摘要
目的 :研究正常新生儿和婴儿脑髓鞘发育MRI表现。材料与方法 :选 12 0例 2岁以内 ,足月出生并且没有神经系统疾病的小儿 ,按月龄分成 5组 ,使用 0 15P磁共振成像系统 ,在T1加权像 (T1WI)和T2 加权像 (T2 WI)上分别观察髓鞘形成过程中的MRI信号变化以及观察各个月龄脑髓鞘化范围。结果 :(1)灰白质分辨分为 5期 ,Ⅰ期为新生儿期 ,脑白质在T1WI呈低信号 ,在T2 WI上呈高信号 ,灰质区在T1WI呈略高信号 ,在T2 WI上呈略低信号 ,灰白质对比清晰 ,Ⅱ期为 2～ 5个月 ,在T1WI上可见灰白质呈等信号 ,在T2 WI上灰白质信号表现与I期相同 ,Ⅲ期为 6～ 9个月 ,在T1WI上白质呈略高信号 ,在T2 WI上灰白质呈等信号。Ⅳ期为 10～ 18个月 ,此期灰白质信号反转 ,信号表现与I期相反 ,Ⅴ期为 19个月以上 ,灰白质信号接近成人。 (2 )脑髓鞘化规律 :从下到上 ,从中心到周围 ,从背侧到腹侧。结论 :脑灰白质分辨的 5期MRI表现 ,反映了脑髓鞘发育的过程 ,掌握各个月龄的MRI信号特点对判断脑发育是否落后十分重要。
Purpose:To analyze the MR features of normal brain maturation in neonates and infants.Materials and Methods:One hundred and twenty cases from newborn to 2 years of age without significant neurologic symptoms were selected for study.They were divided into 5 age groups.0 15T MR system was used.The MR imaging of myelinization process and stages of grey-white matter differentiation were observed on both T 1WI and T 2WI respectively.Results:(1)The grey-white matter differentiation was divided into 5 stages.In stage I,the signal intensities of grey matter were higher than white matter on T 1WI,and lower than that on T 2WI.The signal intensities of grey matter were equal to white matter on T 1WI in stage Ⅱand on T 2WI in stage Ⅲ.In stageⅣ,The signal intensities of them were contrary to that in stage I and reached the adult type in stage Ⅴ.(2)The myelinization process was from down to up,center to periphery,and dorsal part to facies ventralis.Conclusion:The chronology of myelinization,the stages of grey-white matter differentiation were in close relationship with the age of the infants.They were considered to be extreme importance in evaluation brain maturation.
出处
《现代医用影像学》
2000年第4期147-149,共3页
Modern Medical Imageology
关键词
脑髓鞘
婴儿
新生儿
磁共振成像
发育
Brain Myelin sheath Infant Newborn Megnetic Resonance Imaging
