0~2岁婴幼儿磁共振脑白质模板的建立及验证

Investigation and validation of magnetic resonance white matter atlas for 0 to 2 years old infants

目的:研究0~2岁中国正常婴幼儿大脑白质微结构发育演变过程的磁共振弥散张量特征,建立婴幼儿脑白质微结构标准模板并进行验证。方法:应用非线性高配准精度的微分同胚非刚性配准范式(large deformation diffeomorphic metric mapping,LDDMM)对核磁弥散张量图像进行配准,选取经神经内科医师、影像科医师及Gesell发育诊断量表(Gesell developmental scale,GDS)评估临床查体、运动和认知均正常,常规核磁头颅检查未见颅内占位及先天畸形,足月顺产,无母体孕期疾病(妊高症、糖尿病等)、宫内缺血缺氧、头颅外伤、颅内感染、颅内手术病史、精神疾患家族史的0~2岁婴幼儿共120例进行头颅扩散张量成像(diffusion tension imaging,DTI)扫描,按照婴幼儿年龄将数据分为6组(A组:1 d~1.5个月,B组:1.5~4.5个月,C组:4.5~9.0个月,D组:9~15个月,E组:15~21个月,F组:21~24个月),以每组选定的独立样本为模板,应用MRlcron、DtiStudio、DiffeoMap及SPM软件结合LDDMM配准算法对所得DTI数据进行数据预处理、张量计算和图像归一化,并应用Matlab对最终图像进行平均计算构建相应组别对应的平均图谱。建立图谱包括各向异性(fractional anisotropy,FA)图、彩色编码图、T1加权像图(T1 weighted image,T1WI)、b0图以及平均弥散加权图(mean of diffusion weighted figures,DWfs)。结果:建立0~2岁中国婴幼儿磁共振正常大脑白质FA、T1WI、b0、DWfs以及彩色编码模板,所有模板主观评分均超过2分,客观评估参量模板均方根误差(root mean squared error,RMSE)控制在0.19以下,且根据结构T1模板建立的月龄0~2岁儿童大脑平均体积变化立方趋势图与既往文献报道结构模板变化趋势相同。结论:应用非线性高配准精度的微分同胚非刚性配准范式建立的0~2岁中国正常婴幼儿大脑白质微结构发育演变模板,不仅为进一步分析人类大脑发育及功能形成过程、脑发育相关疾病的机制和治疗效果提供基础数据,而且为医疗、教学、科研提供客观的影像学信息。

Objective:To construct and verify a standard template of white matter based on Chinese normal 0 to 2 years old infants by using nonlinear high registration accuracy of non-rigid diffeomorphism paradigm(large deformation diffeomorphic metric mapping,LDDMM).Methods:Full-term spontaneous labor children without maternal pregnancy disease(hypertension,diabetes,etc.),intrauterine hypoxia and ischemia,head trauma,intracranial infection,intracranial surgery history,family history of mental disorders were selected.Diffusion tensor imaging(DTI)data from the 120 normal Chinese infants under 2 years old were acquired after excluding the existence of neurological diseases revealed by neurologists,radiologists and Gesell Developmental Scale.All the data were divided into six groups including group A:1 day to 1.5 months,group B:1.5 to 4.5 months,group C:4.5 to 9.0 months,group D:9 to 15 months,group E:15 to 21 months,and group F:21 to 24 months.Data pre-processing,normalizing,tensor fitting and calculation of all the images were performed by using MRlcron,DtiStudio,DiffeoMap and SPM software package combined with LDDMM image registration method based on the selected single template of each group.And the average templates of each group were constructed by MATLAB software platform.The set of templates included fractional anisotropy figure(FA),color map,T1 weighted image,b0 image and the mean of all DWfs figures.Results:The templates of FA,T1,b0,DWfs and color map for the normal brain magnetic resonance white matter development of the Chinese infants aged 0 to 2 years were successfully established with the subjective scores exceeding 2 points.The objective evaluation root mean squared error was controlled below 0.19,and the cubic chart of brain alternation trend for the children aged 0 to 2 years was consistent with previous literature.Conclusion:Constructing a standard template of white matter based on Chinese normal infants,by using nonlinear high registration accuracy of non-rigid diffeomorphism paradigm provides not only a foundation of further research on brain development,mechanism and treatment of pediatric diseases associated with brain,but also objective and fair imaging information for medical education and research.