MRI characteristics of the fetal tethered spinal cord: a comparative study

<b>Purpose:</b> To compare fetuses and children with confirmed tethered cord syndrome to age-matched controls to provide a reference for prenatally identifying tethered spinal cord and to identify salient points on MRI for diagnosis. <b>Materials and Methods:</b> This retrospective study enrolled 13 fetuses and 20 children with tethered cord syndrome, and age-matched counterparts were included as controls. The MRI features including concomitant malformations, position of the conus medullaris, and thickened filum terminale of the two patient groups were evaluated and compared. Levels of the conus medullaris were discriminated between patients and an equivalent number of controls. <b>Results:</b> Various concomitant malformations manifested on the MRI of all patients, and there were differences between the two patient groups. Significant differences of the level of the conus medullaris were found between the fetal and child patients (<i>U</i>, 26.50; <i>Z</i>, −3.87; <i>p</i> &lt; 0.001) and between the normal fetus and child controls (<i>U</i>, 23.50; <i>Z</i>, −4.13; <i>p</i> &lt; 0.001). The position of the conus medullaris was visibly lower in the patient groups than in the control groups. No significant difference in the diameters of the filum terminale was found between the fetal and child patients (<i>p</i> = 0.67). <b>Conclusions:</b> The current study<b>’</b>s results indicate that tethered spinal cord syndrome can be diagnosed in utero with MRI combined with several characteristics, particularly the position of the conus medullaris. Special attention should be paid to the gestational age of the fetus because normal changes in spinal cord position occur with gestational development.

<b>研究目的：</b>将确诊脊髓栓系综合征（tethered cord syndrome）的胎儿与儿童患者，与同年龄段对照组进行对比，旨在为产前识别脊髓栓系提供参考依据，并明确MRI诊断该病的关键征象。<b>材料与方法：</b>本回顾性研究共纳入13例确诊脊髓栓系综合征的胎儿患者、20例儿童患者，并设置年龄匹配的对照组。对两组患者的MRI特征进行评估与对比，包括伴发畸形、脊髓圆锥（conus medullaris）位置及终丝（filum terminale）增粗情况；同时对患者组与对应数量对照组的脊髓圆锥位置水平进行鉴别分析。<b>结果：</b>所有患者的MRI影像均可见不同类型的伴发畸形，且两组患者间存在差异。胎儿患者与儿童患者的脊髓圆锥位置水平存在显著统计学差异（<i>U</i>=26.50，<i>Z</i>=-3.87，<i>p</i><0.001）；正常胎儿对照组与正常儿童对照组的脊髓圆锥位置水平亦存在显著统计学差异（<i>U</i>=23.50，<i>Z</i>=-4.13，<i>p</i><0.001）。患者组的脊髓圆锥位置显著低于对照组。胎儿患者与儿童患者的终丝直径无显著统计学差异（<i>p</i>=0.67）。<b>结论：</b>本研究结果表明，结合多项影像学特征，尤其是脊髓圆锥位置，可通过MRI在宫内诊断脊髓栓系综合征。需特别关注胎儿胎龄，因脊髓位置会随妊娠进展发生生理性正常变化。