2Blas D. Fetal evaluation of spine dysraphism[J]. Pediatri Radiol, 2010.40:1029-1037.
3张金哲,杨启政,刘贵麟.中华小儿科学[M].郑州:郑州大学出版社,2006:309.
4International Society of Ultrasound in Obstetrics & Gynecology Education Committee. Sonographic examination of the fetal central nervous system:guidelines for performing the basic examination and the fetal neurosonogram[J]. Ultrasound Obst Gynecol,2007, 29:109-116.
8Zalel Y,Lehavi O,Aizeinstein O,et al. Development of the fetal spinal cord. Time of ascendance of the normal conus medullaris as detected by sonography[J]. J Ultrasound Med,2006,25:1397- 1401.
9Perlitz Y,Izhaki I,Bcn-Ami M. Sonographie evaluation of the fetal eonus medullaris at 20 to 24 weeks' gestation[J]. Prenat Diagn, 2010,30 : 862-864.