title: Fetal cerebral ventricular pointing as a marker of spina bifida: incidence and observational agreement.
abstract: OBJECTIVE
  Occipital cerebral ventricular pointing is a promising intracranial marker for spina bifida. We sought to determine (1) the incidence of pointing in fetuses with and without spina bifida and (2) inter-observer and intraobserver agreement for visualizing pointing.
  
  
  METHODS
  Second-trimester transverse axial images of the lateral cerebral ventricles from an equal number of affected and unaffected fetuses were independently reviewed in a blinded fashion by 2 examiners.
  
  
  RESULTS
  Sixty-two fetuses (31 with isolated spina bifida and 31 without) had sonographic examinations at 19.2+/-1.3 weeks (mean+/-SD). Pointing was present in 77.3% of fetuses with spina bifida and 15% of those without by the first examiner and in 78.3% of fetuses with spina bifida and 10% of those without by the second examiner. Interobserver and intraobserver agreement were substantial (kappa=0.69 and 0.78, respectively).
  
  
  CONCLUSIONS
  Ventricular pointing is a highly agreed-on finding that is substantially associated with but not pathognomonic for fetal spina bifida.
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Maine Medical Center, Portland, Maine 04102, USA. waxj@mmc.org
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Wax
authors.forename: Michael G
authors.initials: MG
authors.lastname: Pinette
authors.forename: Angelina
authors.initials: A
authors.lastname: Cartin
authors.forename: Janet
authors.initials: J
authors.lastname: Michaud
authors.forename: Jacquelyn
authors.initials: J
authors.lastname: Blackstone
mesh_terms: D002552:Cerebral Ventricles / Q000000981:diagnostic imaging* / Q000196:embryology*; D004453:Echoencephalography / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D008281:Maine / Q000453:epidemiology; D008297:Male; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016135:Spinal Dysraphism / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D016216:Ultrasonography, Prenatal / Q000706:statistics & numerical data*