Magnetic Field Mapping in the Magnetic Resonance Imaging System Using Genetic Algorithms

The magnetic field mapping is a useful tool to design and analysis the magnetic field, especially during the installation and the regular maintenance of the magnetic field generated by the Magnetic Resonance Imaging (MRI) system. The paper presents a magnetic field mapping method for the region of interesting (ROI) in the MRI system with the help of Genetic Algorithm (GA) method. According to the equations of the magnetic field in the cylindrical coordinate system, and the shape of ROI in the MRI system, the measurement points are carefully arranged on the surface of a cylinder in the center of the MRI system to simplify the operation of the sensors in the mapper. And the parameters in the mapping method are optimized to obtain an accurate result of magnetic field mapping. At last, an example of magnetic field mapping in a practical MRI system illustrates the efficiency and the flexibility of the mapping method.