Fetal Medicine Unit, Di Venere and Sarcone Hospitals, ASL BA, Bari, Italy.
Department of Obstetrics and Gynecology, University of Bologna, Bologna, Italy.
Ultrasound Obstet Gynecol. 2016 Jun;47(6):720-5. doi: 10.1002/uog.14883.
To describe the sonographic appearance of fetal posterior fossa anatomy at 11-14 weeks of pregnancy and to assess the outcome of fetuses with increased intracranial translucency (IT) and/or brainstem-to-occipital bone (BSOB) diameter.
Reference ranges for brainstem (BS), IT and cisterna magna (CM) measurements, BSOB diameter and the BS : BSOB ratio were obtained from the first-trimester ultrasound examination of 233 fetuses with normal postnatal outcome (control group). The intraobserver and interobserver variability of measurements were investigated using 73 stored ultrasound images. In addition, a study group of 17 fetuses with increased IT and/or BSOB diameter was selected to assess outcome.
No significant intraobserver or interobserver variability was found for any measurement in the control group. In the study group, IT was increased in all cases and BSOB diameter was above the 95(th) centile of the calculated normal range in all but two (88%) cases. In 13/17 study cases, only two of the three posterior brain spaces were recognized on ultrasound. These 13 fetuses had a larger BSOB diameter than did the four cases that showed all three posterior brain spaces, and had severe associated anomalies including Dandy-Walker malformation (DWM) and/or chromosomal anomalies.
Visualization of the fetal posterior fossa anatomy at 11-14 weeks' gestation is feasible. Increased fluid in the posterior brain at 11-14 weeks, particularly in the case of non-visibility of the septation that divides the future fourth ventricle from the CM, is an important risk factor for cystic posterior fossa malformations, in particular DWM, and/or chromosomal aberrations. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
描述 11-14 孕周胎儿后颅窝解剖结构的超声表现，并评估颅内透明层（IT）和/或脑桥至枕骨骨（BSOB）直径增加的胎儿的结局。
从 233 例具有正常产后结局的胎儿（对照组）的早孕期超声检查中获得脑桥（BS）、IT 和脑池（CM）测量值、BSOB 直径和 BS：BSOB 比值的参考范围。使用 73 个存储的超声图像研究了测量的观察者内和观察者间变异性。此外，选择了 17 例 IT 和/或 BSOB 直径增加的研究组来评估结局。
在对照组中，任何测量值均未发现明显的观察者内或观察者间变异性。在研究组中，所有病例的 IT 均增加，除两例（88%）外，BSOB 直径均高于计算正常范围的第 95 百分位数。在 17 例研究病例中，仅在超声上识别出三个后颅空间中的两个。这 13 例胎儿的 BSOB 直径大于仅显示三个后颅空间的四个病例，并且存在严重的相关异常，包括 Dandy-Walker 畸形（DWM）和/或染色体异常。
在 11-14 孕周时，胎儿后颅窝解剖结构的可视化是可行的。11-14 周时后颅窝内液体增加，特别是在分隔未来第四脑室和 CM 的分隔不可见的情况下，是囊性后颅窝畸形（特别是 DWM）和/或染色体异常的重要危险因素。版权所有©2015 ISUOG。由 John Wiley & Sons Ltd 出版。
