The Research Of Ultra High Field MRI Rf Coil Technology And Real-time Monitor Systems

Ultra-high field magnetic resonance imaging (MRI) system is based on a large scale superconducting magnetic resonance technology to produce super steady magnetic field environment. Compared with the traditional MRI system, the ultra-high field MRI can produced higher resolution images. Therefore, the medicine,physics, chemistry and related interdisciplinary research can proceed based on a more elaborate magnetic resonance imaging results. In this case, the magnet field flux density is 9.4 T, so, the radio frequency power amplifier, the gradient amplifier and RF coil technology require different degrees of improvement. The ultra- high field MRI technology development is, in fact, the development of related technology synchronous with the main magnetic intense enhancing.In this thesis, all the main works were accomplished on the 9.4 T MRI system.The works mainly includes three parts: firstly, aiming at small mammals' MRI imaging, miniature in vitro tissue imaging applications and high resolution imaging applications under 9.4T, we designed the RF coil; Secondly, we explore effective RF coil optimization scheme by changing the conductor surface shape based on the traditional birdcage coil technology; Three, we design two sets of related auxiliary system for 9.4T MRI application: real-time video monitor system and multi-module switch control system.The finite element method (FEM) was adapt to analysis the RF electromagnetic field distribution and to simulate the RF coil. The capacitance with high power and low losses was adapted, as well as 3D printing materials and other non-magnetic materials with different parameters for RF coil production. The parameters were abstained with network analyzer and the images of vivo-animals, in vitro biological tissue, normal saline and many kinds of samples was acquired under the 9.4T MRI workbench. For the design of the real-time video monitor system and switch control system, the main program was based on LabVIEW software platform, using NI data acquisition card (DAQ) as the communicate equipment of the interaction between the control bench and experiment devices. The computer and network analyzer was used to conduce the experiments and data gathering under the 9.4 T MRI workbench.The main research of the thesis fully combined with practical application and, in high platform, based on the research methods, research process and the experimental results, the thesis goes to provide effective reference for RF coil and related additional applications of high field MRI technology for the further development.