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[{"key": "dc.contributor.advisor", "value": "Miettinen, Arttu", "language": "", "element": "contributor", "qualifier": "advisor", "schema": "dc"}, {"key": "dc.contributor.advisor", "value": "Yliharju, Janne", "language": "", "element": "contributor", "qualifier": "advisor", "schema": "dc"}, {"key": "dc.contributor.author", "value": "Lyytinen, Tommi", "language": "", "element": "contributor", "qualifier": "author", "schema": "dc"}, {"key": "dc.date.accessioned", "value": "2021-09-28T06:27:22Z", "language": null, "element": "date", "qualifier": "accessioned", "schema": "dc"}, {"key": "dc.date.available", "value": "2021-09-28T06:27:22Z", "language": null, "element": "date", "qualifier": "available", "schema": "dc"}, {"key": "dc.date.issued", "value": "2021", "language": "", "element": "date", "qualifier": "issued", "schema": "dc"}, {"key": "dc.identifier.uri", "value": "https://jyx.jyu.fi/handle/123456789/77936", "language": null, "element": "identifier", "qualifier": "uri", "schema": "dc"}, {"key": "dc.description.abstract", "value": "Iteratiiviset rekonstruktiomenetelm\u00e4t ovat nousseet varteenotettaviksi vaihtoehdoiksi analyyttisen rekonstruktion rinnalle r\u00f6ntgentomografiassa, jossa suodatettu takaisinprojektio (FBP) on ollut laajasti k\u00e4ytetyin rekonstruktiomenetelm\u00e4 viime vuosikymmenten aikana sen laskennallisen nopeutensa ansiosta. Tietokoneiden laskentatehon kasvaminen ja iteratiivisten menetelmien kehittyminen ovat konkretisoineet niiden k\u00e4ytt\u00f6mahdollisuudet eri r\u00f6ntgentomografian sovelluskohteissa. Erityisesti statistiset ja mallipohjaiset menetelm\u00e4t ovat osoittaneet kyky\u00e4 kuvata rekonstruktioprosessia FBP-menetelm\u00e4\u00e4 tarkemmin, mik\u00e4 on tehnyt mahdolliseksi laadukkaampien kuvien muodostamisen v\u00e4h\u00e4isemmill\u00e4 artefakteilla ja s\u00e4teilyannoksella.\n\nT\u00e4ss\u00e4 tutkielmassa tarkastellaan erilaisia algebrallisia, statistisia ja mallipohjaisia iteratiivisia rekonstruktiomenetelmi\u00e4 kirjallisuuskatsauksen muodossa. Tutkimusaineiston ja menetelmien teoreettisen taustan pohjalta tuodaan esille, kuinka iteratiivisilla menetetelmill\u00e4 voidaan rekonstruoida tarkempia kuvia v\u00e4h\u00e4isemmill\u00e4 artefakteilla sek\u00e4 pienemm\u00e4ll\u00e4 s\u00e4teilyannoksella samalla pit\u00e4en laskenta-ajan k\u00e4yt\u00e4nn\u00f6llisen\u00e4.", "language": "fi", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.abstract", "value": "Iterative reconstruction methods have become viable alternatives to the analytical reconstruction in x-ray computed tomography, where filtered back projection (FBP) has been the most widely used method in the past decades because of its computational speed. Increased computational power of current workstations and improvements in iterative methods have concretized their potential use in the different applications of computed tomography. Especially statistical and model-based methods have shown their ability to describe the reconstruction process in more detail than FBP-method which has made it possible to reconstruct higher quality images with less artifacts and at a lower radiation dose.\n\nThis thesis examines various algebraic, statistical and model-based iterative reconstruction methods in the form of a literature review. Based on the research material and the theoretical background of the methods, it is presented how the iterative methods can be used to reconstruct more accurate images with less artifacts as well as at a lower radiation dose while keeping the reconstruction time practical.", "language": "en", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Submitted by Paivi Vuorio (paelvuor@jyu.fi) on 2021-09-28T06:27:22Z\nNo. of bitstreams: 0", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Made available in DSpace on 2021-09-28T06:27:22Z (GMT). No. of bitstreams: 0\n Previous issue date: 2021", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.format.extent", "value": "44", "language": "", "element": "format", "qualifier": "extent", "schema": "dc"}, {"key": "dc.language.iso", "value": "fin", "language": null, "element": "language", "qualifier": "iso", "schema": "dc"}, {"key": "dc.rights", "value": "In Copyright", "language": "en", "element": "rights", "qualifier": null, "schema": "dc"}, {"key": "dc.subject.other", "value": "r\u00f6ntgentomografia", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "algebrallinen rekonstruktio", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "statistinen rekonstruktio", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "mallipohjainen rekonstruktio", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "artefaktit", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.title", "value": "Iteratiiviset rekonstruktiomenetelm\u00e4t r\u00f6ntgentomografiassa", "language": "", "element": "title", "qualifier": null, "schema": "dc"}, {"key": "dc.type", "value": "bachelor thesis", "language": null, "element": "type", "qualifier": null, "schema": "dc"}, {"key": "dc.identifier.urn", "value": "URN:NBN:fi:jyu-202109285004", "language": "", "element": "identifier", "qualifier": "urn", "schema": "dc"}, {"key": "dc.type.ontasot", "value": "Bachelor's thesis", "language": "en", "element": "type", "qualifier": "ontasot", "schema": "dc"}, {"key": "dc.type.ontasot", "value": "Kandidaatinty\u00f6", "language": "fi", "element": "type", "qualifier": "ontasot", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Matemaattis-luonnontieteellinen tiedekunta", "language": "fi", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Faculty of Sciences", "language": "en", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.department", "value": "Fysiikan laitos", "language": "fi", "element": "contributor", "qualifier": "department", "schema": "dc"}, {"key": "dc.contributor.department", "value": "Department of Physics", "language": "en", "element": "contributor", "qualifier": "department", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "Jyv\u00e4skyl\u00e4n yliopisto", "language": "fi", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "University of Jyv\u00e4skyl\u00e4", "language": "en", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.subject.discipline", "value": "Fysiikka", "language": "fi", "element": "subject", "qualifier": "discipline", "schema": "dc"}, {"key": "dc.subject.discipline", "value": "Physics", "language": "en", "element": "subject", "qualifier": "discipline", "schema": "dc"}, {"key": "yvv.contractresearch.funding", "value": "0", "language": "", "element": "contractresearch", "qualifier": "funding", "schema": "yvv"}, {"key": "dc.type.coar", "value": "http://purl.org/coar/resource_type/c_7a1f", "language": null, "element": "type", "qualifier": "coar", "schema": "dc"}, {"key": "dc.rights.accesslevel", "value": "openAccess", "language": null, "element": "rights", "qualifier": "accesslevel", "schema": "dc"}, {"key": "dc.type.publication", "value": "bachelorThesis", "language": null, "element": "type", "qualifier": "publication", "schema": "dc"}, {"key": "dc.subject.oppiainekoodi", "value": "4021", "language": "", "element": "subject", "qualifier": "oppiainekoodi", "schema": "dc"}, {"key": "dc.subject.yso", "value": "rekonstruktio", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "fysiikka", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "r\u00f6ntgenkuvaus", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "r\u00f6ntgens\u00e4teily", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "tomografia", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.rights.url", "value": "https://rightsstatements.org/page/InC/1.0/", "language": null, "element": "rights", "qualifier": "url", "schema": "dc"}]
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