title: Quantitative evaluation of fetal brainstem-vermis and brainstem-tentorium angles by three-dimensional ultrasound.
abstract: The aim of this study was to determine reference values and ranges for brainstem-vermis (BV) angle and brainstem-tentorium (BT) angle and to assess the correlation among these angles, fetal gender and gestational age (GA) in 221 fetuses between 20 and 37 wk. The angles of the BV and BT were measured on the mid-sagittal view of the fetal head in normally developed Chinese fetuses. The ultrasound measurements, the fetal gender and the GA were collected for statistical analysis. Rank sum test revealed no significant differences in the measurements of the BV and the BT angles with respect to gender (all p > 0.05). Spearman rank correlation analysis showed no GA effect on the BV and the BT angles with correlation coefficients (r) of 0.05 (p > 0.05) and 0.09 (p > 0.05). The 95% reference ranges of the BV and the BT angles were 8.7° (4.5°-18.0°) and 28.0° (21.3°-43.8°), respectively. The newly established reference ranges may facilitate differential diagnosis of fetuses with suspected posterior fossa anomalies in the second and third trimesters.
authors.affiliation: Department of Ultrasound, Shengjing Hospital of China Medical University, Shenyang, China.
authors.forename: Xinyue
authors.initials: X
authors.lastname: Meng
authors.affiliation: Department of Ultrasound, Shengjing Hospital of China Medical University, Shenyang, China. Electronic address: xielm72@aliyun.com.
authors.forename: Limei
authors.initials: L
authors.lastname: Xie
mesh_terms: D000328:Adult; D001933:Brain Stem / Q000000981:diagnostic imaging*; D002681:China; D005069:Evaluation Studies as Topic; D005260:Female; D005865:Gestational Age; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D015588:Observer Variation; D011247:Pregnancy; D011446:Prospective Studies; D012016:Reference Values; D017678:Sex Distribution; D016216:Ultrasonography, Prenatal / Q000379:methods*
keywords: Brainstem–tentorium angle; Brainstem–vermis angle; Posterior fossa malformations; Reference ranges; Three-dimensional ultrasound