Department of Biomedical Engineering, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada.
Hum Brain Mapp. 2021 Oct 1;42(14):4597-4610. doi: 10.1002/hbm.25569. Epub 2021 Jun 29.
Putative MRI markers of iron in deep gray matter have demonstrated age related changes during discrete periods of healthy childhood or adulthood, but few studies have included subjects across the lifespan. This study reports both transverse relaxation rate (R2*) and quantitative susceptibility mapping (QSM) of four primary deep gray matter regions (thalamus, putamen, caudate, and globus pallidus) in 498 healthy individuals aged 5-90 years. In the caudate, putamen, and globus pallidus, increases of QSM and R2* were steepest during childhood continuing gradually throughout adulthood, except caudate susceptibility which reached a plateau in the late 30s. The thalamus had a unique profile with steeper changes of R2* (reflecting additive effects of myelin and iron) than QSM during childhood, both reaching a plateau in the mid-30s to early 40s and decreasing thereafter. There were no hemispheric or sex differences for any region. Notably, both R2* and QSM values showed more inter-subject variability with increasing age from 5 to 90 years, potentially reflecting a common starting point in iron/myelination during childhood that diverges as a result of lifestyle and genetic factors that accumulate with age.
在健康儿童或成年的特定时期，深部灰质铁的推测性 MRI 标志物已显示出与年龄相关的变化，但很少有研究包括整个生命周期的受试者。本研究报告了 498 名年龄在 5 至 90 岁的健康个体的四个主要深部灰质区域（丘脑、壳核、尾状核和苍白球）的横向弛豫率（R2*）和定量磁化率映射（QSM）。在尾状核、壳核和苍白球中，QSM 和 R2* 的增加在儿童期最为陡峭，一直持续到成年期，除了尾状核磁化率在 30 多岁后期达到平台期。丘脑具有独特的特征，在儿童期 R2*（反映髓鞘和铁的附加效应）的变化比 QSM 更为陡峭，两者在 30 多岁中期至 40 岁早期达到平台期，此后逐渐下降。任何区域均无半球或性别差异。值得注意的是，R2*和 QSM 值的个体间差异随着年龄从 5 岁到 90 岁的增加而增加，这可能反映了儿童时期铁/髓鞘化的共同起点，由于生活方式和遗传因素随着年龄的增长而积累，导致这种起点发生分歧。
