Abstract：
This study aimed to ascertain the conus medullaris position by counting the number of ossification centers in the vertebral bodies below the conus medullaris endpoint (N) and assess its utility in screening for closed spinal dysraphism and tethered cord syndrome.
A total of 900 normal fetuses and 146 fetuses with closed spinal dysraphism or tethered cord syndrome were included in this study. The N values were tallied and compared along the spinal longitudinal plane. The receiver operating characteristic curve was utilized, and the cut-off value of N was analyzed.
The counting of N was successfully performed in 856 normal and 146 abnormal fetuses. In the normal group, an increase in N with gestational age was observed. Specifically, in the subgroup of 17-20 wk fetuses, N was ≥6 in 117 out of 131 cases. This figure increased to 211 out of 213 in 21-24 wk and 512 out of 512 in 25-41 wk, respectively. Cases with N ≥7 accounted for 715 out of 856 fetuses in the 17-41 wk range. In the abnormal group, N was less than 7 in 152 out of 163 fetuses, showing statistical differences between the two groups. With a cut-off value of 6.5, specificity and sensitivity reached 93.3% and 83.5%.
The counting of N was found to be a straightforward and efficient method for evaluating the position of the conus medullaris.
A total of 900 normal fetuses and 146 fetuses with closed spinal dysraphism or tethered cord syndrome were included in this study. The N values were tallied and compared along the spinal longitudinal plane. The receiver operating characteristic curve was utilized, and the cut-off value of N was analyzed.
The counting of N was successfully performed in 856 normal and 146 abnormal fetuses. In the normal group, an increase in N with gestational age was observed. Specifically, in the subgroup of 17-20 wk fetuses, N was ≥6 in 117 out of 131 cases. This figure increased to 211 out of 213 in 21-24 wk and 512 out of 512 in 25-41 wk, respectively. Cases with N ≥7 accounted for 715 out of 856 fetuses in the 17-41 wk range. In the abnormal group, N was less than 7 in 152 out of 163 fetuses, showing statistical differences between the two groups. With a cut-off value of 6.5, specificity and sensitivity reached 93.3% and 83.5%.
The counting of N was found to be a straightforward and efficient method for evaluating the position of the conus medullaris.
摘要：
目的：本研究旨在通过计算延髓圆锥终点（N）以下椎体骨化中心的数量来确定延髓圆锥的位置，并评估其在筛查闭合性脊髓发育不良和脊髓栓系综合征中的作用。
方法：本研究共纳入了900名正常胎儿和146名患有闭合性脊髓发育不良或脊髓栓系综合征的胎儿。沿脊柱纵向平面计算并比较N值。利用接收器工作特性曲线，并对N的截断值进行了分析。
结果：在856例正常胎儿和146例异常胎儿中成功进行了N计数。在正常组,观察到N随胎龄增加。具体来说,在17-20周胎儿亚组中，131例中117例，N≥6。这一数字在21-24周增加到213人中的211人，在25-41周增加到512人中的512人，分别。在17-41周范围内，N≥7的病例占856例胎儿中的715例。在异常组中，在163个胎儿中，N小于7/152，显示两组之间的统计学差异。截断值为6.5，特异性和敏感性分别为93.3％和83.5％。
结论：发现N的计数是评估延髓圆锥位置的一种直接有效的方法。
方法：本研究共纳入了900名正常胎儿和146名患有闭合性脊髓发育不良或脊髓栓系综合征的胎儿。沿脊柱纵向平面计算并比较N值。利用接收器工作特性曲线，并对N的截断值进行了分析。
结果：在856例正常胎儿和146例异常胎儿中成功进行了N计数。在正常组,观察到N随胎龄增加。具体来说,在17-20周胎儿亚组中，131例中117例，N≥6。这一数字在21-24周增加到213人中的211人，在25-41周增加到512人中的512人，分别。在17-41周范围内，N≥7的病例占856例胎儿中的715例。在异常组中，在163个胎儿中，N小于7/152，显示两组之间的统计学差异。截断值为6.5，特异性和敏感性分别为93.3％和83.5％。
结论：发现N的计数是评估延髓圆锥位置的一种直接有效的方法。
