STEAM和PRESS序列对磁共振频谱绝对定量的影响

The influence of STEAM and PRESS sequence on the absolute quantitation of ~1H-MR spectroscopy

目的:比较PRESS和STEAM序列对大脑中央前回的代谢物绝对定量的差异。方法:8例健康成年人,平均年龄26.1岁。使用PRESS序列及STEAM序列进行定量检测,实验参数为TE=30ms,TR=3000ms。扫描时间每次约30min。结果:PRESS和STEAM序列使用LCModel软件分析得出Cr的浓度存在显著的差异性,并认为实验结果与序列的特征以及受邻近代谢物峰值影响有关,而对NAA、Cho、Glx、MI、NAA/Cr、Cho/Cr、MI/Cr、Glx/Cr没有显著差异。结论:在短TE条件下,STEAM序列对绝对定量的准确性较PRESS序列稍高。在短TE情况下,Cr物质受到邻近物质峰值影响,使基线不平稳。

Objective：To analyze the metabolic concentration difference in anterior central gyrusby absolutely quantitative 1 H-MR spectroscopy combined with PRESS or STEAM sequences.Methods：8 healthy volunteers with an average age of 26.1 years old were selected in this study.All the 1 H-MR spectroscopy data were collected by PRESS and STEAM sequence.The scan parameters were as follows i.e,TE=30 ms,TR=300 ms.The duration of every examination was about half an hour.Results：The concentrations of Cr were statistically significant if we compared the data between PRESS and STEAM sequences with LCModel software.Conclusion：STEAM sequence is more sensitive for the short T2 metabolic,such as Glx and mI.The peak of Cr will be affected by the adjacent complicated metabolic peaks when the TE is quite short,which makes the baseline unsteadily.