Nemescu Dragos, Adam Ana Maria, Tanasa Ingrid Andrada, Socolov Demetra, Bohiltea Roxana Elena, Navolan Dan Bogdan, Zvanca Mona Elena
Department of Obstetrics and Gynecology, 'Grigore T. Popa' University of Medicine and Pharmacy, 700115 Iasi, Romania.
'Euromedicenter' Medical Centre, 700469 Iasi, Romania.
Exp Ther Med. 2020 Sep;20(3):2475-2480. doi: 10.3892/etm.2020.8803. Epub 2020 May 28.
The objective was to have a quantitative description of the normal position of the fetal midbrain in the first trimester, through defining the reference ranges for the mesencephalon to the occipital bone distance, in the axial plane. This was a prospective study that included normal fetuses screened between 11 and 13 weeks of gestation. The distance was measured between the posterior limit of the mesencephalon to the occipital bone in the same axial view as the one required for the biparietal diameter (BPD) assessment, at this gestational age (GA). The reference ranges using quantile regression, according to the crown-rump length (CRL), BPD, and GA were fitted. Data analysis included 428 ultrasound measurements. A good, linear correlation was observed between mesencephalon to occiput (MO) distance and CRL, BPD, or GA. It increased linearly with advancing gestation (logMO = -0.1834 + 0.0092 x CRL, R=0.48, P<0.0001) and was independent of maternal demographic characteristics and intracranial translucency (IT). In our study, the 1st percentile of the normal MO distance varies from 1.31 mm at a CRL of 45 mm to 2.08 mm at a CRL of 84 mm. The intraclass correlation coefficient (ICC) was 0.89 for intraobserver variability. A significant increase in the MO distance was found in the patients who did not receive folic acid in the first trimester of pregnancy [1.056 vs. 1.008 multiple of median (MoM), P=0.014]. A simple measurement is described between the midbrain and the occipital bone, obtained in the same axial view. It increases linearly with advancing gestation. Integration of this measurement into the routine ultrasound screening in association with the 'crash sign' and recognizing the lower extreme values could lead to an early diagnosis of open spina bifida (OSB).
目的是通过定义中脑至枕骨距离在轴平面上的参考范围，对孕早期胎儿中脑的正常位置进行定量描述。这是一项前瞻性研究，纳入了孕11至13周期间筛查的正常胎儿。在评估双顶径（BPD）所需的同一轴位视图中，于该孕周（GA）测量中脑后缘至枕骨的距离。根据顶臀长（CRL）、BPD和GA，使用分位数回归拟合参考范围。数据分析包括428次超声测量。观察到中脑至枕骨（MO）距离与CRL、BPD或GA之间存在良好的线性相关性。其随孕周增加呈线性增加（logMO = -0.1834 + 0.0092 x CRL，R = 0.48，P < 0.0001），且与孕妇人口统计学特征和颅内透明层（IT）无关。在我们的研究中，正常MO距离的第1百分位数在CRL为45 mm时为1.31 mm，在CRL为84 mm时为2.08 mm。观察者内变异的组内相关系数（ICC）为0.89。在孕早期未服用叶酸的患者中发现MO距离显著增加[中位数倍数（MoM）为1.056对1.008，P = 0.014]。描述了一种在同一轴位视图中获得的中脑与枕骨之间的简单测量方法。它随孕周增加呈线性增加。将此测量纳入常规超声筛查，结合“撞击征”并识别较低的极值，可能会导致开放性脊柱裂（OSB）的早期诊断。
