摘要目的 探讨海马结构(HF)在妊娠中期的形态发育变化以及HF在形态和体积发育上是否存在非对称性.方法 收集2008年1月至2009年6月终止妊娠的胎儿标本46例,胎龄为13 ～ 22周,其中男19例、女27例.使用7.0 T MRI对46例胎儿标本进行胎脑扫描,使用Amira 4.1软件进行HF的三维重建并计算其体积.结果 7.0 T MRI扫描图像显示HF形态非常清晰,妊娠中期胎儿HF形态发育是一个逐渐卷曲的过程.左右两侧HF体积随着孕龄的增加而增大(左侧:rs=0.866,右侧:rs=0.889,均P＜0.01).左侧HF体积为0.211 312 cm3(0.016 293 ～ 0.276 762 cm3),右侧为0.217 693 cm3(0.018 362～0.308 548 cm3),两侧HF体积比较显示胎儿右侧HF体积比左侧大(P＜0.05).结论 妊娠中期胎儿HF体积与孕龄呈正相关,左右两侧HF体积增长存在侧别差异.

abstractsObjective To determine morphological alteration in fetal hippocampal formation (HF) during the mid trimester,and to investigate HF symmetry in terms of morphology and volume.Methods Forty-six fetuses with cessation of gestation (19 males and 27 females,gestation age:13-22 weeks) were collected between January 2008 and June 2009.All the cerebrals were scanned using 7.0 T MRI for obtaining data.Three-dimensional reconstruction of HF was undertaken for computation of the volume via Amira 4.1.Results Morphological development of fetal HF appeared to be gradual curling course during the mid trimester of gestation,as demonstrated by the clear imaging of 7.0 T MRI.In addition,increased gestation age was responsible for enlarged volume of HF at both sides (left:rs=0.8663 ; right:rs=0.889,both P＜0.01).The HF volume was 0.211 312 cm3 (0.016 293-0.276 762 cm3) for the left and 0.217 693 cm3 (0.018 362-0.308548 cm3) for right,respectively.Larger volume of HF was in favor of the right side (P＜0.05),but not the left side.Conclusions Fetal HF volume is positively correlated with gestation age during the mid trimester.HF volumic growth yields distinction in terms of sides.