超声诊断胎儿胼胝体缺失的价值

The Value of Ultrasound in the Diagnosis of Agenesis of the Corpus Callosum

目的:探讨胎儿胼胝体缺失声像图特征,认识超声在诊断胼胝体缺失中的价值。材料与方法:根据胎位不同,对胎头进行不同切面扫查,以显示胎头矢状切面为最佳,根据颅内结构的直接或间接影像明确诊断。结果:共8例患者经产前超声检查诊断为此类畸形。共同特征为:脑中线居中,双侧脑室前角狭窄,距脑中线距离增宽,后角扩张,整个侧脑室成"泪滴状";双侧脑室成平行状;第三脑室扩张并上移;未见透明隔腔及胼胝体;侧脑室与脑中线之间显示脑回回声。8例均经MRI证实超声诊断。脐带血检查结果示1例染色体异常,为47,XN,+18;余7例为46,XN。结论:胼胝体缺失是一种少见的脑部异常,可以发生在染色体异常病例中。通过产前超声检查对胎儿颅内结构特点进行分析,能够明确诊断此病,对临床工作具有指导意义。

Purpose：To explore the value of ultrasound in the diagnosis of agenesis of the corpus callosum according to analyzing the ultrasound appearence.Materials and Methods：Different sections were selected according to the different fetal position to display the anteroposterior section of fetal head and to make the diagnosis according to the direct or indirect imaging features of the intracranial structure.Results：8 patients were diagnosed as agenesis of the corpus callosum by prenatal ultrasound and were all proved by MRI.The cord blood examination showed that 7 of them had normal chromosomal phenotype while the other 1 was innormal as 47,XN,＋18.The mutual feasures found by ultrasound were discribed as follow.The narrrow anterior horn whose distance to brain middle was lengthed and the dilated posterior horn made lateral ventricle tear-shaped and the hibateral lateral ventricle were parallel.The 3rd ventricle was dilated and its position was moved upward.No structure resembling the camera septi pellucidi and the corpus callosum cound be seen and the cerebral convolution was showed between lateral ventricle and brain middle.Conclusion：Agenesis of the corpus callosum was a rare abnormality of pars encephalica and can concurrence with chromosome aberration.We can diagnose this abnormality directly with ultrasound through the careful analysis of fetal intracranial structure and provide useful information to physicians.