基于7 T MRS利用量子滤波技术检测GABA序列设计及对比  

Design and comparison of pulse sequence for detection of γ-aminobutyric acid using double quantum filter at 7 T MR spectroscopy

作　　者：董静[1,2] 邱庆春[3] 沈智威[1] 章桃 聂婷婷[2] 贾岩龙[2] 吴仁华[2] 

机构地区：[1]汕头大学理学院,汕头515063 [2]汕头大学医学院第二附属医院放射科,汕头515041 [3]汕头大学医学院,汕头515041

出　　处：《磁共振成像》2015年第2期141-144,共4页Chinese Journal of Magnetic Resonance Imaging

基　　金：国家自然科学基金重点项目(编号:30930027)

摘　　要：目的通过对7T核磁共振仪序列进行修改和编译，实现量子滤波技术的应用，通过试管模型实验对可实现在体检测γ-氨基丁酸（Gamma-aminobutyricacid，GABA）的有效性进行分析比较，对后续活体动物及人体实验提供町靠依据。材料与方法双量子滤波技术在7T核磁共振扫描仪上应朋于GABA的检测。在点分辨自旋同波序列基础上编辑新的双量子滤波序列，同时改变量子滤波射频脉冲的波形（Gauss脉冲和Sinc脉冲），比较不同波形对检测具有γ-氨基丁酸的溶液模型的有效性。结果序列检测的有效性和非耦合抑制性效果数据通过分析处理得到，检测到的3．01ppm处的GABA信号和被抑制的重叠的代谢物信号是南选择性双量子滤波脉冲配合滤波梯度得以实现。结论编译的双量子滤波序列可以获得在3.01ppm处的GABA信号，谱编辑分析得出其检测效率为30％~40％；通过谱编辑对结果的分析，不同波形的射频脉冲对GABA检测效果不同，可观察到Gauss波形射频脉冲检测的有效性，但两种波形脉冲对肌酸和胆碱抑制效果都较明显；双量子滤波序列改变TR（Repetitiontime）或TE（Echotime）时对GABA的检测效率有较大影响。Objective： In this paper, the Double Quantum Filter （DQF） sequence and its functions and detection efficiency in measuring γ-aminobutyric acid （GABA） are studied, compared and developed in phantom experiments.The result can provide a basis for later human clinical. Materials and Methods： A point-resolved spectroscopy （PRESS） -localized double quantum filter （DQF） was applied to the detection of GABA at 7 T Magnetic resonance spectrum （MRS）. At the same time, the detection efficiencies of different sequences were compared by changing the RF pulse waveform （Sinc and Gauss） of DQF in phantom experiments. Results： In phantom experiments, the optimal echo time, the editing efficiency and the degree of suppression of uncoupled resonances were examined after numerical analysis of the editing performance. Conclusions： Excellent GABA signal retention at 3.01 ppm and robust suppression of the signals of the overlapping metabolites was achieved due to Double Quantum Filter （DQF） sequence. The spectral editing efficiency was measured to be 30%-40%. The detection effect was different for using different RF pulse. It is noticed that the detection efficiency of Gauss RF pulse is reasonably high. The suppression effect of Cr was obvious. The Cho can be suppressed effectively, too. In our experiments, we found that different TR （Repetition time） or TE （Echo time） has different effects on the results of MRS detection efficiency in measuring γ-aminobutyric acid.

关 键 词：GABA 双量子滤波 脉冲序列 MRS 谱编辑 

分 类 号：R445.2[医药卫生—影像医学与核医学] R-331[医药卫生—诊断学]