High-speed Transmission Of Magnetic Resonance Acquistion Data Based On FPGA And Optical Fiber Devices

Magnetic Resonance Imaging(MRI)is an imaging technology commonly used in the medical field.Externally radiated radio frequency signals,the echo signals are collected and reconstructed in a specific way to obtain human body images.Traditionally,the RF echo signal of MRI is collected from the low-noise preamplifier in the shielded room to the spectrometer in the equipment room through a coaxial cable.In this case,the transmission of the analog signal must be attenuated and easily interfered..Therefore,in order to improve the signal-to-noise ratio of MRI echo signal acquisition and improve the anti-interference ability,it is hoped to place the echo signal acquisition in a shielded room(as close as possible to the low-noise preamplifier),and transmit the acquisition to the spectrometer in the equipment room through optical fiber.echo data.Optical fiber-based signal transmission has the advantages of wide channel,low attenuation,and anti-interference.On the other hand,Field Programmable Gate Array(FPGA)devices have the characteristics of parallelism,high speed and rich functions,and can realize high-speed data transmission in combination with optical fiber devices.Based on this,the research of this topic is based on FPGA and optical fiber devices to achieve high-speed transmission of high-field magnetic resonance acquisition data.The main research work includes:(1)A digital signal transmission circuit based on optical fiber devices was developed,and the digital signal transmission performance of optical fiber was verified.(2)In order to realize the parameter configuration of signal amplification,sampling and digital demodulation,a transmission method of configuration parameters based on FPGA is developed,which realizes the accurate transmission and reception of the configuration parameters of signal acquisition through the optical fiber.(3)In order to improve the transmission speed of echo data based on optical fiber,a new encoding method is proposed according to the characteristics of the magnetic resonance echo signal.Each 16-bit data is inverted at every interval,and then according to the number of 0 and 1 and the Permutations dynamically insert specific bits for DC equalization.The method is implemented and verified based on FPGA,and compared with the traditional 8b/10 b encoding,the amount of data can be significantly reduced.(4)The frequency of the echo signal is high under high field conditions,and it needs to be down-mixed before receiving.Therefore,an analog local oscillator signal transmission circuit based on optical fiber devices is developed to realize the low-distortion transmission of the local oscillator signal to ensure The quality of the downmix.The research work of the subject will help to realize the high-performance,fiber-based magnetic resonance acquisition data transmission equipment,thereby improving the signal-to-noise ratio of the acquired signal and reducing the interference,so as to achieve the purpose of improving the imaging quality.Considering that my country’s magnetic resonance imaging industry and technology are in the stage of vigorous development,the subject research has certain application prospects.