探讨颅脑五横切面法在筛查胎儿颅脑畸形中的临床应用价值。

选取2018年1月至2019年12月期间来深圳市妇幼保健院超声科进行Ⅲ级超声检查的孕妇，采用颅脑五横切面法（3个传统筛查切面+颅顶部横切面+经胼胝体膝部和压部横切面）筛查胎儿中枢神经系统畸形。分析五横切面法检出的中枢神经系统畸形，并与传统的常规筛查平面进行比较。

研究期间共2394例孕妇进行了颅脑5个横切面扫查，共筛查出227例胎儿的400处颅脑异常。在3个传统筛查平面上筛查出115例（50.7%）胎儿的282处颅脑异常。新增的2个平面为其余112例（49.3%）胎儿的118处颅脑畸形提供了额外的诊断信息。其中27例（11.9%）胎儿的颅内异常仅在新增的2个切面上有异常超声表现。这些异常包括胼胝体结构异常、灰质异位、颅内出血、脑裂畸形、脉络丛囊肿、脑穿通畸形和蛛网膜囊肿。在64例存在脑沟回发育异常的胎儿中，在颅顶部横切面上发现45例（45/64，70.3%）顶枕沟异常。9例脑白质软化病例中，7例（7/9，77.8%）涉及半卵圆中心，在颅顶部横切面上有典型的异常超声表现。在60例胼胝体异常的病例中，12例（12/60，20.0%）仅在经胼胝体膝部和压部横切面上有表现，同时这个切面可为35例（35/35，100%）孤立性透明隔和透明隔腔异常作排除性诊断。

颅脑五横切面法可以增加胎儿中枢神经系统异常的检出，建议将五横切面法作为常规筛查策略列入日常胎儿畸形超声检查工作中。

To explore the clinical value of five axial planes of the fetal brain for detecting central nervous system (CNS) malformations.

All pregnant women who visited our center for a Level Ⅲ ultrasound scan were examined using five axial planes (the transcalvarial and trans-genu-and-splenium planes added to three traditional routine screening planes) to screen CNS malformations between January 2018 and December 2019. The types of CNS malformations detected using the five axial planes were analyzed and compared with those detected using the traditional routine screening planes.

During the research period, 2394 pregrant women underwent an evaluation of the fetal brain in the five preselected planes. In this cohort, 227 (9.5%) fetuses presented with 400 cerebral malformations. A total of 282 cerebral malformations in 115 (50.7%) fetuses were diagnosed using the three traditional planes. The other two planes provided additional diagnostic information in the remaining 112 (49.3%) fetuses with 118 cerebral malformations. Among them, 27 (11.9%) fetuses had abnormal manifestations only in the newly added planes, including agenesis of the corpus callosum (ACC), heterotopia, brain hemorrhage, schizencephaly, choroid plexus cyst, porencephaly, and arachnoid cyst. Of the 64 cases with abnormal development of cortical sulci, 45 showed abnormal parieto-occipital fissure in the transcalvarial plane. Seven of the nine cases with leukomalacia involving the centrum semiovale showed typical ultrasound findings in the transcalvarial plane. Of the 60 cases with ACC, 12 were diagnosed in the trans-genu-and-splenium plane, and this plane was also used to exclude the diagnosis of ACC in 35 cases with isolated abnormal septum pellucidum/cavum septum pellucidum.

The detection rate of fetal CNS abnormalities could be improved by using five axial planes. It is recommended that these planes be added for routine CNS malformation screening.