Regional specificity of MRI contrast parameter changes in normal ageing revealed by voxel-based quantification (VBQ).
Regional specificity of MRI contrast parameter changes in normal ageing revealed by voxel-based quantification (VBQ).
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DOI：
10.1016/j.neuroimage.2011.01.052
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发表时间：
2011-04-15
期刊：
影响因子：
5.7
通讯作者：
Weiskopf, N.
中科院分区：
文献类型：
--
作者：
Draganski, B.;Ashburner, J.;Hutton, C.;Kherif, F.;Frackowiak, R. S. J.;Helms, G.;Weiskopf, N.
关键词：
正常的衰老与大脑微观结构的特征变化有关。尽管体内神经成像在宏观尺度上捕获了与年龄相关的解剖学变化的时空模式，但我们对细胞和分子水平上潜在（病理）生理过程的了解仍然有限。本研究的目的是利用定量磁共振成像（MRI）以及常规形态学评估来探索正常衰老中的脑组织特性。采用全脑方法，对26名年龄在18-85岁的成年人进行了扩散张量、磁化传递（MT）、R1和R2*松弛参数的体素形态学分析（VBM）和体素量化（VBQ）。我们发现皮层和皮层下灰质体积与年龄相关的减少与分数各向异性（FA）、平均扩散率（MD）、MT和R2*的变化是平行的。后者是区域特异性取决于他们对显微组织特性的不同敏感性。脑白质的VBQ显示出明显的年龄相关微结构变化的解剖模式。MT的广泛而深刻的减少与局部FA的减少形成对比，并与MD的增加并行。在重叠的枕顶白质区域，R1降低和R2*增加的程度较小。我们基于当前的生物物理模型，将我们的发现解释为年龄依赖性脑萎缩和髓鞘、铁沉积和水的潜在微结构变化的指纹。我们提出的VBQ方法允许对成像参数之间的相互作用进行系统的无偏探索，并扩展了当前检测大脑神经退行性过程的方法。所证明的参数特异性分布模式提供了对体内与年龄相关的大脑结构变化的见解，并为在健康老龄化背景下研究疾病提供了必要的基线数据。►基于flash的高分辨率参数映射适用于临床用途。年龄相关的参数变化模式反映了组织特性的特异性。►结合VBM和VBQ提供了关于大脑结构的补充信息。
Normal ageing is associated with characteristic changes in brain microstructure. Although in vivo neuroimaging captures spatial and temporal patterns of age-related changes of anatomy at the macroscopic scale, our knowledge of the underlying (patho)physiological processes at cellular and molecular levels is still limited. The aim of this study is to explore brain tissue properties in normal ageing using quantitative magnetic resonance imaging (MRI) alongside conventional morphological assessment. Using a whole-brain approach in a cohort of 26 adults, aged 18–85 years, we performed voxel-based morphometric (VBM) analysis and voxel-based quantification (VBQ) of diffusion tensor, magnetization transfer (MT), R1, and R2* relaxation parameters. We found age-related reductions in cortical and subcortical grey matter volume paralleled by changes in fractional anisotropy (FA), mean diffusivity (MD), MT and R2*. The latter were regionally specific depending on their differential sensitivity to microscopic tissue properties. VBQ of white matter revealed distinct anatomical patterns of age-related change in microstructure. Widespread and profound reduction in MT contrasted with local FA decreases paralleled by MD increases. R1 reductions and R2* increases were observed to a smaller extent in overlapping occipito-parietal white matter regions. We interpret our findings, based on current biophysical models, as a fingerprint of age-dependent brain atrophy and underlying microstructural changes in myelin, iron deposits and water. The VBQ approach we present allows for systematic unbiased exploration of the interaction between imaging parameters and extends current methods for detection of neurodegenerative processes in the brain. The demonstrated parameter-specific distribution patterns offer insights into age-related brain structure changes in vivo and provide essential baseline data for studying disease against a background of healthy ageing. ►High-resolution FLASH-based parameter mapping is suitable for clinical purposes. ►Patterns of age-dependent parameter changes reflect specificity to tissue properties. ►Combining VBM and VBQ offers complementary information about brain architecture.
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影响因子：
3.3
作者：
Bjarnason, TA;Vavasour, IM;MacKay, AL
通讯作者：
MacKay, AL
影响因子：
5.7
作者：
Barrick, Thomas R.;Charlton, Rebecca A.;Markus, Hugh S.
通讯作者：
Markus, Hugh S.
影响因子：
14.5
作者：
Fazekas, F;Ropele, S;Schmidt, R
通讯作者：
Schmidt, R
影响因子：
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作者：
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通讯作者：
Cummings, JL
DOI：
10.1073/pnas.0610821104
发表时间：
2007-07-10
影响因子：
11.1
作者：
Duyn, Jeff H.;van Gelderen, Peter;Fukunaga, Masaki
通讯作者：
Fukunaga, Masaki