectrum of possibilities in diagnosing chronic canaliculitis is broadened with this diagnostic tool. Specially when characteristic symptoms are missing, the 20-MHz probe may be useful in diagnosing patients with chronic canaliculitis.
authors.affiliation: Klinik und Poliklinik für Augenheilkunde, Ernst-Moritz-Arndt Universität Greifswald. Tost@mail.uni-greifswald.de
authors.forename: F
authors.initials: F
authors.lastname: Tost
authors.forename: R
authors.initials: R
authors.lastname: Bruder
mesh_terms: D000196:Actinomycosis / Q000000981:diagnostic imaging* / Q000601:surgery; D002137:Calculi / Q000000981:diagnostic imaging* / Q000601:surgery; D002908:Chronic Disease; D003607:Dacryocystitis / Q000000981:diagnostic imaging* / Q000601:surgery; D003608:Dacryocystorhinostomy; D005260:Female; D006801:Humans; D007767:Lacrimal Duct Obstruction / Q000000981:diagnostic imaging*; D008875:Middle Aged; D009301:Nasolacrimal Duct / Q000000981:diagnostic imaging / Q000601:surgery; D013290:Streptococcal Infections / Q000000981:diagnostic imaging* / Q000601:surgery; D014463:Ultrasonography