title: Is MRI Equal to CT in the Evaluation of Thin and Dehiscent Superior Semicircular Canals?
abstract: OBJECTIVE
  Can magnetic resonance imaging (MRI) diagnose abnormally thin and dehiscent superior semicircular canals (SSCs) that traditionally rely on evaluation by computed tomography (CT) imaging?
  
  
  METHODS
  Retrospective clinical study.
  
  
  METHODS
  Tertiary referral center.
  
  
  METHODS
  Adults who underwent both MRI and CT of the temporal bones over the past 3 years.
  
  
  METHODS
  CT and MR images of SSCs were separately reviewed, in a blinded fashion by three neuroradiologists at our institution. CT diagnosis of abnormally thin or dehiscent SSC was used as the "gold" standard.
  
  
  METHODS
  1) Dehiscent SSC. 2) Abnormally thin SSC. 3) Normal SSC.
  
  
  RESULTS
  One hundred temporal bones with evaluable superior semicircular canals from 51 patients were eligible for review on CT and MR imaging. There were 26 patients of thin SSC and 17 patients of SSC dehiscence on CT imaging, of which 13 and 15 respectively were also found on MRI. There were nine false-positive dehiscent SSC patients and four thin SSC patients observed on MR imaging while not observed on CT. For thin SSCs, MRI sensitivity was 61.9% and specificity of 94.3% with a positive predictive value of 81.3% and a negative predictive value of 86.2%. For dehiscent SSCs, sensitivity was 88.2% and specificity of 89.2% with a positive predictive value of 62.5% and a negative predictive value of 97.4%.
  
  
  CONCLUSIONS
  In this series, MRI in the axial and coronal plane had a high negative predicative value for thin SSC (86%) and dehiscent SSC (97%). However, MRI cannot conclusively diagnose thin or dehiscent SSCs.
authors.affiliation: *San Antonio Military Medical Center, San Antonio, Texas †Louisiana State University Health Science Center, New Orleans, Louisiana ‡Our Lady of the Lake Regional Medical Center, Baton Rouge, Louisiana, U.S.A.
authors.forename: Samuel A
authors.initials: SA
authors.lastname: Spear
authors.forename: Neal M
authors.initials: NM
authors.lastname: Jackson
authors.forename: Rahul
authors.initials: R
authors.lastname: Mehta
authors.forename: Christian E
authors.initials: CE
authors.lastname: Morel
authors.forename: Laura S
authors.initials: LS
authors.lastname: Miller
authors.forename: Dwayne
authors.initials: D
authors.lastname: Anderson
authors.forename: Moisés A
authors.initials: MA
authors.lastname: Arriaga
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007759:Labyrinth Diseases / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012665:Semicircular Canals / Q000473:pathology*; D012680:Sensitivity and Specificity; D013701:Temporal Bone / Q000473:pathology; D014057:Tomography, X-Ray Computed; D055815:Young Adult