山西省青少年锁骨胸骨端骨龄推断数学模型的构建

Establishment of Mathematical Models for Skeletal Age Determination of Extremi⁃tas Sternalis of Clavicle in Shanxi Adolescents

目的基于我国山西省青少年锁骨胸骨端骨骺发育情况与年龄的相关性,利用多元统计方法建立骨龄推断的数学模型。方法利用薄层计算机体层扫描技术对山西省562例胸锁关节样本(454例建模,108例外部验证)进行扫描,获取容积再现后采集双侧锁骨胸骨端骨骺面积、干骺端面积、锁骨胸骨端骨骺最长径、干骺端最长径,并分别计算双侧骨骺面积与干骺端面积之比、骨骺最长径与干骺端最长径之比等指标,再利用多元回归及随机森林判别构建青少年活体年龄推断的数学模型。结果观察指标与年龄均具有较强的相关性(r>0.85)。基于双侧骨骺最长径与干骺端最长径之比、骨骺面积与干骺端面积之比建立的男女性多元线性回归数学模型(4个指标全部进入模型)内部验证准确率(±1.0岁)均在92%以上,108例外部验证准确率(±1.0岁)均大于70%。随机森林判别模型对18.0周岁以上(≥18.0周岁)以及未满18.0周岁的袋外数据错误率均低于2%,108例外部验证结果的准确率也均大于80%。结论本研究构建的回归及判别模型具有一定的可靠性及准确性,可用于山西省青少年活体年龄推断。

Objective To develop mathematical models for skeletal age determination with multiple statistic method based on the correlation between age and the growth of the epiphysis of extremitas sternalis of clavicle in Shanxi adolescents.Methods The 562 Shanxi sternoclavicular joint samples(454 cases of modelling,108 cases of external verification)were scanned by the thin-section computed tomography.After volume rendering was obtained,indicators such as area of epiphysis,area of metaphysis,longest diameter of epiphysis and longest diameter of metaphysis of both extremitas sternalis of clavicle were collected.Indicators such as the ratio of area of epiphysis to area of metaphysis,and the ratio of longest diameter of epiphysis to longest diameter of metaphysis of both sides were calculated.Then multiple linear regression and random forest discriminant models were used to build mathematical models for age determination of adolescents.Results The obtained indicators exhibited a strong correlation with age(r>0.85).The multiple linear regression model for males and females(all 4 indicators entering the model)based on the ratio of longest diameter of epiphysis to longest diameter of metaphysis and the ratio of area of epiphysis to area of metaphysis had an internal validation accuracy rate(±1.0 year)of over 92%and 108 cases had an external validation accuracy rate of over 70%(±1.0 year).The out of bag error rates of random forest discriminant models were less than 2%for people over 18.0 years old(≥18.0 years old)and under 18.0 years old.The external validation accuracy rates of the 108 cases were over 80%.Conclusion The regression and discriminant models established in this study have certain reliability and accuracy and can be used in age determination of Shanxi adolescents.