磁共振成像设备永磁体的匀场设计及检测技术

磁共振成像设备中,磁体系统属于重要结构,而磁场的均匀性与稳定性,是磁体系统成像质量高低的2个重要影响因素。该文以0.35 T永磁体作为研究对象,以单贴片矫正磁场矩阵数学模型为基础,完成匀场半径规划,采取逐渐叠加增补的规划方式,并对比分析匀场前后磁体的均匀性。之后,设计用于检测磁共振主磁场均匀性的探测器,并采取计算机仿真方法,对比分析不同测点的检测结果,最终证实匀场设计的高效性,由于新检测方法能够连续性获取磁场平面均匀度,检测结果较为精准与可靠。

Among the magnetic resonance imaging equipment,the magnet system is an important structure,and the uniformity and stability of the magnetic field are two important factors affecting the imaging quality of the magnet system.In this paper,taking the 0.35 T permanent magnet as the research object,based on the mathematical model of single patch correction magnetic field matrix,the planning of shimming radius is completed,the planning method of gradual superposition and supplement is adopted,and the uniformity of magnets before and after shimming is compared and analyzed.After that,a detector is designed to detect the uniformity of the main magnetic field of magnetic resonance,and the computer simulation method is adopted to compare and analyze the detection results of different measuring points,which finally proves the high efficiency of the shimming design.Since the new detection method can continuously obtain the plane uniformity of the magnetic field,the detection results are more accurate and reliable.