主磁场不均匀情况下的磁共振虚拟成像初步研究  

The preliminary study of virtual magnetic resonance imaging in case of the main fi eld inhomogeneity

作　　者：骆国丽 肖亮[1] 

机构地区：[1]北京化工大学信息科学与技术学院,北京100029

出　　处：《磁共振成像》2015年第6期471-475,共5页Chinese Journal of Magnetic Resonance Imaging

摘　　要：目的设计实现一个基于布洛赫(Bloch)方程的磁共振成像模拟器,并以此仿真主磁场不均匀对成像的影响。材料与方法用C语言实现磁共振成像(magnetic resonance imaging,MRI)模拟器。成像过程中,虚拟物体各体素点的磁化强度矢量根据离散化Bloch方程递推计算得出。假定主磁场B0的不均匀性的几种模式,设定不均匀与其空间位置的关系,以此为代入条件进行模拟成像实验,并将结果与相应的实际成像对比。结果本MRI模拟器可以较好地模拟出主磁场不均匀对成像造成的影响,得到符合预期的成像结果。结论本MRI模拟器有助于工程与科研中分析主磁场不均匀对成像的影响。Objective： The purpose of this paper is to design a magnetic resonance imaging simulator based-on Bloch equation, which can be used to simulate the impact of the main field inhomogeneity to the virtual magnetic resonance imaging（MRI）. Materials and Methods： The magnetic resonance imaging simulator is implemented by C language. In the imaging process, the magnetization vector of each voxel in the virtual object is calculated by the discrete time solution of the Bloch equation. It assumes two different models of the main field inhomogeneity and assigns the spatial position matrix of inhomogeneity, which is used as the input of virtual MRI simulation. Compare the simulated images with the corresponding actual experimental images. Results： The MRI simulator allows the simulation of images impacted by the inhomogeneity of the main magnetic field. The imaging results can meet our expectation. Conclusion： The MRI simulator is helpful for engineering and scientifi c research in the analysis of the main magnetic fi eld inhomogeneity effects on imaging.

关 键 词：磁共振成像 虚拟成像 BLOCH方程 主磁场 

分 类 号：R445.2[医药卫生—影像医学与核医学] O441.4[医药卫生—诊断学]