| Since1973, magnetic resonance imaging (MRI) has been widely used in many areas, such as biology, medicine and geological exploration, because of its many characteristics such as Noninvasive detection, high image contrast and so on.For the layout of MRI system, due to the strong magnetic field environment around the MRI system, receivers must be away from the magnet of MRI system. In the early times, when the Parallel imaging is implemented, the long cable is used to connect coils and receiver for signal transmission. However, in the practical application, some new problems, such as the interference among the long cables and the coupling between the electromagnetic environment and the cables, will make the MR image quality deteriorated. Nowadays, several solutions which can be divided into fiber optic links and wireless links, have been proposed and implemented to reduce electromagnetic interference. Although those solutions remove the interference effectively, there are still several defects. Firstly, in contrast to the dynamic range (DR) of raw MRI signal, the fiber-optic-link’s and wireless-link’s are so small that signal can be distorted. Secondly, the implementation requires complicated technology and high cost.The main work of this thesis is to develop one new way, Cable FM transmission method, to reduce the interference among the cables and environment. The thesis is divided into five parts:The first part briefly introduces MRI, phased-array coil and parallel imaging technology.The second part introduces briefly the present solution of the long cables’ interference in MRI system and the drawbacks of each.The third part mainly introduces the implementation of the Cable FM transmission method. The circuit’s test results will also be presented in this part.The forth part presents the implementation and test results of3channels butterfly phased-array coil for realization of Cable FM transmission method.The fifth part shows the results of image and the further discussion. |
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