超声与MRI联合诊断14例单绒毛膜多胎畸形

Combination of ultrasonography and magnetic resonance image in diagnosing monochorionic multifetal malformations--report of 14 cases

目的探讨超声和MRI联合诊断单绒毛膜多胎妊娠畸形的应用价值。方法产前超声检出14例多胎妊娠畸形，均于超声检查后48h内接受MRI检查，并于分娩或引产后证实。回顾性分析此14例的超声和MRI图象，并与随访结果比较。结果14例多胎妊娠中无心畸胎7例、联体双胎5例、多胎之一消失2例。超声与MRI图像比较：（1）对于无心畸胎和多胎之一消失，超声可以明确诊断且是重要的随访手段；MRI能更清晰显示无心胎儿的器官与结构，并能检测供血胎儿和存活胎儿有无颅内继发改变。（2）对于联体儿，在心脏和血管结构的显示及心功能判断中超声明显优于MRI；在胃泡、肾脏、膀胱、肢体等结构的显示中超声与MRI较一致；在食管、肺、肝脏、肠管等器官的显示超声不如MRI，尤其是颅脑的显示；MRI具有较高软组织分辨力及视野大的特点，可显示较大病变及其与周围组织结构的关系，在联体双胎中可以同时显示两胎儿及两胎儿间的关系。结论产前超声和MRI在诊断单绒毛膜多胎妊娠畸形中各有优劣，两者联合应用诊断价值更高。

Objective To demonstrate the value of combined application of prenatal ultrasonography with fetal magnetic resonance imaging （MRI） in the diagnosis of monochorionic multifetal malformations. Methods Fourteen cases of multifetal malformations, detected by prenatal ultrasonography, received MRI within 48 h afterwards. All diagnosis were confirmed after delivery or mid-term termination. All imaging results of the 14 cases were retrospectively reviewed. Results Among the 14 cases, there were 7 acardias, 5 conjoined twins and 2 demise of multifetuses. Comparing ultrasound with MRI, we found that： （1）In cases with acardia and demise of multifetuses, ultrasound could diagnose correctly and be an important tool for follow-up, while MRI could demonstrate organs and structures of the acardiac recipient more clearly and detect the secondary changes of brain in the donor and survived fetus. （2）In conjoined twins, ultrasound was superior to MRI in demonstrating the structure and function of cardiovascular system; and equivalent to MRI in identifying stomach, kidney, bladder and limbs; but inferior to MRI in identifying esophagus, lung, liver and intestinal, especially in the brain. And MRI could demonstrate two fetuses and the relationship between them in conjoined twins simultaneously. Conclusions Prenatal uhrasonography and MRI have their own advantages and disadvantages in diagnosing monochorionic muhifetal malformations. But the combination of prenatal ultrasonography and fetal MRI may be more valuable.