MRI检测小脑延髓池宽度对胎儿后颅凹异常的评估价值

Value of detection of cerebellar cistern width with MRI in evaluating fetal posterior fossa abnormality

目的探讨MRI检测小脑延髓池宽度对胎儿后颅凹异常的评估价值。方法选择本院产科疑诊为胎儿后颅凹发育异常孕妇189例,孕周24~36 w,均进行MRI检查,分析胎儿小脑延髓池宽度对后颅凹发育畸形及预后的影响。结果 189例胎儿中,小脑延髓池宽度<8.0、8~10、>10 mm者各69、88和32例。>10 mm者包括单纯性小脑延髓池扩张27例,非单纯性小脑延髓池扩张5例(枕大池蛛网膜囊肿4例,丹瓦畸形1例)。产后经超声或MRI随访,<8.0、8~10、>10 mm组中,各2例(2.9%)、5例(5.7%)和10例(31.3%)存在后颅凹畸形,>10 mm组后颅凹畸形比例显著高于<8.0和8~10 mm组(P<0.05)。<8.0、8~10、>10 mm组胎儿产后大运动、精细活动、认知功能、语言功能及社交功能评分依次由高到低,具有统计学差异(P<0.05)。结论 MRI可以清晰显示小脑延髓池结构,并进行准确的径线测量。当胎儿小脑延髓池宽度增大至>10 mm时,胎儿发生后颅凹畸形异常和产后发育低下的概率明显增加。

Objective To explore the value of detection of cerebellar cistern width with MRI in evaluating fetal posterior fossa abnormality. Methods A total of 189 pregnant women（24-36 gestational weeks） suspected with abnormal development of fetal posterior fossa in our hospital were selected and received MRI examination to analyze the impact of cerebellar cistern width on the developmental malformation of posterior fossa and the prognosis. Results Among the 189 fetus, there were 69, 88 and 32 fetus with a cerebellar cistern width 8.0, 8-10 and 10 mm respectively. There were 27 cases of pure cerebellar cistern expansion and five cases of non-pure cerebellar cistern expansion（one case of cisterna magna arachnoid cyst and four cases of Danva＇s malformation） among those 10 mm. According to postpartum ultrasound or MRI follow-up visit, in the groups 8.0, 8-10 and 10 mm, there were two cases（2.9%）, five cases（5.7%） and 10 cases（31.3%） of posterior fossa malformation respectively. The proportion of posterior fossa malformation in 10 mm group was significantly higher than that in the groups 8.0 and 8-10（P 〈 0.05）. The postpartum gross motor,fine activity, cognitive function, language function and social function scores in fetus in the groups 8.0, 8-10 and 〉10 mm were from high to low, showing statistical difference（P 〈 0.05）. Conclusion MRI can clearly show the structure of cerebellar cistern and carry out accurate radial line measurement. When the cerebellar cistern width is increased to 〉10 mm, the probability of malformation and poor postpartum development is markedly increased.