title: Transverse sinus stenosis in adult patients with Chiari malformation type I.
abstract: OBJECTIVE
  Transverse sinus stenosis is an imaging finding very highly associated with elevated intracranial pressure (ICP). Patients with the Chiari I malformation may potentially have elevated ICP due to impairment of CSF flow at the foramen magnum. This study evaluated whether patients with Chiari I malformation have transverse sinus stenosis and other imaging findings indicative of elevated ICP.
  
  
  METHODS
  Thirty patients with Chiari I malformation treated surgically and 76 control subjects were identified retrospectively. All control subjects and all patients with Chiari I malformation (preoperatively) underwent standardized contrast-enhanced brain MRI including a contrast-enhanced 3D T1-weighted sequence from which curved reformats of the transverse sinuses were generated. Two different readers blinded to the diagnosis then independently evaluated these curved reformats for severity of transverse sinus stenosis. Orbital and skull-base findings previously described in association with elevated ICP were also evaluated. Frequency of MRI findings between the two groups was compared.
  
  
  RESULTS
  Patients with Chiari I malformation had significantly greater frequency of unilateral or bilateral transverse sinus stenosis than did control subjects (p < 0.001). There was complete interreader agreement on presence or absence of transverse sinus stenosis by patient (κ = 1.0 [95% CI, 0.89-1.0]). Logistic regression analysis controlling for age, sex, and body mass index found that transverse sinus stenosis significantly predicted Chiari I malformation versus control status (odds ratio, 11.2 [95% CI, 2.1-59.0]; p = 0.004) but that no other features were significantly associated with the Chiari I malformation. Patients with Chiari I malformation who had transverse sinus stenosis had significantly greater pituitary flattening than did those without transverse sinus stenosis (p = 0.02).
  
  
  CONCLUSIONS
  Patients with Chiari I malformation have higher likelihood of transverse sinus stenosis, which may reflect associated elevated ICP.
authors.affiliation: 1 Department of Radiology and Imaging Sciences, Emory University School of Medicine, BG22, 1364 Clifton Rd NE, Atlanta, GA 30322.
authors.forename: Amit M
authors.initials: AM
authors.lastname: Saindane
authors.forename: Beau B
authors.initials: BB
authors.lastname: Bruce
authors.forename: Nilesh K
authors.initials: NK
authors.lastname: Desai
authors.forename: Lauren A
authors.initials: LA
authors.lastname: Roller
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Newman
authors.forename: Valérie
authors.initials: V
authors.lastname: Biousse
mesh_terms: D001139:Arnold-Chiari Malformation / Q000150:complications* / Q000473:pathology*; D003251:Constriction, Pathologic; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D020227:Lateral Sinus Thrombosis / Q000209:etiology* / Q000473:pathology*; D008297:Male; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D054064:Transverse Sinuses / Q000473:pathology*
keywords: Chiari malformation; MRI; transverse sinus stenosis