Tkáč I, Gruetter R
Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, USA.
Appl Magn Reson. 2005 Mar;29(1):139-157. doi: 10.1007/BF03166960.
An ultrashort-echo-time stimulated echo-acquisition mode (STEAM) pulse sequence with interleaved outer volume suppression and VAPOR (variable power and optimized relaxation delays) water suppression was redesigned and optimized for human applications at 4 and 7 T, taking into account the specific requirements for spectroscopy at high magnetic fields and limitations of currently available hardware. In combination with automatic shimming, automated parameter adjustments and data processing, this method provided a user-friendly tool for routine (1)H nuclear magnetic resonance (NMR) spectroscopy of the human brain at very high magnetic fields. Effects of first- and second-order shimming, single-scan averaging, frequency and phase corrections, and eddy currents were described. LCModel analysis of an in vivo (1)H NMR spectrum measured from the human brain at 7 T allowed reliable quantification of more than fifteen metabolites noninvasively, illustrating the potential of high-field NMR spectroscopy. Examples of spectroscopic studies performed at 4 and 7 T demonstrated the high reproducibility of acquired spectra quality.
一种具有交错外部容积抑制和VAPOR（可变功率和优化弛豫延迟）水抑制的超短回波时间刺激回波采集模式（STEAM）脉冲序列，针对4T和7T的人体应用进行了重新设计和优化，同时考虑到高磁场下光谱学的特定要求以及现有硬件的局限性。结合自动匀场、自动参数调整和数据处理，该方法为在非常高的磁场下对人脑进行常规氢核磁共振（NMR）光谱分析提供了一种用户友好的工具。描述了一阶和二阶匀场、单扫描平均、频率和相位校正以及涡流的影响。对在7T下从人脑测量的体内氢NMR光谱进行LCModel分析，能够可靠地无创定量超过十五种代谢物，说明了高场NMR光谱学的潜力。在4T和7T下进行的光谱学研究示例证明了所采集光谱质量的高重现性。
