MRS双量子相干滤波技术在体检测GABA和GSH的研究现状

In Vivo Detection of GABA and GSH Using a Double Quantum Coherence Filter on Magnetic Resonance Spectroscopy:A Review

目的:γ-氨基丁酸(GABA)是维持正常脑功能的一种重要的抑制性神经递质。谷胱甘肽(GSH)是主要的抗氧化剂同时对活性氧分子的解毒起到重要作用。本文综述了双量子相干滤波脉冲序列技术在体检测GABA和GSH的最新研究进展。方法:磁共振频谱(MRS)技术非介入在体检测脑内代谢物是一种无损检测的方法。同时利用磁共振扫描仪的点分辨自旋回波(PRESS)定位方法,结合双量子相干滤波技术对γ-氨基丁酸(GABA)和谷胱甘肽(GSH)浓度进行在体检测。结果:GABA和GSH在人体的相对浓度很低以及与其他信号的重叠,用传统的技术很难检测到。实验证明经过优化的双量子相干方法可以在单次激发中鲁棒性地抑制其它信号(如胆碱、肌酸和天门冬氨酸),更好地获得GABA和GSH检测信号。结论:本文描述了多量子滤波(MQF)技术和双量子相干(DQC)滤波机制,从定位序列及读出脉冲设计、滤波梯度校准、相位校准三个方面,综述了DQC滤波脉冲序列技术最新研究进展。同时,探讨了双量子滤波方法在临床上的应用,还展望了MRS中双量子相干滤波技术在临床医学的发展方向。

Purpose：γ-aminobutyric acid（GABA） is the major inhibitory neurotransmitter for the normal function of human brain.Glutathione（GSH）,a primary antioxidant,plays an important role in protecting reactive molecules in living cells against oxidative damage.In this paper,an overview of new DQC filter sequence currently used to detect GABA and GSH was given.Methods：Spectral editing of cerebral metabolite concentrations by magnetic resonance spectroscopy（MRS） is an unique tool for in vivo non-invasive investigation.The point-resolved spin echo（PRESS）-localized double quantum coherence filter was implemented on MR scanner for the quantification of γ-aminobutyric acid（GABA） and Glutathione（GSH） concentrations in vivo.Results：It is difficult to detect GABA and GSH signal with the conventional technique due to its relatively low concentration and overlapping with other signals.The optimized double-quantum coherence method provided robustness by experiments,single-shot suppression of uncoupled resonances from choline,creatine,and NAA and obtained detection of the GABA and GSH signal with a better efficiency.Conclusions：In this article,the background knowledge of multiple quantum filter（MQF） and double quantum coherence（DQC） filter mechanism were briefly reviewed,and based on the following three elements：localization sequence and read pulse design,filter gradient calibration,phase calibration,an overview of new DQC filter sequence currently was given.The results published so far were promising and encourage further exploitation of the utility of DQF in clinical practice.In the end,proposals of further studies of DQC filter technique in MRS were mentioned.