Current constrained voltage scaled reconstruction (CCVSR) algorithm for MR-EIT and its performance with different probing current patterns
Date
2003Source Title
Physics in Medicine and Biology
Print ISSN
0031-9155
Publisher
Institute of Physics Publishing
Volume
48
Issue
5
Pages
653 - 671
Language
English
Type
ReviewItem Usage Stats
276
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views
274
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downloads
Abstract
Conventional injected-current electrical impedance tomography (EIT) and magnetic resonance imaging (MRI) techniques can be combined to reconstruct high resolution true conductivity images. The magnetic flux density distribution generated by the internal current density distribution is extracted from MR phase images. This information is used to form a fine detailed conductivity image using an Ohm's law based update equation. The reconstructed conductivity image is assumed to differ from the true image by a scale factor. EIT surface potential measurements are then used to scale the reconstructed image in order to find the true conductivity values. This process is iterated until a stopping criterion is met. Several simulations are carried out for opposite and cosine current injection patterns to select the best current injection pattern for a 2D thorax model. The contrast resolution and accuracy of the proposed algorithm are also studied. In all simulation studies, realistic noise models for voltage and magnetic flux density measurements are used. It is shown that, in contrast to the conventional EIT techniques, the proposed method has the capability of reconstructing conductivity images with uniform and high spatial resolution. The spatial resolution is limited by the larger element size of the finite element mesh and twice the magnetic resonance image pixel size.
Keywords
AlgorithmsComputer simulation
Current density
Electric impedance tomography
Image reconstruction
Magnetic flux
Phase images
Magnetic resonance imaging
Accuracy
Algorithm
Analytical error
Computer assisted impedance tomography
Contrast enhancement
Controlled study
Electric conductivity
Electric current
Electric potential
Image analysis
Image processing
Image reconstruction
Mathematical computing
Noise measurement
Nuclear magnetic resonance imaging
Radiation dose distribution
Simulation
Thorax
Algorithms
Electric Impedance
Electromagnetic Fields
Humans
Image Interpretation, Computer-Assisted
Magnetic resonance imaging
Radiometry
Reproducibility of results
Sensitivity and specificity
Tomography
Permalink
http://hdl.handle.net/11693/38214Published Version (Please cite this version)
http://dx.doi.org/10.1088/0031-9155/48/5/307Collections
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