应用踝关节MRI T1WI推断活体年龄

目的分析踝关节MRI T1加权图像中胫骨、腓骨远端及跟骨骨骺发育特点,为踝关节MRI成像是否有助于青少年14、16及18岁年龄推断提供明确的答案。方法收集1025例8-25岁的汉族青少年踝关节MRI T1加权图像,探索年龄与分期之间的相关性,分析各期年龄分布的性别差异,并建立推断个体是否年满14、16及18岁的Logistic回归方程。结果年龄与胫骨、腓骨远端及跟骨骨骺分期呈正相关。胫骨、腓骨远端骨骺完全闭合的最小年龄为男性14岁,女性13岁;跟骨骨骺完全闭合的最小年龄为男性14岁,女性11岁。除胫骨、腓骨3期,各期年龄分布性别差异有统计学意义。判断个体是否年满14、16及18岁的方程的推断准确率分别为:男性97.52%,90.08%,82.64%;女性97.59%,97.59%,87.95%。结论踝关节MRI T1加权图像在法医鉴定的活体年龄推断中具有重要的意义。

Age estimation based on T1-weighted MRI of ankle joint

Objective To explore the value of MRI of the ankle joint in inferring whether the subject is over 14, 16 or 18 years of age by analyzing the characteristics of the distal tibial, distal fibular and the calcaneal epiphysis on T1-weighted imaging(T1 WI). Methods MRI T1 WI of 1025 ankle joints of persons aged 8-25 years were collected, the correlation between stage and age was analyzed by spearman rank correlation analysis, the difference of sex was tested, and the Logistic regression equations to infer whether the unknown person is over 14, 16 or 18 years old were built. Results There were positive correlations between ages and stages of distal tibial, distal fibular and calcaneal epiphysis. The complete fusions of distal tibial and fibular epiphysis were firstly occurred at the age of 14 years in males and 13 years in females. The complete fusion of calcaneal epiphysis was firstly occurred at the age of 14 years in males and 11 years in females. With the exception of distal tibial and fibular stage 3, the significant sex differences were found in the remaining stages. The accuracy rates based on Logistic regression equations in estimating whether the unknown individuals were over 14, 16 or 18 years of age were 97.52%, 90.08%, 82.64% in males and 97.59%, 97.59%, 87.95% in females. Conclusion MRI T1 WI of ankle joint is important in forensic age estimation.