新生儿和婴儿正常脑发育的MRI研究I．关于髓鞘形成

MRimagingstudyonnormalneonatalandinfantbrainmaturation(partI):myelinization

目的：通过本研究建立中国婴儿正常脑髓鞘化的时间表。材料与方法：选１００例２岁以内的没有神经系统疾病的小儿，按月龄分成５组，用０．３５ＴＭＲ仪在Ｔ１加权像（Ｔ１ＷＩ）和Ｔ２加权像（Ｔ２ＷＩ）上分别观察髓鞘形成的进程及在Ｔ２ＷＩ上对灰白质分辨进行分期。结果：（１）灰白质分辨分为５期，新生儿１００％属Ⅰ期，６个月内的婴儿８８％为Ⅱ期，６个月以上的婴儿２０％为Ⅲ期、８０％为Ⅳ期，１４个月时达Ⅴ期，１８个月时接近成人。（２）髓鞘化时间，后颅窝结构３～４个月时即达成人早期，内囊后肢在６个月内、前肢在７～１０个月，胼胝体压部是４个月、膝部是６个月，顶枕叶１０个月，额叶１２个月，颞叶１５～１８个月，皮层下的白质持续到２岁以后。结论：脑灰白质分辨的５期，反映了脑发育的过程，与月龄关系密切。

Purpose:Toestablishthechronologyofnormalbrainmyelinizationinneonatesandinfants.Materialsandmethods:Onehundredcasesfromnewbornto2yearsofagewithoutsignifi-cantneurologicsymptomswereselectedforstudy.Theyweredividedinto5agegroups.A0.35Tsu-perconductiveMRsystemwasused.TheMRimagingofthemyelinizationprocessandstagesofgrey-whitematerdiferentiationwereobservedonbothT1WI,andT2WIrespectively.Results:(1)Thegrey-whitematerdiferentiationwasdividedinto5stages.Innewbornperiod,itwasseentobestageⅠin100%;1～6monthsold,itwasstageⅡin88%;above6months,itwasstageⅢin20%,stageⅣin80%;14monthsandabove,stageⅤwaspredominant;itreachedtheadulttypeat18months.(2)Twentyareasinthebrainwereobservedformyelinizationprocess.Themyeliniza-tionofposteriorandanteriorlimbofinternalcapsule,thespleniumandgenu,thewhitematterintheparietal-occipitalarea,frontalareacouldbeseenat6,7～10,4,6,10,and12monthsoldrespective-ly.Myelinizationofthewhitematerinthetemporalareawasbeingthelastat15～18months.Myelinizationofthesubcorticalwhitematteraroundthetrigonalregioncontinuedafter2yearsofage.Conclusion:Thechronologyofmyelinizationandthestagesofgrey-whitematterdiferentiationwereincloserelationshipwiththeageoftheinfants.Theywereconsideredtobeofextremeimpor-tanceinevaluatingbrainmaturation.