Magnetic Resonance Imaging Data Transmission And Signal Processing Based On Seriallite Ⅱ Protocol

In magnetic resonance imaging(MRI),the echo signal induced by the receiving coil is generally transmitted to the spectrometer console in the equipment room through a coaxial cable for collection.There is attenuation and distortion in the signal,which will reduce the signal-to-noise ratio,and it is also susceptible to external interference.Another method is to transmit echomodulated analog optical signals through optical fibers,but there are still problems of signal-to-noise ratio reduction and signal interference to a certain extent.With the development of MRI technology,the application of high-speed imaging sequences is becoming more and more common,and the number of receiving channels is increasing,which requires the ability to upload the collected echo data to the spectrometer console at high speed and with low delay.In order to eliminate interference in signal transmission and improve the signal-to-noise ratio of collected echo signals,the signal collection device needs to be placed in a shielded room,as close as possible to the receiving coil,and the data is returned through the optical fiber.In response to this situation,this paper proposes an optical fiber data transmission scheme based on the SerialLite Ⅱ protocol to solve the problem of parameter configuration of signal acquisition and high-speed transmission of echo data.The main research contents are:(1)A magnetic resonance imaging data transmission system was developed with FPGA as the core,which has the advantages of high integration,flexible configuration,and good scalability.(2)By configuring the SerialLite Ⅱ protocol IP core and designing the control interface of the protocol,combined with the digital optical fiber transmission technology,a stable digital optical fiber link has been established to realize the high-speed data transmission function.(3)In order to facilitate programming,a Nios II soft-core processor is built in the FPGA,and the parameter configuration program of the signal acquisition module is written in C language.And through the timing design,the relevant events of the control signal acquisition are aligned in time,and the coherence of radio frequency transmission and reception is realized.(4)Research on the acquisition and processing of magnetic resonance echo signals is carried out,and digital quadrature demodulation and multi-rate signal processing are completed based on the digital down-converter,and the echo signal reception is accurately realized.(5)A multi-channel echo data transmission scheme is designed,and a large number of tests and experiments are carried out.The results show that the data transmission system can reliably realize parameter downloading and echo data uploading,and the time consumption of data transmission is very small.The research in this paper is helpful to improve the signal-to-noise ratio of echo signal acquisition,eliminate the interference of external environment in the transmission process,and improve the quality of MRI imaging.Provide technical support for the construction of multi-channel,high-performance magnetic resonance imaging spectrometers,thereby promoting the development of the domestic magnetic resonance imaging industry.