title: Trochlear calcification: a common entity.
abstract: OBJECTIVE
  This study aims to quantify the prevalence of trochlear calcification.
  
  
  METHODS
  A retrospective case review was performed on orbital CT scans ordered at Wills Eye Emergency room and Jefferson Hospital for Neuroscience for patients from June 2009 through September of 2009.
  
  
  RESULTS
  In our series, we examined 132 scans, 61% (81/132) men, 39% (51/132) women, ranging in age from 10-83. We found a 13% (17/132) prevalence of calcification of the trochlea, 53% (9/17) unilateral and 47% (8/17) bilateral. Forty-one percent (7/17) were female, 59% male (10/17). Age (19-83) was not a factor in the presence of trochlear calcification. The calcification either came straight off of the bone or was free-floating in the trochlea.
  
  
  CONCLUSIONS
  Our study establishes that calcification of the trochlea is common in the general population with a prevalence of 13%. Calcification of the trochlea should be considered in the differential diagnosis of hyperintense densities in the superomedial orbit, especially in cases of trauma where it can be confused with a foreign body.
authors.affiliation: Wills Eye Institute Oculoplastic Service and Thomas Jefferson University, Philadelphia, Pennsylvania 52242, USA. rachel-sobel@uiowa.edu
authors.forename: Rachel K
authors.initials: RK
authors.lastname: Sobel
authors.forename: Scott M
authors.initials: SM
authors.lastname: Goldstein
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002114:Calcinosis / Q000000981:diagnostic imaging / Q000453:epidemiology*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009915:Orbit / Q000000981:diagnostic imaging; D009916:Orbital Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology*; D015995:Prevalence; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult