MR-based morphometry of the posterior fossa in fetuses with neural tube defects of the spine

PLoS One. 2014 Nov 13;9(11):e112585. doi: 10.1371/journal.pone.0112585. eCollection 2014.


Objectives: In cases of "spina bifida," a detailed prenatal imaging assessment of the exact morphology of neural tube defects (NTD) is often limited. Due to the diverse clinical prognosis and prenatal treatment options, imaging parameters that support the prenatal differentiation between open and closed neural tube defects (ONTDs and CNTDs) are required. This fetal MR study aims to evaluate the clivus-supraocciput angle (CSA) and the maximum transverse diameter of the posterior fossa (TDPF) as morphometric parameters to aid in the reliable diagnosis of either ONTDs or CNTDs.

Methods: The TDPF and the CSA of 238 fetuses (20-37 GW, mean: 28.36 GW) with a normal central nervous system, 44 with ONTDS, and 13 with CNTDs (18-37 GW, mean: 24.3 GW) were retrospectively measured using T2-weighted 1.5 Tesla MR -sequences.

Results: Normal fetuses showed a significant increase in the TDPF (r = .956; p<.001) and CSA (r = .714; p<.001) with gestational age. In ONTDs the CSA was significantly smaller (p<.001) than in normal controls and CNTDs, whereas in CNTDs the CSA was not significantly smaller than in controls (p = .160). In both ONTDs and in CNTDs the TDPF was significantly different from controls (p<.001).

Conclusions: The skull base morphology in fetuses with ONTDs differs significantly from cases with CNTDs and normal controls. This is the first study to show that the CSA changes during gestation and that it is a reliable imaging biomarker to distinguish between ONTDs and CNTDs, independent of the morphology of the spinal defect.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Brain / pathology*
  • Case-Control Studies
  • Diagnosis, Differential
  • Female
  • Fetus
  • Gestational Age
  • Humans
  • Image Interpretation, Computer-Assisted*
  • Magnetic Resonance Imaging
  • Pregnancy
  • Prenatal Diagnosis / instrumentation*
  • Retrospective Studies
  • Spina Bifida Cystica / diagnosis*
  • Spina Bifida Cystica / pathology
  • Spina Bifida Occulta / diagnosis*
  • Spina Bifida Occulta / pathology

Grant support

Funding was supported by the Austrian National Bank (OeNB 14812, “Quantitative Morphometrie der fetalen Gehirnentwicklung für Pathologiemodellierung und Diagnose”). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.