基于磁共振频谱(MRS)定量检测人脑γ-氨基丁酸(GABA)浓度对医学临床意义重大。除了用频谱处理软件包进行处理外,谱分析的方法能更为直接地检测GABA。本研究用双量子滤波技术(DQF)去设计和优化用于检测GABA的脉冲序列,基于乘积算符理论和相干路径选择理论,设计GABA谱编辑序列。通过MRUI模拟实验,本研究证实了优化的序列能压制位于化学位移3.0ppm处的肌酸(Cr),从而使低浓度的GABA信号明显增强,最后,本研究编程实现了优化的脉冲序列。进一步工作是将该序列的目标程序应用到临床MRI扫描仪上验证,优化其的参数,并通过模型实验和活体实验验证本序列的性能。
In vivo detection of GABA in human brain using MRS is important for clinical research. Besides the usage of quantitative software packages, the spectral editing for MRS data is a direct method for measuring GABA in vivo. We utilized DQF technology in the design and optimization of pulse sequence for the measurement of GABA, adopted product operator and coherence selection theories to explain the pulse sequence design process. In the simulation of MRUI experiment, it was obvious that the Cr signal at δ3.0 ppm was suppressed and the very low GABA signal was enhanced with the optimized pulse sequence. And we realized the designed optimal pulse sequence. The object program for generating the pulse sequence is expected to be testified on clinical MRI scanners, optimizing the scanning parameter and testing the function of the pulse sequence in phantom experiments and human experiments.