Open Permanent Magnet Mri Spectrometer Software System Research And Design

MRI(Magnetic Resonance Imaging) is an advanced measures of diagnosis and treatment. By this way, image can be acquired in every direction of any tissue section of body parts, and there are a lot of image parameters can be adjusted. Therefore, MRI has its own feature in display of the location, range, and contrast of the tissue.The development direction of MRI includes superconduct and permanent magnet type, and the latter can economize purchasing and maintenance cost so that it is the first choice for medical institutions, especially the small and medium hospital. Benefit from the improvement and optimization of the manufacturer and the application of the computer, it has more kinds of image methods. And the open structure can avoid the claustrophobia of some people, make it possible to offer invasive operation in situ observation. The spectrometer, which is the core component of MRI, has important significance in the popularization of MRI and the improvement of the medical treatment. This paper carries out research on the application software system of the spectrometer based on the domestic demand.The main contents of the dissertation are as follows:1、The basic structure of the spectrometer. This paper briefly introduces the hardware structure and functions. The spectrometer is mainly constituted by the central control unit and other controllers, which are network interface controller, RF transmitter controller, RF receiver controller, gradient generator and pulse sequence controller. The central control unit adopts the FPGA as the kernel control device and also the pulse sequence controller to provide trigger signal to the RF controller and the gradient controller by the digital gated trigger mode.The design of the software system. First is the requirement analysis and subsequently putting forward the design target and the overall structure. Whereafter, the function and the design scheme of each module is introduced in detail. One of the imaging characteristics of MRI is the abundant information of the image with multi-plane and multi-parameter. Based on this, providing relevant functions in the software can improve the lesion detection rate. The system is divided into sequence management module, K-space data management module, operation module, and communication module for routine inspection. The emphasis of design is the sequence and the adjustment of the image location. The pulse sequence modules and K-space data management module is described in separate chapters. The pulse sequence, which can be called directly, and need to be adjusted depending on the imaging parameters. It can also be designed with a custom text editor and graphical editor. The text sequence is written in C++language, based on static factory pattern to improve the sequence of class encapsulation. K-space data management module takes a certain kind of K-space filling patterns which mainly divided into two major categories of the Cartesian coordinates and a non-Cartesian coordinates based on the type of sequence. The Communication module for data interaction between the host computer and the spectrometer includes the K-space raw data collected in the time series data to generate a specific pulse sequence. The spectrometer manipulation module is the main computer control, such as start or stop scanning spectrometer operating status.The test of the software. The display of the graphical sequence editor and the geometry information editor and the reference lines editor is showed for test.The subsequent development goals. The functions of the software needs further improvement in future work to makes it more practical, such as the implementation of the interaction process of the data and the command.