{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/90809"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/90809","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Distortion correction in magnetic resonance imaging using the simulated point spread function","abstract":"Geometric distortion is a highly prevalent issue for echo-planar imaging (EPI), due to long readout times and field inhomogeneity. Previously, the measured point spread function (PSF) has been shown to be effective in correcting this distortion. In this work, we reconstruct an image quickly and address the distortion with a point spread function that was generated entirely through simulation using the trajectory and measured field map. The distortion correction with this approach is shown to be better than k-space based iterative reconstructions and is robust to high differentials in magnetic field maps when we use an optimal trajectory. In addition, this technique is well-suited to parallel implementation, as the system matrix used is sparse.","abstract_html":"Geometric distortion is a highly prevalent issue for echo-planar imaging (EPI), due to long readout times and field inhomogeneity. Previously, the measured point spread function (PSF) has been shown to be effective in correcting this distortion. In this work, we reconstruct an image quickly and address the distortion with a point spread function that was generated entirely through simulation using the trajectory and measured field map. The distortion correction with this approach is shown to be better than k-space based iterative reconstructions and is robust to high differentials in magnetic field maps when we use an optimal trajectory. In addition, this technique is well-suited to parallel implementation, as the system matrix used is sparse.","abstract_has_math":false,"creators":["LaBelle, Genevieve Marie"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Electrical & Computer Engr","degree_department":null,"school":null,"contributors":["Sutton, Brad P."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-07-07T20:27:54Z","date_published":"2016-07-07T20:27:54Z","updated_at":"2026-07-22T22:26:34Z","subjects":["magnetic resonance imaging","point spread function","distortion","distortion correction","field inhomogeneity"],"languages":["en"],"rights":["Copyright 2016 Genevieve LaBelle"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/90809","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Sutton, Brad P."]},{"key":"dc:creator","label":"Author","values":["LaBelle, Genevieve Marie"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2016-07-07T20:27:54Z","2018-07-08T09:15:20Z","2016-04-26","2016-05"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical & Computer Engr"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["magnetic resonance imaging","point spread function","distortion","distortion correction","field inhomogeneity"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2016 Genevieve LaBelle"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/90809"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Geometric distortion is a highly prevalent issue for echo-planar imaging (EPI), due to long readout times and field inhomogeneity. 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