title: Vascular anomalies, sutures and small canals of the temporal bone on axial CT.
abstract: OBJECTIVE
  Subtle bony structures, small canals and fine sutures cause sometimes problems in the analysis of CTs of the temporal bone. The aim of this study was: to analyze the visibility of subtle structures and to estimate the incidence of vascular anomalies.
  
  
  METHODS
  We retrospectively analyzed axial scans of 223 high-resolution CTs of the temporal bone obtained as single slice or spiral CT with 1mm slice thickness. All CTs had clinical indications. Two experienced radiologists studied CTs regarding the visibility of the fine sutures, fissures and small canals and the occurrence of vascular anomalies.
  
  
  RESULTS
  The following structures were seen commonly: sphenosquamosal suture (76%), arcuate artery canal (93%), vestibular aqueduct (89%), mastoid emissary vein (82%), singular canal (56%). Not so commonly were observed: tympanosquamosal suture (31%), mastoid canaliculus (28%), lateral sigmoid sinus (28%), petrotympanic fissure (24%), tympanomastoid suture (10%). Seldom we identified: the inferior tympanic canaliculus (6%), high jugular bulb (6%), anterior sigmoid sinus (5%), dehiscent internal carotid artery canal (2%), persistent petrosquamosal sinus (1%), dehiscent jugular bulb (1%). Persistent stapedial artery, aberrant internal carotid artery, dehiscent jugular bulb, high jugular bulb with diverticulum, anterior and dehiscent sigmoid sinus were detected in below 1% of the analyzed temporal bones. The frequency of asymmetry of the jugular foramen, which varied between 3% and 42%, depended on different criterions of size.
  
  
  CONCLUSIONS
  A profound knowledge of normal anatomy and anomalies of the temporal bone avoids misinterpretation as pathological lesions and iatrogenic bleedings.
authors.affiliation: Department of Diagnostic Radiology, University of Halle, E. Grube Str. 40, 06097 Halle, Germany. sabrina.koesling@medizin.uni-halle.de
authors.forename: Sabrina
authors.initials: S
authors.lastname: Koesling
authors.forename: Petra
authors.initials: P
authors.lastname: Kunkel
authors.forename: Thomas
authors.initials: T
authors.lastname: Schul
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001165:Arteriovenous Malformations / Q000000981:diagnostic imaging*; D002648:Child; D002675:Child, Preschool; D003392:Cranial Sinuses / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013701:Temporal Bone / Q000033:anatomy & histology / Q000098:blood supply* / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*