{"id":{"repo_id":"uwo","oai_identifier":"oai:uwo.scholaris.ca:20.500.14721/20256"},"canonical_url":"https://search.dev.ndltd.org/etd/uwo/oai:uwo.scholaris.ca:20.500.14721/20256","repository":{"repo_id":"uwo","name":"Western University","base_url":"https://uwo.scholaris.ca/server/oai/request"},"display":{"title":"IMPROVING RESOLUTION IN WRIST SPECT WITH CONVERGING COLLIMATORS AND CT ANATOMICAL PRIORS","abstract":"Wrist injuries account for over 750 000 visits to the hospital each year. Better imaging techniques are required to properly diagnose these injuries. Planar nuclear medicine offers a high sensitivity for fracture detection, but low specificity. Improving resolution could lead to better specificity. We hypothesize that wrist SPECT resolution can be improved by using pinhole collimators and by incorporating anatomical prior information. Phantom experiments have shown that a 3mm single-pinhole system can achieve a 4mm resolution at clinical count levels, but a 3mm resolution required 4-times as many counts. Computer simulations showed that by incorporating CT anatomical prior information a 4.6mm FWHM resolution was measured at 4 million counts, which is a 10% improvement to current iterative reconstruction techniques. These results demonstrated that pinhole collimation or CT prior information, which is now possible with SPECT/CT canneras can improve spatial resolution, however, current count levels are a limiting factor.","abstract_html":"Wrist injuries account for over 750 000 visits to the hospital each year. Better imaging techniques are required to properly diagnose these injuries. Planar nuclear medicine offers a high sensitivity for fracture detection, but low specificity. Improving resolution could lead to better specificity. We hypothesize that wrist SPECT resolution can be improved by using pinhole collimators and by incorporating anatomical prior information. Phantom experiments have shown that a 3mm single-pinhole system can achieve a 4mm resolution at clinical count levels, but a 3mm resolution required 4-times as many counts. Computer simulations showed that by incorporating CT anatomical prior information a 4.6mm FWHM resolution was measured at 4 million counts, which is a 10% improvement to current iterative reconstruction techniques. These results demonstrated that pinhole collimation or CT prior information, which is now possible with SPECT/CT canneras can improve spatial resolution, however, current count levels are a limiting factor.","abstract_has_math":false,"creators":["Sabondiian, Eric"],"institution":null,"degree_name":"M Sc","degree_level":null,"degree_discipline":"Medical Biophysics","degree_department":null,"school":null,"contributors":[],"advisors":["Wells, Glenn","Holdsworth, David","Stodilka, Robert"],"committee_chairs":[],"committee_members":[],"year":2006,"date_issued":"2006-01-01","date_published":"2006-01-01","updated_at":"2026-07-27T21:56:09Z","subjects":["SPECT","SPECT/CT","MAP-OSEM","CT anatomical priors","pinhole collimators","wrist imaging"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/20.500.14721/20256","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Wells, Glenn","Holdsworth, David","Stodilka, Robert"]},{"key":"dc:creator","label":"Author","values":["Sabondiian, Eric"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2025-06-25T19:19:33Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2025-06-25T19:19:33Z"]},{"key":"dc:date.issued","label":"Date","values":["2006-01-01"]},{"key":"dc:type","label":"Dc Type","values":["thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Medical Biophysics"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M Sc"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["SPECT","SPECT/CT","MAP-OSEM","CT anatomical priors","pinhole collimators","wrist imaging"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/20.500.14721/20256"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Wrist injuries account for over 750 000 visits to the hospital each year. Better imaging techniques are required to properly diagnose these injuries. Planar nuclear medicine offers a high sensitivity for fracture detection, but low specificity. Improving resolution could lead to better specificity. We hypothesize that wrist SPECT resolution can be improved by using pinhole collimators and by incorporating anatomical prior information. Phantom experiments have shown that a 3mm single-pinhole system can achieve a 4mm resolution at clinical count levels, but a 3mm resolution required 4-times as many counts. Computer simulations showed that by incorporating CT anatomical prior information a 4.6mm FWHM resolution was measured at 4 million counts, which is a 10% improvement to current iterative reconstruction techniques. These results demonstrated that pinhole collimation or CT prior information, which is now possible with SPECT/CT canneras can improve spatial resolution, however, current count levels are a limiting factor."]},{"key":"dc:title","label":"Title","values":["IMPROVING RESOLUTION IN WRIST SPECT WITH CONVERGING COLLIMATORS AND CT ANATOMICAL PRIORS"]}]}],"canonical_facts":{"dc:contributor.advisor":["Wells, Glenn","Holdsworth, David","Stodilka, Robert"],"dc:creator":["Sabondiian, Eric"],"dc:date.accessioned":["2025-06-25T19:19:33Z"],"dc:date.available":["2025-06-25T19:19:33Z"],"dc:date.issued":["2006-01-01"],"dc:description.abstract":["Wrist injuries account for over 750 000 visits to the hospital each year. Better imaging techniques are required to properly diagnose these injuries. Planar nuclear medicine offers a high sensitivity for fracture detection, but low specificity. Improving resolution could lead to better specificity. We hypothesize that wrist SPECT resolution can be improved by using pinhole collimators and by incorporating anatomical prior information. Phantom experiments have shown that a 3mm single-pinhole system can achieve a 4mm resolution at clinical count levels, but a 3mm resolution required 4-times as many counts. Computer simulations showed that by incorporating CT anatomical prior information a 4.6mm FWHM resolution was measured at 4 million counts, which is a 10% improvement to current iterative reconstruction techniques. These results demonstrated that pinhole collimation or CT prior information, which is now possible with SPECT/CT canneras can improve spatial resolution, however, current count levels are a limiting factor."],"dc:identifier.uri":["https://hdl.handle.net/20.500.14721/20256"],"dc:subject":["SPECT","SPECT/CT","MAP-OSEM","CT anatomical priors","pinhole collimators","wrist imaging"],"dc:title":["IMPROVING RESOLUTION IN WRIST SPECT WITH CONVERGING COLLIMATORS AND CT ANATOMICAL PRIORS"],"dc:type":["thesis"],"thesis:degree_discipline":["Medical Biophysics"],"thesis:degree_name":["M Sc"]},"updated_at":"2026-07-27T21:56:09Z"}