超声与胎儿MRI对胎儿脊髓神经管畸形的产前检出率比较

Detection rates of prenatal ultrasound versus fetal magnetic resonance imaging in prenatal diagnosis of spinal neural tube defects

背景胎儿脊髓神经管畸形的产前准确诊断相对困难,但意义重大。目的探讨产前超声与胎儿MRI在脊髓神经管畸形产前诊断中的准确性和优缺点。方法收集2018年8月-2020年8月,解放军总医院第一医学中心神经外科门诊接诊的产前超声检查怀疑脊髓神经管畸形的胎儿病例资料,超声诊断后72 h内进一步行胎儿MRI。出生后1个月内行MRI,并以此为标准,评估两种检查手段下脊髓神经管畸形的检出率。结果共纳入疑似脊髓神经管畸形的胎儿35例,随访中29例选择继续妊娠,6例放弃妊娠。已出生胎儿24例,另5例仍在妊娠中。24例胎儿出生后MRI检查显示有脊柱裂17例,脂肪瘤型脊髓拴系12例,单纯型脊髓拴系6例。产前超声对胎儿脊柱裂的检出率高于胎儿MRI[64.7%(11/17)vs 41.1%(7/17)],但对胎儿脂肪瘤型脊髓拴系的检出率低于MRI[58.3%(7/12)vs 75.0%(9/12)],对胎儿单纯型脊髓拴系的检出率也低于MRI[66.7%(4/6)vs 83.3%(5/6)],但组间差异均无统计学意义(P均>0.05)。结论超声对脊柱裂的产前诊断比胎儿MRI更有优势;胎儿MRI对脂肪瘤型脊髓拴系的产前诊断比超声更有优势;两者对单纯型脊髓拴系的产前诊断效果相仿。

Background Accurate prenatal diagnosis of fetal spinal neural tube defects is relatively difficult but is of great clinical significance.Objective To explore the detection rates,advantages and disadvantages of prenatal ultrasound and fetal MRI in the prenatal diagnosis of spinal neural tube defects.Methods From August 2018 to August 2020,fetal cases suspected of spinal neural tube defects admitted to the department of neurosurgery of the First Medical Center of Chinese PLA General Hospital were enrolled in this study.All the cases were followed up,and further fetal magnetic resonance imaging(MRI)was performed within 72 hours after the ultrasound diagnosis.Then MRI was performed within 1 month after birth.The detection rates of prenatal ultrasound and fetal MRI were analyzed based on the post-birth MRI as the gold standard,and the detection rates of both methods in the diagnosis of spinal neural tube deformity were evaluated.Results Totally 35 fetal cases were included in this study.During the follow-up,29 cases chose to continue pregnancy,and 6 cases chose to terminate pregnancy.At the end of the follow-up,24 fetuses were born,and 5 cases were still in pregnancy.After birth,MRI showed spina bifida in 17 fetuses,lipomatous spinal cord in 12 fetuses,and simple spinal cord in 6 fetuses.The detection rates of prenatal ultrasound versus fetal MRI for spina bifida(64.7%[11/17]vs 41.1%[7/17]),for lipomatous tethered cord(58.3%[7/12]vs 75%[9/12]),for simple tethered cord(66.7%[4/6]vs 83.3%[5/6])were different,but the differences were not statistically significant(all P>0.05).Conclusion Prenatal ultrasound has advantages over fetal MRI in the prenatal diagnosis of spina bifida,while fetal MRI has advantages over prenatal ultrasound in the prenatal diagnosis of lipomatous tethered cord;the two methods have a similar performance in the prenatal diagnosis of simple tethered cord.