产前超声与胎儿磁共振成像在脂肪瘤型脊髓拴系综合征脊髓圆锥定位中的应用

Application of prenatal ultrasound and fetal magnetic resonance imaging in the positioning of conus medullaris for lipoma-type tethered cord syndrome

目的初步探讨产前超声与胎儿MRI在脂肪瘤型脊髓拴系综合征(TCS)脊髓圆锥定位中的应用情况。方法回顾性分析2018年8月至2021年1月解放军总医院第一医学中心神经外科门诊接诊产前诊断为TCS且出生后MRI证实为脂肪瘤型TCS的17例胎儿产前及出生后的影像学资料。以出生后的MRI检查结果为诊断标准,采用Fisher精确概率法分析比较产前超声与胎儿MRI定位脂肪瘤型TCS脊髓圆锥的准确性。结果17例脂肪瘤型TCS胎儿产后诊断为尾侧型4例,背侧型2例,过渡型2例,混杂型8例,脂肪瘤脊髓脊膜膨出型1例。产前超声与胎儿MRI定位脊髓圆锥均符合者共5例,其中尾侧型1例,混杂型4例;均不符合者8例,其中尾侧型2例,过渡型2例,混杂型3例,脂肪瘤脊髓脊膜膨出型1例。出生后1个月的MRI检查证实,产前超声定位脊髓圆锥的准确比例为5/17,胎儿MRI定位脊髓圆锥的准确比例为9/17,二者比较差异有统计学意义(P=0.029)。结论初步观察发现,胎儿MRI定位脂肪瘤型TCS脊髓圆锥的准确性优于产前超声。

Objective To preliminarily explore the clinical application of prenatal ultrasound and fetal MRI in positioning the conus medullaris for lipoma-type tethered cord syndrome(TCS).Methods A retrospective analysis was conducted on the prenatal and postnatal imaging data of 17 fetuses with prenatal diagnosis of TCS and confirmed diagnosis of lipoma-type TCS based on postnatal MRI follow-up who visited the outpatient clinic of Neurosurgery Department,the First Medical Center of PLA General Hospital from August 2018 to January 2021.Based on the results of MRI examination after birth,Fisher's exact test was used to analyze and compare the accuracy of prenatal ultrasound with fetal MRI in locating the conus medullaris in lipoma-type TCS.Results Among 17 cases of lipoma-type TCS,4 cases were terminal,2 cases were dorsal,2 cases were transitional,8 cases were chaotic,and 1 case was lipomyelomeningocele.In 5 cases,both prenatal ultrasound examination and fetal MRI examination demonstrated accurate location of the conus medullaris,of which 1 case was terminal and 4 cases were chaotic.In 8 cases,neither prenatal ultrasound nor fetal MRI result was accurate,of which 2 cases were terminal,2 cases were transitional,3 cases were chaotic,and 1 case was lipomyelomeningocele.An MRI examination at 1 month after birth revealed that the accuracy ratio of prenatal ultrasound examination in positioning the conus medullaris was 5/17 and that of fetal MRI examination was 9/17;the difference was statistically significant(P=0.029).Conclusion Positioning of the conus medullaris in lipoma-type TCS using fetal MRI is more accurate than that based on ultrasound.