胎儿后颅窝积液产前超声影像监测的临床意义

Clinical significance of ultrasonographic imaging observation of Fetal posterior fossa fluid

目的：探讨胎儿后颅窝积液的诊断标准、临床意义及Dandy-Walker综合症的超声特征。方法：产前超声检查胎儿后颅窝池增宽者71例，仔细对胎儿全身部位进行检查，特别观察后颅窝，尤其是小脑结构，每2-3周对后颅窝池及其它情况进行观察直至分娩，其中21例行MRI检查。结果：后颅窝池宽10-14mm 40例，平均12.6±1.8mm，38例胎儿生后均未见异常改变，围产儿不良发生率5%。后颅窝池宽15-37mm 31例，平均21.7±2.7mm，围产儿不良发生率68%，9例羊水过多，其中2例合并室间隔缺损约10mm，4例合并神经系统畸形，3例产后未见异常：12例为神经系统发育异常：4例肾脏发育不良；2例四肢发育短小，其中1例合并心脏畸形、左肾上腺肿块，1例合并双腕内翻畸形；1例胎儿宫内生长迟缓。结论：产前超声可清晰显示胎儿后颅窝情况，后颅窝池10-14mm可为异常，定期随访，15mm时应密切观察，胎儿异常发生率增高。MRI可明确的显示小脑结构以排除合并小脑发育异常的Dandy-Walker综合症。

Objective：To investigate the ultrasonographic diagnosis criteria and clinical value of fetal posterior fossa fluid by uhrasono- graphic imaging observation of cerebellomedullary cistern, the fourth ventricle and the cerebeller structure.Methods： 71 cases of the fetal posterior fossa accumulated fluid were found by prenatal uhrasonography examination and observed specially the fetal posterior fossa and the cerebeller structure. The changes of accumulated fluid in the fetal posterior fossa and the associated intracranial and extracranial anomalies were observed regularly every 2 or 3 weeks until delivery. 21 women among them were examined by MRI. Results： The width of 40 cases of the fetal posterior fossa cistern were from 10 - 14mm and meaned 12.6 ± 1.8mm in average. 38 cases were normal and the incidence of defected infant was 5%. The width of 31 cases of the fetal posterior fossa cistern were 15 - 37mm and raeaned 21.7 ± 2.7mm in average. The incidence of defected infant was 68% with 7 cases in normal neonate. 9 cases were in polyhydramnies, 2 of which with VSD（10mm）, 4 with the nervous system abnorruslity and 3 in normal neonate. 12 cases were in the nervous system abnormality. 4 cases were in renal dysplasia. 2 cases were in limb shortening, among which 1 case were with heart abnormality and adrenal mass and 1 case with both wrists varus. 1 cases were in IUGR. Conclusion：The fetal posterior fossa is demonstrated clearly by ultrasound. The width （10 - 14mm） of the fetal posterior fossa cisteria was considered abnormal and should be regularly followed up. As for width more than 15mm, attention showld be paid and the incidence of fetal abnormality raised up. MPd can clearly demonstrate the cerebreller structure and examine the Dandy-Walker syndrome with cerebreller abnormality.