Effects of scanning and reconstruction parameters on image quality in magnetic particle imaging

buir.advisorÇukur, Emine Ülkü Sarıtaş
dc.contributor.authorBozkurt, Ecem
dc.date.accessioned2018-01-25T10:28:39Z
dc.date.available2018-01-25T10:28:39Z
dc.date.copyright2018-01
dc.date.issued2018-01
dc.date.submitted2018-01-24
dc.departmentDepartment of Electrical and Electronics Engineeringen_US
dc.descriptionCataloged from PDF version of article.en_US
dc.descriptionThesis (M.S.): Bilkent University, Department of Electrical and Electronics Engineering, İhsan Doğramacı Bilkent University, 2018.en_US
dc.descriptionIncludes bibliographical references (leaves 55-59).en_US
dc.description.abstractMagnetic particle imaging (MPI) is a novel medical imaging modality, based on the magnetization of the superparamagnetic iron oxide nanoparticles. In MPI, an external magnetic field called the drive field is applied to excite the nanoparticles. The link between the image quality and the drive field parameters is complex, as nanoparticle behavior changes with the drive field parameters. In addition, the maximum applicable drive field strength is limited by human safety restrictions. Recent studies have shown that the resolution improves at low drive field amplitudes and SNR enhances as drive field frequency increases. Other studies have confirmed that scanning at frequencies as high as 150 kHz is feasible for human-size MPI scanners. However, how the image quality is affected by drive field parameters, especially for high frequencies around 150 kHz, was not investigated. This thesis investigates the effects of the drive field parameters on the image quality in MPI with relaxometer experiments. The effects of the safety limits are also explored across different drive field frequencies via simulations. The results provide important insight in determining the optimal drive field parameters for safe MPI scanners. This thesis also introduces a new method for improving the image quality in MPI. MPI images can suffer from asymmetric hazing and irregular trending artifacts when nanoparticle response is delayed due to relaxation effects. This thesis proposes a new method based on averaging of relaxation effects from negative and positive half-cycles of the MPI signal, combined with a Savitzky-Golay detrending filter. Both experimental and simulation results demonstrate a significant improvement in image quality.en_US
dc.description.degreeM.S.en_US
dc.description.statementofresponsibilityby Ecem Bozkurt.en_US
dc.embargo.release2021-01-24
dc.format.extentxiv, 63 leaves : illustrations (some color), color ; 30 cmen_US
dc.identifier.itemidB157529
dc.identifier.urihttp://hdl.handle.net/11693/35747
dc.language.isoEnglishen_US
dc.publisherBilkent Universityen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectMagnetic Particle Imagingen_US
dc.subjectDrive Field Parametersen_US
dc.subjectImage Reconstructionen_US
dc.subjectMagnetic Field Safety Limitsen_US
dc.titleEffects of scanning and reconstruction parameters on image quality in magnetic particle imagingen_US
dc.title.alternativeTarama ve geriçatım parametrelerinin manyetik parçacık görüntülemede görüntü kalitesine etkilerien_US
dc.typeThesisen_US

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