Objective: To investigate the value of histogram parameters in quantifying brain development trajectory at slice of anterior and posterior horns of lateral ventricles on conventional brain MRI in normal children aged 0-5 years. Methods: Routine brain MRI data [apparent diffusion coefficient (ADC) map, T1-weighted imaging (T1WI), and T2-weighted imaging (T2WI)] were retrospectively collected from 300 children aged 0-5 years who underwent MRI at Children 's Hospital of Nanjing Medical University from April 2014 to November 2021, 154 males and 146 females, aged [M (Q1, Q3) ] 35.57(17.98,50.66)months. According to the random sampling method, they were divided into training set (n=240) and validation set (n=60) in a ratio of 8∶2. The training set was divided into 6 groups according to age:≤0.5 years, 24 persons; >0.5-≤1 years,21 persons; >1-≤2 years,31 persons; >2-≤3 years,44 persons; >3-≤4 years,42 persons; >4-≤5 years,78 persons. MRIcron software was used to delineate the whole brain at the level of the anterior and posterior horns of the lateral ventricles of the three MRI data as the region of interest. Then gray histograms and their parameters [including mean, maximum, minimum, skewness, kurtosis, mode, variance, and percentiles at 5% intervals from 10% to 95%(10th-95th) ]were obtained. Intra-class correlation coefficients (ICC) were used to assess consistency of intra-observer and inter-observer measurement. Representative parameters were selected by Spearman correlation analysis and curve fitting. The linear regression coefficient β represented development rates at different ages. The selected curve regression models were applied to the validation set, and the reliability of the model was evaluated with accuracy. Results: Intra-observer and inter-observer histogram measurement parameters were generally in good consistency (ICC>0.800, all P<0.001). Histogram parameters ADC 10th-65th, T1WI 55th-80th and T2WI 10th-45th were highly correlated with age (∣r∣≥0.700, 0.600 and 0.600 respectively; all P<0.001). ADC 30th and T2WI 10th had the greatest goodness of fit (R²=0.871, 0.873; both P<0.001). Map of brain development trends showed that ADC 30th and T2WI 10th decreased with age. ADC 30th changed rapidly before the age of 2 years, most significantly within 6 months, and the rate of decrease slowed down after 2 years old. T2WI 10th decreased rapidly within 1 year, and moderately after 1 year old. The curve regression models of ADC 30th and T2WI 10th had higher accuracy in validation set [93% (56/60) and 95% (57/60), respectively]. Conclusion: Histogram parameters can quantify brain developmental trajectories at slice of anterior and posterior horns of lateral ventricles on conventional MRI in normal children aged 0-5 years, and obtain the brain development curves reflecting this slice of this age group.
目的： 探讨基于直方图参数量化0~5岁正常儿童常规脑部MRI中侧脑室前后角层面脑发育轨迹的价值。 方法： 回顾性收集2014年4月至2021年11月在南京医科大学附属儿童医院接受MRI检查的300名0~5岁儿童的三种常规脑MRI数据［表观扩散系数（ADC）图、T1加权成像（T1WI）及T2加权成像（T2WI）］，男154名，女146名，年龄［M（Q1，Q3）］35.57（17.98，50.66）月。以8∶2的比例按照随机序列产生方法分成训练集240名及验证集60名。训练集按年龄分为6组：≤0.5岁组，24名；>0.5~≤1岁组，21名；>1~≤2岁组，31名；>2~≤3岁组，44名；>3~≤4岁组，42名；>4~≤5岁组，78名。用MRIcron软件勾画三种MRI数据中侧脑室前后角层面的全脑作为感兴趣区，获得灰度直方图及其参数［包括平均值、最大值、最小值、偏度、峰度、众数、方差及10%~95%每间隔5%的百分位数（10th~95th）］。采用组内相关系数（ICC）评价观察者内部及观察者间测量一致性。通过Spearman相关分析及曲线拟合筛选出代表性参数。线性回归系数β表示不同年龄段发育速度。将筛选出的曲线回归模型应用于验证集，用准确率评价模型的可靠性。 结果： 观察者内部及观察者间直方图参数整体一致性好（ICC>0.800，均P<0.001）。直方图参数ADC 10th~65th，T1WI 55th~80th及T2WI 10th~45th与年龄相关性较高（∣r∣分别≥0.700、0.600、0.600，均P<0.001）。ADC 30th及T2WI 10th的拟合优度（R²=0.871、0.873，均P<0.001）最大。脑发育趋势图显示ADC 30th及T2WI 10th随年龄增长而下降，ADC 30th在2岁前变化较快，以6个月内下降最为明显，2岁后下降速度变缓；T2WI 10th在1岁内快速减低，1岁后速度趋缓。ADC 30th与T2WI 10th的曲线回归模型在验证集中具有较高的准确率［分别为93%（56/60）、95%（57/60）］。 结论： 直方图参数可以量化0~5岁正常儿童常规脑部MRI中侧脑室前后角层面的脑发育轨迹，并获得反映该年龄段该层面的脑发育生长曲线。.