超声定位中孕期胎儿脊髓圆锥末端位置的价值

Value of Ultrasonic Localization of Fetal Conus Medullaris Termination in Second Trimester

目的通过计算脊髓圆锥末端到骶尾部最后一个骨化中心之间的椎体个数来定位脊髓圆锥位置,探讨超声在中孕期快速定位胎儿脊髓圆锥末端位置的临床价值。方法以408例正常孕妇作为研究对象,对胎儿采用二维超声检查并计算脊髓圆锥末端至骶尾部最后一个骨化中心之间的椎体个数。当椎体个数≥7时,为胎儿脊髓圆锥位置正常;当椎体个数≤6时,采用腰骶前突定位法定位脊髓圆锥末端水平对应的腰椎椎体位置。结果 408例孕妇中,341例的椎体个数≥7;67例的椎体个数=6,经腰骶前突定位法,脊髓圆锥末端位于L3—L4的有4例(6.0%),位于L3以上的有63例(94.0%)。结论超声可清晰显示脊髓圆锥末端位置,通过快速计数脊髓圆锥末端至骶尾部最后一个骨化中心之间的椎体数,可快速判断胎儿脊髓圆锥末端的位置。当椎体个数=6时,发生脊髓栓系综合征(TCS)的风险低;当椎体个数<6时,应做进一步的检查。

Objective To locate the position of conus medullaris by calculating the number of vertebral bodies between the conus medullaris termination and the last ossification center of sacrococcygeal region,and to investigate the clinical value of ultrasound in rapid positioning of fetal conus medullaris termination.Methods The number of vertebral bodies between the conus medullaris termination and the last ossification center of sacrococcygeal region was calculated by two-dimensional ultrasound examination in 408 normal pregnant women.When the number of vertebrae was≥7,the position of conus medullaris was considered normal.When the number of vertebrae was≤6,the lumbosacral protrusion positioning method was used to locate the lumbar vertebral body position which was horizontal with conus medullaris termination.Results Among 408 pregnant women,the vertebral body number was greater than or equal to 7 in 341,and equal to 6 in 67.Lumbosacral protrusion positioning showed that the conus medullaris termination was located at L3-L4 in 4 cases(6.0%)and above L3 in 63 cases(94.0%).Conclusion Ultrasound examination clearly displays the position of conus medullaris termination,which can be quickly determined by calculating the number of vertebral bodies between the conus medullaris termination and the last ossification center of sacrococcygeal region.The risk for tethered cord syndrome is low when the number of vertebrae is equal to 6.However,further examination should be performed when the number of vertebrae is less than 6.