Research On Key Technology Of Improving Signal To Noise Ratio Of Magnetic Resonance Spectrometer

Magnetic Resonance Imaging（MRI）has been widely used and plays an important role in clinical medical diagnosis and basic life science research.In recent years,magnetic resonance imaging technology has achieved rapid development in both hardware and application research.At present,the most effective way to improve the signal-to-noise ratio of magnetic resonance imaging system is the most commonly used method in the field of magnetic resonance imaging technology is to improve the strength of the main magnetic field,such as 7T ultra-high field magnetic resonance system.However,high field magnetic resonance system still has a lot of unsolved technical challenges and disadvantages,a variety of factors seriously limits for more than 7 t and high field magnetic resonance system’s usability and accessibility,so this theses puts forward the ascension magnetic resonance system signal-to-noise ratio of other solutions,in order to meet the clinical and scientific research institution demand for magnetic resonance imaging high signal-to-noise ratio.Magnetic resonance imaging system is mainly composed of computer,spectrometer,amplifier,coils,main magnet,etc,and spectrometer in the process of MRI plays a most important core functionality,it features control sequence of operation,producing rf signal and generates the spatial location signal,namely the gradient signal,and receive radio frequency signal and magnetic resonance image reconstruction,etc.It is obvious that the spectrometer plays an important role in the magnetic resonance system,so the main magnetic field is certain.The structure design of the spectrometer and the performance of the spectrometer largely determine the signal-to-noise ratio of the magnetic resonance imaging system.Therefore,the focus of this thesis is to study the key technologies of improving the Signal-to-Noise Ratio of magnetic resonance spectrometer.In this thesis,three key technologies of improving magnetic resonance spectrometer are proposed,which are over-sampling technology,noise disturbance technology and gain optimization technology.To the open literature research,sampling techniques and noise scrambling technology can improve the SNR of signal,and the two technologies also has been widely used in other areas,but not verified in the field of magnetic resonance（NMR）,based on the two technologies to sine wave signal,SINC signal and magnetic resonance signal simulation experiment was carried out respectively,The simulation results show that the over-sampling technique and noise jamming technique can improve the signal-to-noise ratio of magnetic resonance signal.In addition,this thesis also puts forward an optimized magnetic resonance K in different phase encoding method of the gain parameters,this method will be treated as 1 K space partition,based on the different area with different gain K space to promote the purpose of magnetic resonance image signal-to-noise ratio,concrete realization for the existing 3 t magnetic resonance system is set up under the condition of different gain parameters,Acquisition for high gain and signal of magnetic resonance（NMR）under low gain K space,then through the proposed splicing after joining together,and get the K space,space reconstruction after mosaics of the K for a magnetic resonance image signal-to-noise ratio analysis,and magnetic resonance imaging in this thesis,the single channel and eight channels of magnetic resonance images are analyzed,It is concluded that the gain optimization technique proposed in this thesis can effectively improve the signal-to-noise ratio of magnetic resonance images.