In vivo measurement of T1ρ dispersion in the human brain at 1.5 tesla
In vivo measurement of T1ρ dispersion in the human brain at 1.5 tesla
复制标题
DOI：
10.1002/jmri.20016
复制
发表时间：
2004-04-01
影响因子：
4.4
通讯作者：
Reddy, R
中科院分区：
文献类型：
--
作者：
Borthakur, A;Wheaton, AJ;Reddy, R
目的：测定活体人脑T-1rho弛豫时间和TIP弥散度。材料与方法：采用标准GE头线圈，在1.5 t GE Signa临床扫描仪上进行磁共振成像（MRI）。采用基于快速自旋回波（FSE）的t -1rho加权MR脉冲序列获取5名健康男性志愿者的图像。在考虑研究目标和保证MR期间射频（RF）功率沉积不超过食品和药物管理局（FDA）规定的安全水平的同时，确定了最佳成像参数。结果：磁共振t -1rho加权图像显示不同脑组织间具有良好的对比。这些图像比相应的t -2加权图像模糊程度低，对比度相似，特别是在脑实质和脑脊液（CSF）之间的区域。在500 Hz的自旋锁定场下，白质（WM）、灰质（GM）和脑脊液的平均T-1rho值分别为85 +/- 3,99 +/- 1和637 +/- 78 msec。与相应的T-2值相比，实质T-1rho高30%，脑脊液T-1rho高78%。在自旋锁定频率0和500hz之间观察到T-1rho色散。结论：t -1rho加权MRI提供了极好的对比度和细节的大脑图像。在不同脑组织中测量的T-1rho值将作为分析与病理相关的T-1rho变化的有用基线值。
Purpose: To measure T-1rho relaxation times and TIP dispersion in the human brain in vivo.Materials and Methods: Magnetic resonance imaging (MRI) was performed on a 1.5-T GE Signa clinical scanner using the standard GE head coil. A fast spin-echo (FSE)-based T-1rho-weighted MR pulse sequence was employed to obtain images from five healthy male volunteers. Optimal imaging parameters were determined while considering both the objective of the study and the guarantee that radio-frequency (RF) power deposition during MR did not exceed Food and Drug Administration (FDA)-mandated safety levels.Results: T-1rho-weighted MR images showed excellent contrast between different brain tissues. These images were less blurred than corresponding T-2-weighted images obtained with similar contrast, especially in regions between brain parenchyma and cerebrospinal fluid (CSF). Average T-1rho values for white matter (WM), gray matter (GM), and CSF were 85 +/- 3, 99 +/- 1, and 637 +/- 78 msec, respectively, at a spin-locking field of 500 Hz. T-1rho is 30% higher in the parenchyma and 78% higher in CSF compared to the corresponding T-2 values. T-1rho dispersion was observed between spin-locking frequencies 0 and 500 Hz.Conclusion: T-1rho-weighted MRI provides images of the brain with superb contrast and detail. T-1rho values measured in the different brain tissues will serve as useful baseline values for analysis of T-1rho changes associated with pathology.