Designed And Programmed The Pulse Sequence For Measurement Of γ-aminobutyric Acid In Vivo Using MR Spectroscopy

It's a worldwide puzzle that in vivo detection of GABA in human brain using we haven'tsearched any reportorial research work on the subject in domestic, and three are only a fewresearch groups engaged in the subject at abroad, but their researches are still in the exploringstage and haven't found a reliable technique to detect GABA in vivo.The objective of my study aimed on measuring GABA in vivo with spectral editing of MRSdata. My dissertation mainly discussed three aspect of the spectral editing method. First, westudied the design theory of pulse sequence, discussed how does the sequence pulse workeffectively, and described its mathematical formula. It maybe helpful for the pulse sequencedesign and program. Second, we utilized DQF technology in the design and optimization ofpulse sequence for measurement of GABA, adopted product operator and coherence selectiontheories to explain the pulse sequence design process. In the simulation of MRUI experiment, itwas obvious that the Cr signal atδ3.0 was suppressed and the very low GABA signal wasenhanced clearly with the optimized pulse sequence. Third, we employed the Shinnar-LeRouxarithmetic to design RF pulse, used the MR pulse sequence program workstation, EPIC, toaccomplish the designed pulse sequence program. The designed pulse sequence was also appliedon the Bruker scanner phantom experiment. It demonstrated that the DQF technology was aneffective measurment of detecting GABA. The security must pre-requisite consider problem inthe process of designing pulse sequence, we attached importance to the impact of RF pulse andgradient field pulse, promoted the method of calculating the SAR value of RF pulses andprogrammed it.In my dissertation, I had successfully programmed the designed pulse sequence. Theposteriors can transfer the object program to the GE Sigma 1.5T workstation, optimize thescanning parameter, and test the function of the pulse sequence in phantom experiments andhuman experiments. These work maybe the first research on GABA measument using MRS inChina, and may provide a useful tool for clinical pathological researchers. Also, themathematical formula of pulse sequence and theory of pulse design will help the posteriors tounder pulse sequence and design pulse sequence.