title: Fetal Cerebellar Vermis Circumference Measured by 2-Dimensional Ultrasound Scan: Reference Range, Feasibility and Reproducibility.
abstract: Purpose:To provide 2-dimensional ultrasonographic (2D-US) normograms of cerebellar vermis biometry, as well as to evaluate the feasibility and the reproducibility of these measurements in clinical practice.Materials and Methods:A prospective cross-sectional study of 328 normal singleton pregnancies between 18 and 33 weeks of gestation. Measurements of the fetal cerebellar vermis circumference (VC) in the mid-sagittal plane were performed by both a senior and a junior operator using 2D-US. VC as a function of gestational age (GA) was expressed by regression equations. In 24 fetuses 3-dimensional (3D) reconstructed planes were obtained in order to allow comparisons with 2D-US measurements. The agreement between 2D and 3D measurements and the interobserver variability were assessed by interclass correlation coefficients (ICC).Results:Satisfactory vermis measurements could be obtained in 89.9% of cases. The VC (constant= - 12.21; slope=2.447; r=0.887, p<0.0001) correlated linearly with GA. A high degree of consistency was observed between 2D and 3D ultrasound measurements (ICC=0.846 95% CI 679-0.930) as well as between measurements obtained by different examiners (ICC=0.890 95% CI 989-0.945).Conclusion:2-dimensional ultrasonographic measurements of cerebellar vermis throughout gestation in the mid-sagittal view seem to be feasible and reproducible enough to be potentially used in clinical practice. Such measurements may supply a tool for accurate identification of posterior fossa anomalies, providing the basis for proper counseling and management and of these conditions.
authors.affiliation: Department of Clinical Research, Prenatal Medicine, Inselspital Bern Universitatsklinik fur Frauenheilkunde, Bern, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Spinelli
authors.affiliation: Obstetrics and Gynecology, Private Centre "Diagnostica ecografica e prenatale Aniello Di Meglio s.r.l.", Naples, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Sica
authors.affiliation: Obstetrics and Gynecology, Private Centre "Diagnostica ecografica e prenatale Aniello Di Meglio s.r.l.", Naples, Italy.
authors.forename: L D
authors.initials: LD
authors.lastname: Meglio
authors.affiliation: OB/GYN, University of Bern, Bern, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Bolla
authors.affiliation: OB/GYN, University of Bern, Bern, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Raio
authors.affiliation: OB & GYN, Inselspital, Bern, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Surbek
keywords: cerebellar vermis; prenatal diagnosis; ultrasound 2D