超声测距法定位中晚孕期胎儿脊髓圆锥位置

目的 通过二维和三维超声测量中晚孕期胎儿脊髓圆锥(CM)末端至骶尾部最后一个骨化中心(CS)的距离来定位CM,探索胎儿期CM位置变化的规律。方法 采用二维超声成像及三维超声表面成像检查孕19~34周566名孕妇,测量胎儿CS距离。采用3D容积存储系统存储图像、real-time 3D View软件离线分析,采用组内相关系数(ICC)评价二维与三维超声检测CS距离的一致性。分析胎儿期各孕周CS距离变化规律。结果 共253名二维与三维超声成像测量的CS距离一致性好(ICC=0.974)。CS距离与胎儿孕周呈正相关(r=0.956,P<0.001),线性回归方程为:Y=0.262X-2.508(Y:CS距离,X:孕周)。结论 三维超声表面成像测量CS距离的方法简单有效,适用于临床;CS距离与胎儿GA间的相关性可作为胎儿期CM是否低置的判断标准。

Measuring distance ultrasonics method locating fetal conus medullaris in second and third trimester

Objective To explore the changing regular pattern of conus medullaris (CM) position in second and third trimester through measuring the distance from the end of to the last sacrococcygeal ossification center (CS) with two-dimensional and three-dimensional ultrasuond.Methods Totally 566 pregnant women,19 to 34 weeks gestation,underwent two-dimensional ultrasonic imaging and three-dimensional ultrasonic surface imaging.Three-dimensional volume data was collected and real-time 3D view post-processing software was offline analyzed.Intra-class correlation coefficient (ICC) test was used to analyzing the consistency of the results of two-dimensional and three-dimensional ultrasonics.The changing regular pattern of CS distance in deferent gestation was assessed.Results There were 253 cases which had good consistency of two-dimensional and three-dimensional ultrasonics in measuring CS distance (ICC=0.974).The correlation between CS distance and gestational age was positive (r=0.956,P<0.001).The linear regression equation was Y=0.262X-2.508(Y:distance,X:gestational age).Conclusion The measurement of CS distance with three-dimensional ultrasonic surface imaging is simple,effective and suitable for clinic.The correlation between CS distance and gestational age can be used as a judgment standard about whether fetal CM is low.