{"id":{"repo_id":"heid-diss","oai_identifier":"oai:archiv.ub.uni-heidelberg.de:3239"},"canonical_url":"https://search.dev.ndltd.org/etd/heid-diss/oai:archiv.ub.uni-heidelberg.de:3239","repository":{"repo_id":"heid-diss","name":"Universität Heidelberg","base_url":"http://archiv.ub.uni-heidelberg.de/volltextserver/cgi/oai2"},"display":{"title":"Determination of Aortic Elasticity from MR- and CT- Images Using an Automatic Active Contour Model","abstract":"The possibility to monitor changes in aortic elasticity in humans has important applications for clinical trials predicting arterial diseases before they become morphologically apparent. The elasticity is usually quantified by compliance measurements. Therefore, the relative temporal change in vessel cross-sectional area through the cardiac cycle or alternatively, the pulse-wave velocity has to be determined. In this work we determined the compliance via 3 MR methods (FLASH, TrueFISP and pulse-wave) and additionally CT. We developed an algorithm for the automatic segmentation of the artery wall from MR and CT images. Thus, the reliable detection of the aortic cross sectional area over the entire heart cycle was possible for both MR and CT with a relative error of about 1% depending on image quality. The reliability of the method was evaluated by means of a CT phantom setup.","abstract_html":"The possibility to monitor changes in aortic elasticity in humans has important applications for clinical trials predicting arterial diseases before they become morphologically apparent. The elasticity is usually quantified by compliance measurements. Therefore, the relative temporal change in vessel cross-sectional area through the cardiac cycle or alternatively, the pulse-wave velocity has to be determined. In this work we determined the compliance via 3 MR methods (FLASH, TrueFISP and pulse-wave) and additionally CT. We developed an algorithm for the automatic segmentation of the artery wall from MR and CT images. Thus, the reliable detection of the aortic cross sectional area over the entire heart cycle was possible for both MR and CT with a relative error of about 1% depending on image quality. The reliability of the method was evaluated by means of a CT phantom setup.","abstract_has_math":false,"creators":["Krug, Roland"],"institution":"Universität Heidelberg","degree_name":null,"degree_level":"thesis.doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Schad, Lothar R."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2003,"date_issued":"2003-02-12","date_published":"2003-02-12","updated_at":"2026-07-24T02:29:25Z","subjects":[],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://www.ub.uni-heidelberg.de/archiv/3239","outbound_label":"Repository record","outbound_source":"source_url"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Schad, Lothar R."]},{"key":"dc:creator","label":"Author","values":["Krug, Roland"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:publisher","label":"Institution","values":["Universitätsbibliothek Heidelberg"]},{"key":"dc:type","label":"Dc Type","values":["doctoralThesis"]},{"key":"thesis:degree_level","label":"Degree Level","values":["thesis.doctoral"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Universität Heidelberg"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The possibility to monitor changes in aortic elasticity in humans has important applications for clinical trials predicting arterial diseases before they become morphologically apparent. The elasticity is usually quantified by compliance measurements. Therefore, the relative temporal change in vessel cross-sectional area through the cardiac cycle or alternatively, the pulse-wave velocity has to be determined. In this work we determined the compliance via 3 MR methods (FLASH, TrueFISP and pulse-wave) and additionally CT. We developed an algorithm for the automatic segmentation of the artery wall from MR and CT images. Thus, the reliable detection of the aortic cross sectional area over the entire heart cycle was possible for both MR and CT with a relative error of about 1% depending on image quality. The reliability of the method was evaluated by means of a CT phantom setup.","Die Bestimmung der Aortenelastizität ist ein wichtiges Hilfsmittel zur frühzeitigen Diagnose von Arterienerkrankungen. Die Elastizität wird gewöhnlich über Compliance-Messungen quantifiziert, dabei wird die relative Änderung des Gefäßquerschnitts während des Herzzyklus oder die Pulswellengeschwindigkeit des Blutes bestimmt. In dieser Arbeit wurde die Compliance mit 3 MR Methoden (FLASH, TrueFISP und Pulse-wave) und zusätzlich im CT bestimmt. Es wurde ein Algorithmus entwickelt, der die Aortenwand aus MR- und CT- Bildern automatisch segmentiert. Kleine Änderungen des Aortenquerschnitts während der Herzphase konnten mit einem relativen Fehler von 1%, abhängig von der Bildqualität, sowohl im MR als auch CT bestimmt werden. Die Zuverlässigkeit des Algorithmus wurde an einem CT Phantomsetup getestet."]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Determination of Aortic Elasticity from MR- and CT- Images Using an Automatic Active Contour Model","Bestimmung der Elastizität der Aorta aus MR- und CT- Bildern mittels eines automatischen Active Contour Modells"]}]}],"canonical_facts":{"dc:contributor":["Schad, Lothar R."],"dc:creator":["Krug, Roland"],"dc:description.abstract":["The possibility to monitor changes in aortic elasticity in humans has important applications for clinical trials predicting arterial diseases before they become morphologically apparent. The elasticity is usually quantified by compliance measurements. Therefore, the relative temporal change in vessel cross-sectional area through the cardiac cycle or alternatively, the pulse-wave velocity has to be determined. In this work we determined the compliance via 3 MR methods (FLASH, TrueFISP and pulse-wave) and additionally CT. We developed an algorithm for the automatic segmentation of the artery wall from MR and CT images. Thus, the reliable detection of the aortic cross sectional area over the entire heart cycle was possible for both MR and CT with a relative error of about 1% depending on image quality. The reliability of the method was evaluated by means of a CT phantom setup.","Die Bestimmung der Aortenelastizität ist ein wichtiges Hilfsmittel zur frühzeitigen Diagnose von Arterienerkrankungen. Die Elastizität wird gewöhnlich über Compliance-Messungen quantifiziert, dabei wird die relative Änderung des Gefäßquerschnitts während des Herzzyklus oder die Pulswellengeschwindigkeit des Blutes bestimmt. In dieser Arbeit wurde die Compliance mit 3 MR Methoden (FLASH, TrueFISP und Pulse-wave) und zusätzlich im CT bestimmt. Es wurde ein Algorithmus entwickelt, der die Aortenwand aus MR- und CT- Bildern automatisch segmentiert. Kleine Änderungen des Aortenquerschnitts während der Herzphase konnten mit einem relativen Fehler von 1%, abhängig von der Bildqualität, sowohl im MR als auch CT bestimmt werden. Die Zuverlässigkeit des Algorithmus wurde an einem CT Phantomsetup getestet."],"dc:format.medium":["application/pdf"],"dc:publisher":["Universitätsbibliothek Heidelberg"],"dc:title":["Determination of Aortic Elasticity from MR- and CT- Images Using an Automatic Active Contour Model","Bestimmung der Elastizität der Aorta aus MR- und CT- Bildern mittels eines automatischen Active Contour Modells"],"dc:type":["doctoralThesis"],"thesis:degree_level":["thesis.doctoral"],"thesis:institution_name":["Universität Heidelberg"]},"updated_at":"2026-07-24T02:29:25Z"}