Olsson M B, Wirestam R, Persson B R
Department of Radiation Physics, Lund University Hospital, Sweden.
Magn Reson Med. 1995 Oct;34(4):612-7. doi: 10.1002/mrm.1910340418.
A computer simulation program capable of demonstrating various artifacts, such as image distortion caused by metallic implants in MR imaging, is presented. The structure of the program allows for the implementation of various imaging situations as long as spins only experience weak interaction, i.e., the Bloch equations are obeyed. The raw data are obtained by repeatedly applying the Bloch equations to the magnetization vector of each point of the simulated object, throughout the pulse sequence. With only a limited number of spins in each voxel, the effects of intravoxel dephasing and rephasing require special attention, and algorithms for this have been implemented.
本文介绍了一种计算机模拟程序，该程序能够演示各种伪影，例如磁共振成像中金属植入物引起的图像失真。只要自旋仅经历弱相互作用，即遵守布洛赫方程，该程序的结构就允许实现各种成像情况。在整个脉冲序列中，通过对模拟对象每个点的磁化矢量反复应用布洛赫方程来获取原始数据。由于每个体素中只有有限数量的自旋，因此体素内去相位和重相位的影响需要特别关注，并且已经实现了针对此的算法。
