扩散加权成像在正常胎儿脑发育中的应用  

Application of Diffusion Weighted Imaging in Evaluating Normal Fetal Brain Development

作　　者：郑昌业 曹满瑞[2] 刘炳光[2] 朱志军[2] 杜牧[2] 张翔亚 

机构地区：[1]广州医科大学,510182 [2]南方医科大学附属深圳市妇幼保健院放射科,518028

出　　处：《临床放射学杂志》2015年第3期440-443,共4页Journal of Clinical Radiology

摘　　要：目的探讨扩散加权成像（DWI）对正常胎儿脑发育的评估价值。方法回顾性分析40例正常胎儿脑DWI表现,孕周19~39周,平均33.6周。在ADC图上分析总结正常胎儿脑表现特征,并测量脑干、双侧小脑半球、基底节区、丘脑、颞叶白质、额叶白质、枕叶白质、半卵圆中心及顶叶白质的ADC值,分析不同部位ADC值随孕周变化的规律。结果在ADC图上,胎儿幕上脑实质表现为信号强度不同的分层状结构,随孕周增加分层减少。双侧大脑半球间对称部位ADC值无显著性差异。幕上深部白质平均ADC值高于小脑半球、脑干及深部灰质核团,顶叶ADC值最高（1.62±0.17）mm/s,脑干ADC值最低（1.08±0.13）mm/s。胎儿脑干、双侧小脑半球、基底节区、丘脑、颞叶白质、枕叶白质、半卵圆中心及顶叶白质ADC值与胎龄呈负相关,小脑半球相关系数最高（r=0.78）,枕叶相关系数最低（r=0.38）,额叶与胎龄无线性相关（P〉0.05）。小脑半球ADC值随胎龄增长下降最快（b=0.03）。结论 DWI可应用于正常胎儿脑发育的评估,为胎儿脑发育的产前诊断及预后提供重要信息。Objective To discuss the value of diffusion weighted imaging（ DWI） in evaluating normal fetal brain development.Methods DWI manifestations of normal fetal brain in 40 normal fetuses were retrospectively analyzed.DWI scanning was performed between 19 and 39 gestation weeks（ mean 33.6 weeks）.The white matter apparent diffusion coefficient（ ADC） values of brainstem,bilateral cerebellum,basal ganglia,thalamus,and white matter of the temporal lobe,frontal lobe,occipital lobe,centrum semiovale and parietal lobe were determined.The correlation between ADC values changes of different sites and gestation weeks was analyzed.Results On ADC map,fetal supratentorial parenchyma showed a multilayered pattern and the layers reduced with the increasing of gestational age.Data obtained from corresponding regions of the left and right hemispheres indicated that no statistically significant difference existed between the two sides.The mean ADC value of supratentorial deep white matter（ DWM） was higher than that of the cerebellar hemisphere,pons as well as those of deep gray nuclei.The mean ADC value of the parietal lobe was the highest（ 1.62 ± 0.17 mm / s）,while the mean ADC value of the pons was the lowest（ 1.08 ± 0.13） mm / s.Gestational age bore a significant negative correlation with the ADC values of the parietal white matter,centrum semiovale,basal ganglia,thalamus,frontal white matter,occipital white matter,temporal white matter,cerebellum and pons.The correlation coefficient of the cerebellum was the highest（ r = 0.78）,while the correlation coefficient of the occipital white matter was the lowest（ r = 0.38）.ADC value of frontal white matter showed no linear correlation with gestational age（ P 〉 0.05）.ADC values of the cerebellum fell fastest with gestational age（ b = 0.03）.Conclusion DWI can be used in evaluating the normal fetal brain development,providing important information for early diagnosis and prognosis of fetal brain development.

关 键 词：胎儿 脑发育 扩散加权成像 表观扩散系数 

分 类 号：R445.2[医药卫生—影像医学与核医学] R714.5[医药卫生—诊断学]