注入及感应电流磁共振电阻抗成像对比

为了对比注入电流磁共振电阻抗成像(MREIT)及感应电流磁共振电阻抗成像(IC-MREIT)用于重构人体头部组织电导率分布的性能,分别在3层球头模型及包含5种组织的真实头模型上进行仿真.正问题仿真结果表明：在满足人体安全性要求的前提下,2种成像方法在头部组织内产生的电流密度的强度处于同一数量级,但IC-MREIT产生的电流密度略大且分布受颅骨影响较小.基于J-substitution算法的逆问题仿真结果表明：对于3层球头模型,IC-MREIT能够在较少的迭代次数内,以更高的精度重构出电导率分布；对于真实头模型,MREIT具有更好的收敛特性和成像精度.

Comparison between injected current and induced current magnetic resonance electrical impedance tomography

The simulations were conducted on the three sphere head model and five compartment realistic head model in order to evaluate the performance of the injected current magnetic resonance electrical impedance tomography (MREIT) and the induced current magnetic resonance electrical impedance tomography (IC-MREIT) to image the conductivity distribution of head-brain tissues. The simulation results of the forward problem show that the current densities in the head produced by MREIT and IC-MREIT are of the same order of magnitude when the safety requirement is satisfied. The current density produced by IC-MREIT is a little larger and is less affected by the skull. The simulation results of the inverse problem based on the J-substitution algorithm indicate that IC-MREIT can image the conductivity distribution with higher accuracy than MREIT in less iterations for the three sphere head model; the convergence behavior and imaging precision of MREIT are superior to IC-MREIT for the realistic head model.