Magnetic Resonance Electrical Impedance Tomography (MREIT) reconstructs
conductivity distribution with internal current density (MRCDI) and boundary
voltage measurements. There are many algorithms proposed for the solution of
MREIT inverse problem which can be divided into two groups: Current density (J)
and magnetic flux density (B) based reconstruction algorithms. In this thesis, J-based
MREIT reconstruction algorithms are implemented and optimized with
modifications. These algorithms are simulated with five conductivity models which
have different geometries and conductivity values. Results of simulation are
discussed and reconstruction algorithms are compared according to their
performances. Equipotential-Projection algorithm has lower error percentages than
other algorithms for noise-free case whereas Hybrid algorithm has the best
performance for noisy cases. Although J-substitution and Hybrid algorithms have
relatively long reconstruction times, they produced the best images perceptually.
v
Integration along Cartesian Grid Lines and Integration along Equipotential Lines
algorithms diverge as noise level increases. Equipotential-Projection algorithm has
erroneous lines starting from corners of FOV especially for noisy cases whereas
Solution as a Linear Equation System has a typical grid artifact. When performance
with data of experiment 1 is considered, only Solution as a Linear Equation System
algorithm partially reconstructed all elements which show that it is robust to noise.
Equipotential-Projection algorithm reconstructed resistive element partially and other
algorithms failed in reconstruction of conductivity distribution. Experimental results
obtained with a higher conductivity contrast show that Solution as a Linear Equation
System, J-Substitution and Hybrid algorithms reconstructed both phantom elements
and Hybrid algorithm is superior to other algorithms in percentage error comparison.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12611016/index.pdf |
| Date | 01 September 2009 |
| Creators | Boyacioglu, Rasim |
| Contributors | Eyuboglu, Murat Behcet |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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