婴幼儿脑髓鞘发育的MR—DTI研究  

Study on magnetic resonance-diffusion tensor imaging in assessing myelination of normal infants

作　　者：宋旸[1] 蒋昊翔[2] 刘黎明[1] 帖利军[1] 史晓薇[1] 岳婕[1] 胡长江[1] 

机构地区：[1]西安交通大学医学院第一附属医院,陕西西安710061 [2]西安市儿童医院CT室,陕西西安710002

出　　处：《中国妇幼健康研究》2012年第3期256-259,共4页Chinese Journal of Woman and Child Health Research

摘　　要：目的探讨磁共振弥散张量成像（MR—DTI）在婴幼儿脑髓鞘发育中的应用价值。方法48例无中枢神经系统疾病，颅脑MR检查未见异常的足月婴幼儿按照年龄段分为6组（0—28天组6例、29天－3个月组6例、4．6个月组5例、7．12个月组13例、13～18个月组9例、19—24个月组9例），分别行DTI检查，测定不同部位的部分各向异性指数和平均弥散系数。感兴趣区（ROI）包括周围白质（双侧额叶、顶叶、半卵圆中心）、深部白质（双侧内囊前、后肢及胼胝体膝部、压部）和深部灰质（双侧尾状核、豆状核及丘脑）。分析DTI参数值在婴幼儿脑髓鞘发育中的变化规律。结果豆状核及尾状核除外，脑其余部位的各向异性指数值与年龄呈显著正相关（r值均〉0．74，P〈0．001），且随年龄增长呈对数样增高；脑所有感兴趣区的平均弥散系数值与年龄呈显著负相关（r值均〈－0．74，P〈0．001），且随年龄增长呈对数样降低。各年龄段不同部位的各向异性指数值及平均弥散系数值是不完全相同的，差异具有统计学意义（F值分别为720．365、96．413，均P〈0．001）。结论DTI可以评估24个月内正常婴幼儿的脑髓鞘发育状况，其中各向异性指数值及平均弥散系数值反映了不同部位、不同年龄段脑髓鞘化进程。Objective To explore the application value of magnetic resonance-diffusion tensor imaging （MR-DTI） in assessing myelination of normal infants. Methods Forty-eight full-term infants without central nervous system diseases and no abnormality found in magnetic resonance imaging （MRI） were divided into 6 groups according to age： group of 0-28 days （n = 6）, group of 29 days-3 months （n = 6）, group of 4-6 months （ n = 5 ）, group of 7-12 months （ n = 13 ）, group of 13-18 months （ n = 9） and group of 19-24 months （ n = 9）. They were examined with diffusion tensor imaging （DTI） to calculate the fractional anisotropy （FA） and average diffusion coefficient （ADC） values of different regions. Regions of interest（ROI） included peripheral white matter （bilateral frontal and parietal white matter, semioval center）, deep white matter （ anterior and posterior limb of internal capsule, genu and splenium of corpus callosum）, and deep gray matter （head of caudate nucleus, lentiform nucleus, and thalamus）. Then the changes of DTI parameters in the normal infants＇ myelination werc analyzed. Results Except the head of caudate nucleus and lentiform nucleus, the FA values in other brain regions had significant positive correlation with age （r value 〉 0.74, P 〈 0.001 ）. With the increasing of age, the FA values logarithmically increased. The ADC values in various ROI had significant negative correlation with age （all r 〈 - 0.74, P 〈 0. 001 ）, and they logarithmically decreased with age increasing. In addition, the FA and ADC values of different ages and various brain regions were not identical, and the differences were statistically significant （ F value was 720. 365 and 96. 413, respectively, both P 〈 0. 001 ）. Conclusion DTI is useful in evaluating the myelination of normal infants younger than 24 months. The FA and ADC values can reflect the process of myelination in various brain regions and age stages.

关 键 词：婴幼儿 磁共振成像 弥散张量成像 髓鞘发育 

分 类 号：R174[医药卫生—妇幼卫生保健] R445[医药卫生—公共卫生与预防医学]