Department of Neurobiology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, Los Angeles, California 90095-1763, USA.
J Magn Reson Imaging. 2012 Feb;35(2):300-8. doi: 10.1002/jmri.22831. Epub 2011 Oct 10.
To determine normal T2-relaxation values from different brain areas in healthy adults, assess age-related T2-relaxation changes in those sites, and evaluate potential gender-related T2-relaxation value differences.
We performed proton-density and T2-weighted imaging in 60 healthy adults (male: 38, age range = 31-64 years, mean age ± SD = 46.1 ± 9.3 years; female: 22, age range = 37-66 years, mean age ± SD = 49.5 ± 8.3 years), using a 3.0 Tesla MRI scanner. T2-relaxation values were calculated voxel-by-voxel from proton-density and T2-weighted images, and whole-brain T2-relaxation maps were constructed and normalized to a common space. A set of regions-of-interest were outlined within the basal ganglia, limbic, frontal, parietal, temporal, occipital, thalamic, hypothalamic, cerebellar, and pontine regions using mean background images derived from normalized and averaged T2-weighted images of all individuals, and regional T2-relaxation values were determined from these regions-of-interest and normalized T2-relaxation maps. Pearson's correlations were calculated between T2-relaxation values and age, and male-female differences evaluated with independent-samples t-tests.
T2-relaxation values typically increased with age in multiple brain sites; only a few regions showed declines, including the putamen and ventral pons. Sex-related differences in T2-relaxation values appeared in basal ganglia, frontal, temporal, occipital, and cerebellar regions; males showed higher values over females in these sites.
Establishment of normative adult T2-relaxation values over different brain areas, with age and sex as co-factors, offers baseline values against which disease-related tissue changes can be assessed.
确定健康成年人不同脑区的正常 T2 弛豫值，评估这些部位的年龄相关 T2 弛豫变化，并评估潜在的性别相关 T2 弛豫值差异。
我们使用 3.0T MRI 扫描仪对 60 名健康成年人（男性：38 名，年龄范围 31-64 岁，平均年龄 ± 标准差=46.1 ± 9.3 岁；女性：22 名，年龄范围 37-66 岁，平均年龄 ± 标准差=49.5 ± 8.3 岁）进行了质子密度和 T2 加权成像。从质子密度和 T2 加权图像中逐像素计算 T2 弛豫值，并构建全脑 T2 弛豫图并归一化为公共空间。使用从所有个体归一化和平均 T2 加权图像得出的平均背景图像，在基底节、边缘系统、额叶、顶叶、颞叶、枕叶、丘脑、下丘脑、小脑和脑桥区域内勾画了一组感兴趣区，并从这些感兴趣区和归一化 T2 弛豫图中确定了区域 T2 弛豫值。计算了 T2 弛豫值与年龄之间的 Pearson 相关系数，并使用独立样本 t 检验评估了男性和女性之间的差异。
T2 弛豫值通常在多个脑区随年龄增加而增加；只有少数区域显示下降，包括壳核和腹侧脑桥。T2 弛豫值存在性别差异，见于基底节、额叶、颞叶、枕叶和小脑区域；这些部位男性的 T2 弛豫值高于女性。
建立不同脑区的成人 T2 弛豫值的正常值，并将年龄和性别作为协变量，提供了可用于评估疾病相关组织变化的基线值。
