三维超声容积对比成像和断层超声成像技术观察胎儿脊髓栓系

摘要

目的 探讨三维超声容积对比成像(VCI)及断层超声成像(TUI)技术观察胎儿脊髓圆锥(CM)所对应的椎体位置、脊髓腰膨大的大小及形态,评估是否存在胎儿脊髓栓系(TC)的价值.方法 记录病例组17胎脊柱区病变或畸形伴TC胎儿的CM末端位置和腰膨大位置,测量脊髓腰膨大处的横径、前后径.并与300胎正常胎儿进行对比分析.结果 随着孕周的增长CM末端位置上升,300胎正常胎儿的CM末端均位于L3或L3以上椎体水平.正常胎儿脊髓腰膨大的横径和前后径均与孕周有较好的线性关系,线性回归方程为:腰膨大横径(mm)=0.677+0.147×孕周(R2 =0.836,P＜0.05),腰膨大前后径(mm)=-0.994+0.152×孕周(R2=0.894,P＜0.05).与正常胎儿相应孕周正常值比较,病例组TC胎儿脊髓腰膨大的前后径减小(P=0.002),横径差异无统计学意义(P=0.082).结论 通过三维超声VCI及TUI技术对胎儿CM位置进行判定并分析脊髓腰膨大的形态变化,可为TC胎儿的产前诊断提供有价值的参考依据.%Objective To evaluate the value of three-dimensional ultrasound volume contrast imaging (VCI) and tomo graphy ultrasound imaging (TUI) techniques in observing fetal spinal conus medullaris (CM) position and lumbar enlargement of spinal cord morphologic changes,for assessment of tethered cord (TC).Methods Totally 17 abnormal fetuses of spinal diseases combined with TC (abnormal group) were examined by three dimensional ultrasound VCI and TUI techniques.The position of CM was recorded,and the transverse and anteroposterior diameters of lumbar enlargement of spinal cord were measured and compared with 300 cases of normal fetuses (normal group).Results As the growth of the gestational age (CA),CM terminal position increased.All the ends of CM located at L3 or L3 above level in normal.The transverse and anteroposterior diameters of lumbar enlargement in normal group showed good linear relationship with GA.Transverse diameter (mm) =0.677+0.147 ×GA (R2 =0.836,P＜0.05),anteroposterior diameter (mm)-0.994+ 0.152× GA (R2=0.894,P＜0.05).Compared with the corresponding GA fetuses in normal group,the anteroposterior diameter of lumbar enlargement decreased in abnormal group (P=0.002),while no statistical difference of the transverse diameter was found between the two groups (P=0.082).Conclusion Position of CM and lumbar enlargement measure ment can provide valuable reference information for clinical prenatal diagnosis of fetal spinal TC.