title: Cervical spinal canal narrowing in idiopathic syringomyelia.
abstract: BACKGROUND
  The cervical spine in Chiari I patient with syringomyelia has significantly different anteroposterior diameters than it does in Chiari I patients without syringomyelia. We tested the hypothesis that patients with idiopathic syringomyelia (IS) also have abnormal cervical spinal canal diameters. The finding in both groups may relate to the pathogenesis of syringomyelia.
  
  
  METHODS
  Local institutional review boards approved this retrospective study. Patients with IS were compared to age-matched controls with normal sagittal spine MR. All subjects had T1-weighted spin-echo (500/20) and T2-weighted fast spin-echo (2000/90) sagittal cervical spine images at 1.5 T. Readers blinded to demographic data and study hypothesis measured anteroposterior diameters at each cervical level. The spinal canal diameters were compared with a Mann-Whitney U test. The overall difference was assessed with a Friedman test. Seventeen subjects were read by two reviewers to assess inter-rater reliability.
  
  
  RESULTS
  Fifty IS patients with 50 age-matched controls were studied. IS subjects had one or more syrinxes varying from 1 to 19 spinal segments. Spinal canal diameters narrowed from C1 to C3 and then enlarged from C5 to C7 in both groups. Diameters from C2 to C4 were narrower in the IS group (p < 0.005) than in controls. The ratio of the C3 to the C7 diameters was also smaller (p = 0.004) in IS than controls. Collectively, the spinal canal diameters in the IS were significantly different from controls (Friedman test p < 0.0001).
  
  
  CONCLUSIONS
  Patients with IS have abnormally narrow upper and mid cervical spinal canal diameters and greater positive tapering between C3 and C7.
authors.affiliation: Department of Neurology, Massachusetts General Hospital, 55 Fruit Street Wang 735, Boston, MA, 02114, USA. astruck@mgh.harvard.edu.
authors.forename: Aaron F
authors.initials: AF
authors.lastname: Struck
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Carrie M
authors.initials: CM
authors.lastname: Carr
authors.affiliation: Department of Radiology, University of California San Francisco, San Francisco, CA, USA.
authors.forename: Vinil
authors.initials: V
authors.lastname: Shah
authors.affiliation: Department of Radiology, University of California San Diego, San Diego, CA, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Hesselink
authors.affiliation: Department of Radiology, University of Wisconsin, Madison, WI, USA.
authors.forename: Victor M
authors.initials: VM
authors.lastname: Haughton
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging*; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007223:Infant; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013130:Spinal Stenosis / Q000000981:diagnostic imaging* / Q000209:etiology*; D013595:Syringomyelia / Q000150:complications* / Q000000981:diagnostic imaging*; D014481:United States; D055815:Young Adult
keywords: CSF flow dynamics; Cerebrospinal fluid; Cervical spinal canal; Idiopathic syringomyelia