Üç boyutlu nesneler için indüklenen akımlar ile manyetik rezonans-elektriksel empedans görüntüleme

ABSTRACTTHREE DIMENSIONAL INDUCED CURRENTMAGNETIC RESONANCE - ELECTRIC IMPEDANCETOMOGRAPHYüLevent OzparlakM.S. in Electrical - Electronics Engineering˙Supervisor: Prof. Dr. Yusuf Ziya IderJune, 2004Human body contains different tissue types and these different tissue types havedifferent electrical resistivity characteristics. The property, that human body hasa large resistivity contrast among its different tissues, introduces us to impedanceimaging techniques. In this thesis, we try to find better reconstruction tech-niques to visualize impedance characteristic of human body. In addition to betterimaging, we try to obtain higher resolution images of three dimensional objectsthan existing imaging techniques. In order to achieve this goal, we proposed atechnique named Induced Current Magnetic Resonance - Electric Impedance To-mography (IC MR-EIT) which combines the peripheral voltage measurements ofInduced Current Electric Impedance Tomography technique with magnetic fluxdensity measurements acquired using a Magnetic-Resonance Image (MRI) Scan-ner. The advantage of this method is measurement noise due to electrode will notoccur. In this thesis, A new reconstruction algorithm for IC MR-EIT is proposedand computer simulations are made. The proposed algorithm is based on themeasurement of one component of the magnetic flux density created by the eddycurrents in the object. As can be seen in the results, the reconstruction of theconductivity distribution in three dimensional objects on tomographic planes ismade successfully. It also works fine against to the measurement noise up to anacceptable level.Keywords: Induced Current Magnetic Resonance - Electric Impedance Tomogra-phy, Magnetic Resonance Imaging, Impedance Imaging, Image Reconstruction,Finite Element Method.iii