title: MR evaluation of dural ectasia in Marfan syndrome: reassessment of the established criteria in children, adolescents, and young adults.
abstract: OBJECTIVE
  To retrospectively evaluate known criteria for assessment of dural ectasia by using magnetic resonance (MR) imaging in children, adolescents, and young adults with and those without Marfan syndrome.
  
  
  METHODS
  Local ethics committee approval and informed consent were obtained. MR images of the lumbar spine in 28 patients with clinically proved Marfan syndrome (group A; 17 male, 11 female; age range, 4-21 years; mean, 12.1 years), seven patients with suspicion of Marfan syndrome (group B; six male, one female; age range, 6-18 years; mean, 10.4 years), and 55 patients without Marfan syndrome (group C; 26 male, 29 female; age range, 4-20 years; mean, 10.7 years) were evaluated retrospectively for dural ectasia criteria (scalloping, dural sac ratio, nerve root sleeve diameter, sagittal dural sac width at S1 greater than that at L4) and according to classifications by Ahn et al and Fattori et al. For statistical comparison of results, one-way analysis of variance with Scheffe post hoc comparisons was used, with an overall two-tailed significance at alpha = .05.
  
  
  RESULTS
  No significant differences in scalloping and nerve root sleeve diameter were shown between groups. A significant difference was measured for dural sac ratios at L5 and S1 (F test, P = .003 and P < .001 at L5 and S1, respectively; post hoc t test for groups A vs C, P = .004 and P < .001 at L5 and S1, respectively). Significant differences were also obtained between groups A and C for sagittal dural sac width at S1 greater than that at L4 according to the calculated mean difference (for both F test and post hoc t test, P < .001 and P = .003 at S1 and L4, respectively). The Ahn et al and Fattori et al classifications were of limited value.
  
  
  CONCLUSIONS
  The data suggest that only dural sac ratio at L5 and S1 and a sagittal dural sac width at S1 greater than that at L4 are statistically significant criteria for the assessment of dural ectasia in children, adolescents, and young adults.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany. c.habermann@uke.uni-hamburg.de
authors.forename: Christian R
authors.initials: CR
authors.lastname: Habermann
authors.forename: Florian
authors.initials: F
authors.lastname: Weiss
authors.forename: Volker
authors.initials: V
authors.lastname: Schoder
authors.forename: Miriam C
authors.initials: MC
authors.lastname: Cramer
authors.forename: Joern
authors.initials: J
authors.lastname: Kemper
authors.forename: Oliver
authors.initials: O
authors.lastname: Wittkugel
authors.forename: Gerhard
authors.initials: G
authors.lastname: Adam
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D002648:Child; D002675:Child, Preschool; D004108:Dilatation, Pathologic; D004388:Dura Mater / Q000473:pathology*; D005260:Female; D006801:Humans; D008161:Lumbosacral Region; D008279:Magnetic Resonance Imaging; D008297:Male; D008382:Marfan Syndrome / Q000175:diagnosis*; D012189:Retrospective Studies; D013126:Spinal Nerve Roots / Q000473:pathology