例 1　孕妇 ,2 7岁。G1 P0 停经 32周 ,行常规超声检查。彩超所见 :胎头位于宫体右下方 ,双顶径 84mm,脑中线偏移 ,一侧脑室内可探及 43mm× 16 mm不规则液性暗区 ,枕部颅骨连续性中断 9mm,自中断两端向外延伸呈一 37mm× 79mm半圆形囊状物 ,其内呈均一液性暗区 (图 1)。脊柱位 Example 1 pregnant women, 27 years old. G1 P0 menopause 32 weeks, routine ultrasound. Ultrasonography seen: fetal head located in the lower right corner of the palace, biparietal diameter 84mm, midline deviation, one side of the brain can detect and 43mm × 16mm irregular liquid dark area, occipital skull continuity interrupted 9mm, self-interruption Extending outward at both ends of a 37mm × 79mm semicircular bladders, which showed a homogeneous liquid dark area (Figure 1). Spine position