title: Anatomy of the transarcuate approach to the petrous apex.
abstract: OBJECTIVE
  Determine the dimensions of the approach to the petrous apex through the crura of the superior semicircular canal (SSC).
  
  
  METHODS
  Measurements obtained from high-resolution computed tomography (HRCT) images.
  
  
  METHODS
  One hundred ninety-two HRCTs were screened and 58 temporal bones with pneumatized posterior petrous apex cell tracts in 39 patients were identified and reviewed. Measurements were obtained with the assistance of the standard PACS (picture archiving and communication system) software.
  
  
  RESULTS
  The mean anterior-posterior (AP) dimension of the intercrural space of the SSC was 4.88 +/- 0.49 mm. The mean superior-inferior (SI) dimension of this space was 4.90 +/- 0.62 mm. When air cells were present in the intercrural space, the dimensions of the approach increased to 5.27 +/- 0.50 mm for the AP dimension (P = 0.014) and 5.27 +/- 0.70 mm for the SI dimension (P = 0.056).
  
  
  CONCLUSIONS
  The subarcuate approach is a potential route for the drainage of petrous apex cholesterol granulomas with minimal risk to the SSC, as demonstrated on HRCT measurements.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of California Irvine, Orange, CA 92868, USA.
authors.forename: Alice
authors.initials: A
authors.lastname: Lee
authors.forename: Sanaz
authors.initials: S
authors.lastname: Hamidi
authors.forename: Hamid
authors.initials: H
authors.lastname: Djalilian
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010579:Petrous Bone / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery*; D011857:Radiographic Image Interpretation, Computer-Assisted; D012016:Reference Values; D012665:Semicircular Canals / Q000601:surgery*; D014057:Tomography, X-Ray Computed