R2值评价健康成年人脑铁含量与年龄的相关性研究

R2*values in estimation of age-related iron deposition in brain of healthy adults

目的采用3.0T增强梯度回波T2^＊加权血管成像（ESWAN）定量测量健康成年人额叶白质区及灰质核团的R2^＊值,探讨额叶白质区及灰质核团与年龄的相关性。方法收集20～85岁的157例健康成年人进行MRI常规及磁敏感加权成像（SWI）扫描,按其年龄段分为6组：A组20～29岁,B组30～39岁,C组40～49岁,D组50～59岁,E组60～69岁,F组≥70岁。经后处理在R2^＊图像上分别测量双侧额叶白质区、红核、黑质网状带、黑质致密带、尾状核头、壳核、苍白球和丘脑的R2^＊值,分析R2^＊值与年龄的相关性。结果健康成年人在黑质网状带、苍白球的R2^＊值最低,额叶白质区的R2^＊值最高。其中黑质网状带、壳核、苍白球、丘脑和尾状核头的R2^＊值在部分年龄段比较,差异有统计学意义（P〈0.05）,有一定规律性。而红核、黑质致密带、额叶白质区的R2^＊值在不同年龄段比较,差异无统计学意义（P〉0.05）。红核、黑质网状部、壳核、苍白球、尾状核头的R2^＊值与年龄呈正相关（r=0.188、0.269、0.524、0.347和0.407,P〈0.05）,丘脑的R2^＊值与年龄呈负相关（r=-0.317,P=0.000）,而黑质致密部、额叶白质区的R2^＊值与年龄无关（P〉0.05）。结论 SWI能清晰显示脑内核团的结构,准确评估脑内的铁含量和随年龄变化的规律。

Objective To quantitatively analyze the iron deposition in deep brain gray nuclei and frontal white matter in healthy population and its correlation with age using enhanced gradient echo T2star-weighted angiography（ESWAN） with 3.0 Tesla scanner. Methods Totally 157 healthy subjects（ranging 20-85 years）were scanned with routine sequences and ESWAN sequences. The subjects were divided into 6 groups according to their age： group A（age 20-29 years）, group B（age 30-31 years）, group C（age 40-49 years）,group D（age 50-59 years）, group E（age 60-69 years） and group F（age 〉70 years）. R2^＊value was measured in both sides of frontal white matter, red nucleus, substantia nigra pars reticulate, substantia nigra pars compacta, putamen, globus pallidus, head of caudate nucleus and thalamus; and the correlations between the R2^＊ values and age were analyzed. Results The R2^＊values of globus pallidus and substantia nigra pars reticulate were the lowest. The highest R2^＊value was seen in the frontal white matter. The differences of R2^＊values among some age groups had statistical significance in substantia nigra pars reticulate, putamen, globus pallidus, thalamus and head of caudate nucleus（P〈0.05）. Obvious correlations between age and R2^＊ value were shown in substantia nigra pars reticulate（r = 0.269）, putamen（r = 0.524）, globus pallidus（r = 0.347）, head of caudate nucleus（r = 0.407）, and thalamus（r =-0.317）, while a weak correlation was displayed in red nucleus（r = 0.188）. Conclusions ESWAN can clearly display the cerebral nuclei, accurately evaluate the brain iron content and age-related iron concentration changes.