{"id":{"repo_id":"kings","oai_identifier":"oai:kclpure.kcl.ac.uk:studenttheses/f6a945d7-3a8e-4458-91c8-377ce3202119"},"canonical_url":"https://search.dev.ndltd.org/etd/kings/oai:kclpure.kcl.ac.uk:studenttheses/f6a945d7-3a8e-4458-91c8-377ce3202119","repository":{"repo_id":"kings","name":"King's College London","base_url":"https://kclpure.kcl.ac.uk/ws/oai"},"display":{"title":"Full 3D Blood Velocity Mapping and Flow Quantification from Doppler Echocardiographic Images","abstract":"This thesis contributes to knowledge by describing two novel methods to calculate
3D blood velocity and flow within the heart using 3D colour Doppler images. The
principal goal of both methods was to overcome the main limitation of Doppler
systems which is that the Doppler effect only measures one component of the velocity
(parallel to the beam direction). For that reason, measured velocity and calculated
flow depend on the angle between the beam direction and the flow.
The first method was developed to reconstruct 3D intracardiac velocity vector
fields. This is the first time that such vector fields have been obtained from 3D
colour Doppler images. The novelty of the proposal lies not only in the 3D velocity
reconstruction, but also 1) a new noise model for colour Doppler images was proposed
which improves the realism of simulation studies, 2) an efficient patch-wise
implementation was introduced and 3) ventricle wall motion was used to enable
full ventricular coverage. Based on simulations minimum acquisition requirements
for accurate reconstruction were established. These requirements were: view angles
over 20 degrees and noise below 10% of the Doppler maximum velocity. The
method was tested on healthy volunteers and on paediatric patients and an accuracy
of 15% compared to flow Magnetic Resonance Imaging (MRI) was obtained, when
acquisition and data conditions were close to the optimum range.
The second method proposes an algorithm to calculate angle-independent flow
rates through surfaces within the heart and vessels. Built on the Gauss’s theorem,
this method enables to increase coverage beyond the Field of View (FoV) of individual
colour Doppler images by combining images acquired from multiple views. The
method was validated in patients with Hypoplastic Left Heart Syndrome. Results
were compared with the current clinical gold standard measurement of flow MRI,
agreeing on flow values and volumes to less than 10%.
The novel methods proposed in this thesis have shown encouraging results using
volunteer and patient data. I hope that the methods proposed will in the future be
able to offer advanced flow measurements using echo. The ability to improve the
information available from echo imaging, due to its ease of use and cost effective
nature, has the potential for widespread improvements in clinical care.","abstract_html":"This thesis contributes to knowledge by describing two novel methods to calculate<br/>3D blood velocity and flow within the heart using 3D colour Doppler images. The<br/>principal goal of both methods was to overcome the main limitation of Doppler<br/>systems which is that the Doppler effect only measures one component of the velocity<br/>(parallel to the beam direction). For that reason, measured velocity and calculated<br/>flow depend on the angle between the beam direction and the flow.<br/>The first method was developed to reconstruct 3D intracardiac velocity vector<br/>fields. This is the first time that such vector fields have been obtained from 3D<br/>colour Doppler images. The novelty of the proposal lies not only in the 3D velocity<br/>reconstruction, but also 1) a new noise model for colour Doppler images was proposed<br/>which improves the realism of simulation studies, 2) an efficient patch-wise<br/>implementation was introduced and 3) ventricle wall motion was used to enable<br/>full ventricular coverage. Based on simulations minimum acquisition requirements<br/>for accurate reconstruction were established. These requirements were: view angles<br/>over 20 degrees and noise below 10% of the Doppler maximum velocity. The<br/>method was tested on healthy volunteers and on paediatric patients and an accuracy<br/>of 15% compared to flow Magnetic Resonance Imaging (MRI) was obtained, when<br/>acquisition and data conditions were close to the optimum range.<br/>The second method proposes an algorithm to calculate angle-independent flow<br/>rates through surfaces within the heart and vessels. Built on the Gauss’s theorem,<br/>this method enables to increase coverage beyond the Field of View (FoV) of individual<br/>colour Doppler images by combining images acquired from multiple views. The<br/>method was validated in patients with Hypoplastic Left Heart Syndrome. Results<br/>were compared with the current clinical gold standard measurement of flow MRI,<br/>agreeing on flow values and volumes to less than 10%.<br/>The novel methods proposed in this thesis have shown encouraging results using<br/>volunteer and patient data. I hope that the methods proposed will in the future be<br/>able to offer advanced flow measurements using echo. The ability to improve the<br/>information available from echo imaging, due to its ease of use and cost effective<br/>nature, has the potential for widespread improvements in clinical care.","abstract_has_math":false,"creators":["Gomez, Alberto"],"institution":"King's College London","degree_name":"Doctor of Philosophy","degree_level":"Doctoral Thesis","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Schaeffter, Tobias Richard","Penney, Graeme Patrick"],"committee_chairs":[],"committee_members":[],"year":2013,"date_issued":"2013-12-1","date_published":"2013-12-1","updated_at":"2026-07-24T02:44:31Z","subjects":["Echo","Doppler","Flow","3D echo"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:kclpure.kcl.ac.uk:studenttheses/f6a945d7-3a8e-4458-91c8-377ce3202119"],"render_values":[{"text":"oai:kclpure.kcl.ac.uk:studenttheses/f6a945d7-3a8e-4458-91c8-377ce3202119","href":null,"code":true}]}]},"links":{"outbound_url":"https://kclpure.kcl.ac.uk/portal/en/studentTheses/f6a945d7-3a8e-4458-91c8-377ce3202119","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Schaeffter, Tobias Richard","Penney, Graeme Patrick"]},{"key":"dc:creator","label":"Author","values":["Gomez, Alberto"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2013-12-1"]},{"key":"dc:date.issued","label":"Date","values":["2013-12-1"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Biomedical Engineering Department"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["King's College London"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://kclpure.kcl.ac.uk/portal/en/studentTheses/f6a945d7-3a8e-4458-91c8-377ce3202119"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral Thesis"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Doctor of Philosophy"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Echo","Doppler","Flow","3D echo"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:kclpure.kcl.ac.uk:studenttheses/f6a945d7-3a8e-4458-91c8-377ce3202119","https://kclpure.kcl.ac.uk/portal/en/studentTheses/f6a945d7-3a8e-4458-91c8-377ce3202119"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://kclpure.kcl.ac.uk/portal/files/12144005/Studentthesis-Alberto_Gomez_2013.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This thesis contributes to knowledge by describing two novel methods to calculate
3D blood velocity and flow within the heart using 3D colour Doppler images. The
principal goal of both methods was to overcome the main limitation of Doppler
systems which is that the Doppler effect only measures one component of the velocity
(parallel to the beam direction). For that reason, measured velocity and calculated
flow depend on the angle between the beam direction and the flow.
