论文标题
谐波$ b_z $算法的收敛分析,单个注射电流
Convergence analysis of the harmonic $B_z$ algorithm with single injection current in MREIT
论文作者
论文摘要
磁共振电阻抗层造影术(MREIT)旨在使用组织内部磁通密度的部分信息恢复对象的电导率分布,可以使用MRI扫描仪进行测量,并具有比涉及表面测量值的现有EIT技术相比,可以提供更高的电导率图像空间分辨率图像的空间分辨率。传统的MREIT重建算法使用两个线性独立注射电流获得的两个数据集。但是,在诸如经颅电刺激之类的应用中通常不可能注入两种电流。最近,我们提出了一种迭代电导率重建算法,称为单电流谐波$ b_z $算法,该算法在数值和幻影测试中表现出令人满意的性能。在本文中,我们对迭代序列的收敛性进行了严格的数学分析,以实现该算法。我们证明,在确切的电导率上应用一些温和的条件,迭代序列在明确的误差结合内收敛到真实解决方案。这种理论结果证实了所提出算法的合理性和效率。我们还提供了更多的数值证据来验证这些理论结果。
Magnetic resonance electrical impedance tomography (MREIT) aims to recover the electrical conductivity distribution of an object using partial information of magnetic flux densities inside the tissue which can be measured using an MRI scanner, with the advantage that a higher spatial resolution of conductivity image can be provided than existing EIT techniques involving surface measurements. Traditional MREIT reconstruction algorithms use two data sets obtained with two linearly independent injected currents. However, injection of two currents is often not possible in applications such as transcranial electrical stimulation. Recently, we proposed an iterative conductivity reconstruction algorithm called the single current harmonic $B_z$ algorithm that demonstrated satisfactory performance in numerical and phantom tests. In this paper, we provide a rigorous mathematical analysis of the convergence of the iterative sequence for realizing this algorithm. We prove that, applying some mild conditions on the exact conductivity, the iterative sequence converges to the true solution within an explicit error bound. Such theoretical results substantiate the reasonability and efficiency of the proposed algorithm. We also provide more numerical evidence to validate these theoretical results.