Fast full-wave calculation of electromagnetic fields based on weak-form volume integral equation for MRI applications

• Published in: Journal of engineering (Stevenage, England) Vol. 2018; no. 9; pp. 762 - 767
• Main Authors: Huang, Shao Ying, Ma, Zu-Hui, Wan, Luo, Yu, Wenwei, Vaughan, J. Thomas
• Format: Journal Article
• Language: English; Japanese
• Published: The Institution of Engineering and Technology 01.09.2018; Institution of Engineering and Technology (IET)
• Subjects: accurate calculations; biomedical MRI; dielectric materials; electromagnetic fields; electromagnetic wave scattering; EM field; fast Fourier; fast Fourier transforms; fast full‐wave calculation; high speed; high‐field magnetic resonance imaging scans; human body; input energy budgeting; integral equations; iterative methods; MRI applications; MRI system; near‐field calculations; Research Article; safety problems; temperature distributions; VIE; weak‐form volume integral equation; fast Fourier transforms; iterative methods; biomedical MRI; high-field magnetic resonance imaging scans; high speed; fast full-wave calculation; human body; dielectric materials; input energy budgeting; electromagnetic wave scattering; weak-form volume integral equation; integral equations; accurate calculations; VIE; electromagnetic fields; temperature distributions; fast Fourier; safety problems; MRI system; EM field; MRI applications; near-field calculations
• ISSN: 2051-3305; 2051-3305
• DOI: 10.1049/joe.2018.0122

High-field magnetic resonance imaging (MRI) scans have safety problems because energy is not homogeneously distributed in the human body. A prescan where energy and temperature distributions are calculated for input energy budgeting can significantly lower the risk. Therefore, fast and accurate calculations of the electromagnetic (EM) fields of an MRI system with a subject under scan are needed. Here, the authors present a fast EM solver based on a weak-form volume integral equation (VIE) for solving this problem. The proposed approach calculates the EM field inside the human body at a high speed without sacrificing accuracy. In the proposed approach, the VIE formulation for an inhomogeneous dielectric object is employed for near-field calculations. The operation on a dense matrix resulted by the VIE is accelerated by fast Fourier transform (FFT) in conjunction with the latest efficient iterative method. Numerical experiments are presented to show the speed and accuracy of the proposed EM solver.