Comparison of three artificial models of the magnetohydrodynamic effect on the electrocardiogram
Journal
Computer Methods in Biomechanics and Biomedical Engineering
Journal Volume
18
Journal Issue
13
Pages
1400-1417
Date Issued
2015
Author(s)
Abstract
The electrocardiogram (ECG) is often acquired during magnetic resonance imaging (MRI), but its analysis is restricted by the presence of a strong artefact, called magnetohydrodynamic (MHD) effect. MHD effect is induced by the flow of electrically charged particles in the blood perpendicular to the static magnetic field, which creates a potential of the order of magnitude of the ECG and temporally coincident with the repolarisation period. In this study, a new MHD model is proposed by using MRI-based 4D blood flow measurements made across the aortic arch. The model is extended to several cardiac cycles to allow the simulation of a realistic ECG acquisition during MRI examination and the quality assessment of MHD suppression techniques. A comparison of two existing models, based, respectively, on an analytical solution and on a numerical method-based solution of the fluids dynamics problem, is made with the proposed model and with an estimate of the MHD voltage observed during a real MRI scan. Results indicate a moderate agreement between the proposed model and the estimated MHD model for most leads, with an average correlation factor of 0.47. However, the results demonstrate that the proposed model provides a closer approximation to the observed MHD effects and a better depiction of the complexity of the MHD effect compared with the previously published models, with an improved correlation ((Formula presented.)), coefficient of determination ((Formula presented.)) and fraction of energy ((Formula presented.)) compared with the best previous model. The source code will be made freely available under an open source licence to facilitate collaboration and allow more rapid development of more accurate models of the MHD effect. ? 2014, ? 2014 Taylor & Francis.
Subjects
Blood
Charged particles
Electrocardiography
Magnetic resonance imaging
Models
Numerical methods
Open source software
Open systems
Blood flow measurement
Coefficient of determination
Correlation factors
Magnetic Resonance Imaging (MRI)
Magnetohydrodynamic effects
Open-source licence
Static magnetic fields
Suppression technique
Magnetohydrodynamics
aorta
artifact
biological model
comparative study
computer simulation
electrocardiography
Fourier analysis
human
hydrodynamics
nuclear magnetic resonance imaging
pathology
signal processing
thoracic aorta
Aorta
Aorta, Thoracic
Artifacts
Computer Simulation
Fourier Analysis
Humans
Hydrodynamics
Magnetic Resonance Imaging
Models, Cardiovascular
Signal Processing, Computer-Assisted
Type
journal article