MRI Digital Receiver Based On RF Direct Sampling Technology

Magnetic Resonance Imaging (MRI) is an important field Nuclear Magnetic Resonance Imaging (NMR) study. It has been more than 30 years since the first successful magnetic resonance imaging test. In 30 years time, with the rapid speed of development, MRI has now become an important research tool, and penetrated to the biology, chemistry, medicine, and other various subject areas. Since 1980, the first advent of commercial magnetic resonance imaging system, the technology of MRI system has developed rapidly. However, the core technology of MRI system is still in the hands of big foreign companies. Therefore, the independent research of MRI system not only has good scientific value, as well as practical significance.The main work of this thesis is to develop one of the core components of MRI spectrometer, digital receiver. Receiver for the past shortcomings, we proposed improvement. Use of direct sampling of RF and digital signal processor (DSP), we connected software radio theory with practical hardware design and implementation, and made in-depth research.This thesis is divided into 4 parts:The first part briefly describes the basic theories of NMR, MRI and MRI spectrometer technology.The second part mainly described the theory of software radio:Signal sampling theory, multispeed signal processing, digital orthogonal transform, and digital filters, etc. And I introduced original receiver in the lab combined with these theories.The third part mainly described the design of "MRI digital receiver based on RF direct Sampling technology", including the design ideas and specific hardware and software.The fourth part presents Intermediate results of debugging test results and the final MRI results.