MRI设备磁场均匀性评估方法探讨及实践

摘要

目的 探讨MRI设备磁场均匀性评估方法与实践操作步骤,为临床质量控制提供技术参考.方法 基于MRS模体和32 cm的匀场球模,分别采用波谱峰值法和带宽差值法两种磁场均匀性检测方法检测本单位放射科的MRI设备.结果 MRS模体的半高宽值为0.08 ppm,32 cm匀场球模在带宽差值法下单层冠状位,矢状位和轴位的磁场不均匀值分别为0.15 ppm、0.08 ppm和0.18 ppm.结论 所检测MRI设备磁场均匀性良好,符合磁场均匀性检测标准.%Objective To explore the evaluation methods of magnetic field uniformity and the practical operations,in order to provide references for clinical quality control.Methods Based on MRS phantom and 32 cm uniform spherical phantom,the evaluation methods of magnetic field uniformity were used to detect MRI equipment in department of radiology,including spectral peak and the bandwidth difference.Results The full width at half maximum (FWHM) of MRS phantom was 0.08 ppm,the inhomogeneity values on coronal,sagittal and axial detected by the bandwidth difference method was 0.15 ppm,0.08 ppm and 0.18 ppm,respectively.Conclusion The magnetic field homogeneity of the above mentioned MRI equipment is favorable,which accords with magnetic field uniformity detection standard.