3Wax JR, Pinette MG, Cartin A, et al. Fetal cerebral ventricular pointing as a marker of spina bifida: incidence and observational. J Ultrasound Med,2009,28(3) :317 -320.
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. Uhrasound Obstet Gynecol, 2007,29 ( 1 ) : 109 - 116.
5Koktener A, Dilmen G, Kurt A. The cisterna magna size in normal second-trimester fetuses. J Perinat Med ,2007,35 ( 3 ) :217 - 219.
6Serhatlioglu S,Koeakoc E, Kiris A,et al. Sonographic measurement of the fetal cerebellum,cisterna magna,and ea',um septum pellucidum in normal fetuses in the second and third trimesters of pregnancy. J Clin Ultrasound .2003.31 ( 4 ) : 194 - 200.
7Hollaender R, Hartl F, Krieg MA, et al. Prospective evaluation of risk of vertebral fractures using quantitative ultrasound measurements and bone mineral density in a population-based sample of postmenopausal women:re- sults of the Basel Osteoporosis Study [J]. Ann Rheum Dis,2009,68(3) :391-396.
8Lin Y J, Chai HM, Wang SF. Reliability of thickness measurements of the dorsal muscles of the upper cervical spine:an ultrasonographic study [J]. J Orthop Sports Phys Ther, 2009,39(12) : 850-857.
9Marhofer P,Greher M,Kapral S. Ultrasound guidance in regional anaesthesia [ J ]. Br J Anaesth, 2005,94( 1 ) : 7-17.
10Carvalho JC. Ultrasound-facilitated epidurals and spinals in obstetrics[J]. Anesthesiol Clin,2008,26( 1 ) : 145-158.
