Human brain-structure resolved T2 relaxation times of proton metabolites at 3 Tesla
Human brain-structure resolved T2 relaxation times of proton metabolites at 3 Tesla
复制标题
DOI：
10.1002/mrm.21250
复制
发表时间：
2007-06-01
影响因子：
3.3
通讯作者：
Gonen, Oded
中科院分区：
文献类型：
--
作者：
Zaaraoui, Wafaa;Fleysher, Lazar;Gonen, Oded
本文报道了8名健康志愿者在3 T条件下N-乙酰天冬氨酸（NAA）、总胆碱（Cho）和肌酸（Cr）在几个脑区的横向弛豫时间T ~ 2。它们是在320个体素中以1 cm（3）空间分辨率同时获得的三维（3D）质子MR波谱（H-1-MRS）。使用两点协议，通过调整每个点处的回波延迟（TEi）和平均数Ni来优化每个给定时间的最小误差。8名健康受试者（4名男性和4名女性，年龄= 26 +/- 2岁）接受了4次15分钟的3D采集（TE 1 = 35 ms，N-1 = 1; TE 2 = 285 ms，N-2 = 3）的小时程序。结果显示，在所有受试者中，灰质（GM）结构中的NAA和Cr T（2）s（分别为226 +/- 17和137 +/- 12 ms）比相应的白色物质中的T（2）s（WM;分别为264 +/- 10和155 +/- 7 ms）短13-17%。GM和WM之间Cho的T（2）s没有差异（分别为207 +/- 17和202 +/- 8）。出于代谢定量的目的，这些值证明1）整个大脑和2）所有受试者之前每种代谢物使用1个T2的合理性在+/- 10%范围内。这些T-2值（据我们所知，这是在该领域首次获得的，空间分辨率，覆盖范围和精度）对于可靠的绝对代谢定量是必不可少的。
The transverse relaxation times, T-2, of N-acetylaspartate (NAA), total choline (Cho), and creatine (Cr) obtained at 3T in several human brain regions of eight healthy volunteers are reported. They were obtained simultaneously in 320 voxels with three-dimensional (3D) proton MR spectroscopy (H-1-MRS) at 1 cm(3) spatial resolution. A two-point protocol, optimized for the least error per given time by adjusting both the echo delay (TEi) and number of averages, Ni, at each point, was used. Eight healthy subjects (four males and four females, age = 26 +/- 2 years) underwent the hour-long procedure of four 15-min, 3D acquisitions (TE1 = 35 ms, N-1 = 1; and TE2 = 285 ms, N-2 = 3). The results reveal that across all subjects the NAA and Cr T(2)s in gray matter (GM) structures (226 +/- 17 and 137 +/- 12 ms, respectively) were 13-17% shorter than the corresponding T(2)s in white matter (WM; 264 +/- 10 and 155 +/- 7 ms, respectively). The T(2)s of Cho did not differ between GM and WM (207 +/- 17 and 202 +/- 8, respectively). For the purpose of metabolic quantification, these values justify to within +/- 10% the previous use of one T2 per metabolite for 1) the entire brain and 2) all subjects. These T-2 values (which to our knowledge were obtained for the first time at this field, spatial resolution, coverage, and precision) are essential for reliable absolute metabolic quantification.