Mascalchi Mario, Toschi Nicola, Ginestroni Andrea, Giannelli Marco, Nicolai Emanuele, Aiello Marco, Soricelli Andrea, Diciotti Stefano
Quantitative and Functional Neuroradiology Program at Meyer Children's Hospital and Careggi Hospital of Florence, Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy.
J Magn Reson Imaging. 2014 Aug;40(2):360-6. doi: 10.1002/jmri.24355. Epub 2013 Oct 29.
To explore gender, age-related, and regional differences of magnetization transfer ratio (MTR) of brain cortical and subcortical gray matter (GM).
In all, 102 healthy subjects (51 women and 51 men; range 25-84 years) were examined with 3-mm thick MT images. We assessed MTR in automatically segmented GM structures including frontal, parietal-insular, temporal, and occipital cortex, caudate, pallidus and putamen, and cerebellar cortex. A general linear model analysis was conducted to ascertain the linear and quadratic relationship among the MTR and gender, age, and anatomical structure.
The effect of gender was borderline (P = 0.07) in all GM structures (with higher MTR values in men), whereas age showed a significant linear as well as quadratic effect in all cortical and subcortical GM structures (P ≤ 0.001). Quadratic age-related decrease in MTR began at about 40 years of age. Mean and standard deviation (SD) of MTR had the following decreasing order: thalamus (58.3 + 0.8), pallidus (56.8 ± 1.3), caudate (55.5 ± 1.6) and putamen (54.6 ± 1.1); temporal (56.8 ± 0.9), parietal-insular (56.8 ± 1.1), frontal (56.5 ± 1.1), occipital (55.4 ± 1.0) and cerebellar (53.2 ± 1.0) cortex. In post-hoc testing, all regional pairwise differences were statistically significant except pallidus vs. temporal or parietal-insular cortex, caudate vs. occipital cortex, frontal vs. parietal-insular or temporal cortex.
MTR of the cortical and subcortical brain GM structures decreases quadratically after midlife and shows significant regional differences.
探讨脑皮质及皮质下灰质（GM）的磁化传递率（MTR）的性别、年龄及区域差异。
共对102名健康受试者（51名女性和51名男性；年龄范围25 - 84岁）进行了3毫米厚的MT图像检查。我们评估了自动分割的GM结构中的MTR，包括额叶、顶叶 - 岛叶、颞叶和枕叶皮质、尾状核、苍白球和壳核以及小脑皮质。进行了一般线性模型分析，以确定MTR与性别、年龄和解剖结构之间的线性和二次关系。
在所有GM结构中，性别影响处于临界状态（P = 0.07）（男性的MTR值较高），而年龄在所有皮质和皮质下GM结构中显示出显著的线性及二次效应（P≤0.001）。与年龄相关的MTR二次下降始于约40岁。MTR的均值和标准差（SD）具有以下递减顺序：丘脑（58.3 + 0.8）、苍白球（56.8±1.3）、尾状核（55.5±1.6）和壳核（54.6±1.1）；颞叶（56.8±0.9）、顶叶 - 岛叶（56.8±1.1）、额叶（56.5±1.1）、枕叶（55.4±1.0）和小脑（53.2±1.0）皮质。在事后检验中，除苍白球与颞叶或顶叶 - 岛叶皮质、尾状核与枕叶皮质、额叶与顶叶 - 岛叶或颞叶皮质外，所有区域的两两差异均具有统计学意义。
脑皮质和皮质下GM结构的MTR在中年后呈二次下降，并显示出显著的区域差异。
