永磁微型磁共振成像仪的梯度线圈与图像质量  

Gradient Coil of Permanent Magnet Mini-Magnetic Resonance Imager and Image Quality

作　　者：侯淑莲[1] 谢寰彤 侯晓吻[3] 李石玉[1] 陈伟[1] 

机构地区：[1]河北联合大学基础医学院,河北唐山063000 [2]上海寰彤科教设备有限公司,上海201806 [3]杭州电子科技大学,浙江杭州310000

出　　处：《波谱学杂志》2012年第4期508-520,共13页Chinese Journal of Magnetic Resonance

基　　金：河北省科学技术厅科研计划资助项目(08202133D)

摘　　要：通过理论分析结合计算机仿真试验剖析了磁共振成像(MRI)中梯度场线性对图像质量影响的原理,在梯度场线性有缺陷的情况下,用实例和计算机模拟直观的展示了重建图像和模拟结果.结合研发实践发现,在永磁微小口径、低场强用于鼠类等小动物成像情况下,对梯度场线性度的要求远高于文献中提出的指标.依靠软件改进,图像没有本质的提高,尝试补偿技术耗时费力效果也不理想.说明了对永磁微小口径成像仪研发线性度更好的梯度线圈是提高图像质量的关键技术之一.揭示了在理想条件下普适的理论原理,在不同的实践条件下有不同的趋近理想条件要求.将具有独立知识产权的高线性梯度线圈安装在自行研制的仪器上得到了较好的图像.Effects of gradient field linearity on the quality of images acquired on a perma- nent magnet mini-magnetic resonance imager were analyzed by theoretical analyses and numerical simulation. It was shown that gradient field with high linearity is a prerequisite to obtain high-quality images of small animals, such as mice, on permanent magnet, low field strength micro-magnetic resonance imagers. The gradient field linearity specification reported in the literature is too low to acquired high-quality mouse images. The image quality could not be improved by software compensation methods. The newly developed gradient field coil with high linear property and our independent intellectual property was also presented. The optimized gradient coil has been installed on our instrument, and yielded a better quality image.

关 键 词：磁共振成像(MRI) 永磁微型三维磁共振成像仪 线性 梯度线圈 计算机仿真 

分 类 号：R318.6[医药卫生—生物医学工程] R332[医药卫生—基础医学]