Li Yáo T, Huang Hua, Zhuo Zhizheng, Lu Pu-Xuan, Chen Weitian, Wáng Yì Xiáng J
Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR.
Department of Radiology, Shenzhen No. 3 People's Hospital, Shenzhen, Guangdong Province, China.
Magn Reson Imaging. 2017 Jun;39:200-205. doi: 10.1016/j.mri.2017.03.005. Epub 2017 Mar 18.
To investigate normative value and age-related change of brain magnetic resonance T1ρ relaxation at 1.5T.
This study was approved by the local ethical committee with participants' written consent obtained. There were 42 adults healthy volunteers, including 20 males (age: 41±16 (mean±standard deviation) years, range: 22-68years,) and 22 females (age: 39±15years, range: 21-62years). MRI was performed at 1.5T using 3D fluid suppressed turbo spin echo sequence. Regions-of-interests (ROIs) were obtained by atlas-based tissue segmentation and T1ρ was calculated by fitting the mean value to mono-exponential model. Correlation between T1ρ relaxation of brain gray matter regions and age was investigated.
A regional difference among individual gray matter areas was noted; the highest values were observed in the hippocampus (98.37±5.37ms, median: 97.88ms) and amygdala (94.95±4.34ms, median: 94.73ms), while the lowest values were observed in the pallidum (83.81±5.49ms, median: 83.77ms) and putamen (83.93±4.76ms, median: 83.99ms). Gray matter T1ρ values decreased slowly (mean slope: -0.256) and significantly (p<0.05) with age in gray matter for subjects younger than 40years old, while for subjects older than 40years old there was no apparent correlation between T1ρ relaxation and age. Global white matter measured T1ρ value of 88.65±3.47ms (median: 87.86ms), and the correlation with age was not significant (p=0.18).
Gray matter T1ρ relaxation demonstrates a bi-phase change with age in adults of 22-68years.
研究1.5T条件下脑磁共振T1ρ弛豫的正常参考值及与年龄相关的变化。
本研究经当地伦理委员会批准，并获得参与者的书面同意。共有42名健康成年志愿者，其中男性20名（年龄：41±16（均值±标准差）岁，范围：22 - 68岁），女性22名（年龄：39±15岁，范围：21 - 62岁）。采用1.5T磁共振成像，使用3D液体抑制快速自旋回波序列。通过基于图谱的组织分割获取感兴趣区域（ROI），并通过将平均值拟合到单指数模型来计算T1ρ。研究脑灰质区域T1ρ弛豫与年龄之间的相关性。
观察到各灰质区域之间存在差异；海马体（98.37±5.37ms，中位数：97.88ms）和杏仁核（94.95±4.34ms，中位数：94.73ms）的值最高，而苍白球（83.81±5.49ms，中位数：83.77ms）和壳核（83.93±4.76ms，中位数：83.99ms）的值最低。40岁以下受试者灰质T1ρ值随年龄缓慢下降（平均斜率：-0.256）且具有显著相关性（p<0.05），而40岁以上受试者T1ρ弛豫与年龄之间无明显相关性。全脑白质测量的T1ρ值为88.65±3.47ms（中位数：87.86ms），与年龄的相关性不显著（p = 0.18）。
22 - 68岁成年人的灰质T1ρ弛豫随年龄呈现双相变化。
