R2?鄢值评价健康成年人脑铁含量与年龄的相关性研究

目的  采用3.0T增强梯度回波T2?鄢加权血管成像（ESWAN）定量测量健康成年人额叶白质区及灰质核团的R2?鄢值，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?鄢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?鄢值，分析R2?鄢值与年龄的相关性。结果  健康成年人在黑质网状带、苍白球的R2?鄢值最低，额叶白质区的R2?鄢值最高。其中黑质网状带、壳核、苍白球、丘脑和尾状核头的R2?鄢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?鄢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?鄢值与年龄呈正相关（r =0.188、0.269、0.524、0.347和0.407，P <0.05），丘脑的R2?鄢值与年龄呈负相关（r =-0.317，P =0.000），而黑质致密部、额叶白质区的R2?鄢值与年龄无关（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。

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

 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 T2 star-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.