Mlynárik V, Gruber S, Moser E
NMR Group, Institute of Medical Physics, University of Vienna, A-1090 Vienna, Austria.
NMR Biomed. 2001 Aug;14(5):325-31. doi: 10.1002/nbm.713.
Longitudinal and transverse relaxation times were measured for proton MRS signals from human brain metabolites at 3 T using a short-echo STEAM protocol and a surface coil as a transmitter/receiver. Volumes of interest containing mostly grey or mostly white matter were selected in occipital lobes of healthy subjects and relaxation times for the following resonances were obtained: N-acetylaspartate at 2.01 ppm (T(1) and T(2)), glutamate at 2.35 ppm (T(1)), creatine at 3.03 and 3.92 ppm (T(1) and T(2)), choline-containing substances at 3.22 ppm (T(1) and T(2)), myo-inositol at 3.57 and 3.65 ppm (T(1)) and the overlapping signals of glutamate and glutamine at 3.75 ppm (T(1)). The T(1) relaxation times obtained range from 0.97 to 1.47 s for grey matter and from 0.87 to 1.35 s for white matter. On the other hand, T(2) relaxation times range from 116 to 247 ms and from 141 to 295 ms in grey and white matter, respectively. Generally, the T(1) values measured at 3 T are close to the previously published data found at 1.5, 2 and 4.1 T. Also, the T(2) values confirm the previously observed decrease in transverse relaxation times with increasing static magnetic field. The proton relaxation times obtained will allow improved sequence design and spectra quantitation at 3 T, currently tested for enhanced clinical applications.
使用短回波时间的激励回波采集模式（STEAM）和作为发射/接收装置的表面线圈，在3T磁场下测量了人脑代谢物质子磁共振波谱（MRS）信号的纵向和横向弛豫时间。在健康受试者枕叶中选择主要包含灰质或白质的感兴趣区，并获得了以下共振峰的弛豫时间：2.01ppm处的N-乙酰天门冬氨酸（T(1)和T(2)）、2.35ppm处的谷氨酸（T(1)）、3.03和3.92ppm处的肌酸（T(1)和T(2)）、3.22ppm处的含胆碱物质（T(1)和T(2)）、3.57和3.65ppm处的肌醇（T(1)）以及3.75ppm处谷氨酸和谷氨酰胺的重叠信号（T(1)）。灰质的T(1)弛豫时间范围为0.97至1.47秒，白质的T(1)弛豫时间范围为0.87至1.35秒。另一方面，灰质和白质的T(2)弛豫时间分别为116至247毫秒和141至295毫秒。一般来说，在3T下测量的T(1)值与先前在1.5T、2T和4.1T下发表的数据相近。此外，T(2)值证实了先前观察到的横向弛豫时间随静磁场增加而缩短的现象。所获得的质子弛豫时间将有助于改进3T磁场下的序列设计和波谱定量分析，目前正针对增强临床应用进行测试。
