Robbin M L, Filly R A, Goldstein R B
Department of Radiology, University of Alabama at Birmingham 35233-1924.
J Ultrasound Med. 1994 Jul;13(7):541-6. doi: 10.7863/jum.1994.13.7.541.
In vivo studies of the location of the normal conus medullaris in infancy and childhood have been extended to the fetus utilizing sonography. This prospective study of 33 fetuses showed that the fetal conus medullaris can be visualized in the prone fetus as early as 19 menstrual weeks. By the time the conus medullaris was observed sonographically, its location was within the normal adult range, thus refuting the commonly held notion that the conus medullaris ascends to adult levels sometime in childhood. Our results suggest that a fetal spinal cord termination level of L2-L3 or higher should be considered within normal limits. A termination level of L3 is indeterminate and requires neonatal evaluation. A termination level of L3-L4 or lower is abnormal and should instigate a careful sonographic search for associated abnormalities.
利用超声检查，对婴儿期和儿童期正常脊髓圆锥位置的体内研究已扩展至胎儿。这项对33例胎儿的前瞻性研究表明，早在妊娠19周时，俯卧位胎儿的脊髓圆锥就可通过超声显示。当通过超声观察到脊髓圆锥时，其位置已在正常成人范围内，因此反驳了普遍认为的脊髓圆锥在儿童期某个时候升至成人水平的观点。我们的结果表明，胎儿脊髓终末水平在L2 - L3或更高应被视为正常范围。L3水平的终末情况不确定，需要对新生儿进行评估。L3 - L4或更低的终末水平是异常的，应促使进行仔细的超声检查以寻找相关异常情况。