The first method was developed to reconstruct 3D intracardiac velocity vector
fields. This is the first time that such vector fields have been obtained from 3D
colour Doppler images. The novelty of the proposal lies not only in the 3D velocity
reconstruction, but also 1) a new noise model for colour Doppler images was proposed
which improves the realism of simulation studies, 2) an efficient patch-wise
implementation was introduced and 3) ventricle wall motion was used to enable
full ventricular coverage. Based on simulations minimum acquisition requirements
for accurate reconstruction were established. These requirements were: view angles
over 20 degrees and noise below 10% of the Doppler maximum velocity. The
method was tested on healthy volunteers and on paediatric patients and an accuracy
of 15% compared to flow Magnetic Resonance Imaging (MRI) was obtained, when
acquisition and data conditions were close to the optimum range.
The second method proposes an algorithm to calculate angle-independent flow
rates through surfaces within the heart and vessels. Built on the Gauss’s theorem,
this method enables to increase coverage beyond the Field of View (FoV) of individual
colour Doppler images by combining images acquired from multiple views. The
method was validated in patients with Hypoplastic Left Heart Syndrome. Results
were compared with the current clinical gold standard measurement of flow MRI,
agreeing on flow values and volumes to less than 10%.
The novel methods proposed in this thesis have shown encouraging results using
volunteer and patient data. I hope that the methods proposed will in the future be
able to offer advanced flow measurements using echo. The ability to improve the
information available from echo imaging, due to its ease of use and cost effective
nature, has the potential for widespread improvements in clinical care."]},{"key":"dc:title","label":"Title","values":["Full 3D Blood Velocity Mapping and Flow Quantification from Doppler Echocardiographic Images"]}]}],"canonical_facts":{"dc:contributor.advisor":["Schaeffter, Tobias Richard","Penney, Graeme Patrick"],"dc:creator":["Gomez, Alberto"],"dc:date":["2013-12-1"],"dc:date.issued":["2013-12-1"],"dc:description.abstract":["This thesis contributes to knowledge by describing two novel methods to calculate
3D blood velocity and flow within the heart using 3D colour Doppler images. The
principal goal of both methods was to overcome the main limitation of Doppler
systems which is that the Doppler effect only measures one component of the velocity
(parallel to the beam direction). For that reason, measured velocity and calculated
flow depend on the angle between the beam direction and the flow.
The first method was developed to reconstruct 3D intracardiac velocity vector
fields. This is the first time that such vector fields have been obtained from 3D
colour Doppler images. The novelty of the proposal lies not only in the 3D velocity
reconstruction, but also 1) a new noise model for colour Doppler images was proposed
which improves the realism of simulation studies, 2) an efficient patch-wise
implementation was introduced and 3) ventricle wall motion was used to enable
full ventricular coverage. Based on simulations minimum acquisition requirements
for accurate reconstruction were established. These requirements were: view angles
over 20 degrees and noise below 10% of the Doppler maximum velocity. The
method was tested on healthy volunteers and on paediatric patients and an accuracy
of 15% compared to flow Magnetic Resonance Imaging (MRI) was obtained, when
acquisition and data conditions were close to the optimum range.
The second method proposes an algorithm to calculate angle-independent flow
rates through surfaces within the heart and vessels. Built on the Gauss’s theorem,
this method enables to increase coverage beyond the Field of View (FoV) of individual
colour Doppler images by combining images acquired from multiple views. The
method was validated in patients with Hypoplastic Left Heart Syndrome. Results
were compared with the current clinical gold standard measurement of flow MRI,
agreeing on flow values and volumes to less than 10%.
The novel methods proposed in this thesis have shown encouraging results using
volunteer and patient data. I hope that the methods proposed will in the future be
able to offer advanced flow measurements using echo. The ability to improve the
information available from echo imaging, due to its ease of use and cost effective
nature, has the potential for widespread improvements in clinical care."],"dc:identifier":["oai:kclpure.kcl.ac.uk:studenttheses/f6a945d7-3a8e-4458-91c8-377ce3202119","https://kclpure.kcl.ac.uk/portal/en/studentTheses/f6a945d7-3a8e-4458-91c8-377ce3202119"],"dc:identifier.uri":["https://kclpure.kcl.ac.uk/portal/files/12144005/Studentthesis-Alberto_Gomez_2013.pdf"],"dc:language":["eng"],"dc:publisher.department":["Biomedical Engineering Department"],"dc:publisher.institution":["King's College London"],"dc:relation.isreferencedby":["https://kclpure.kcl.ac.uk/portal/en/studentTheses/f6a945d7-3a8e-4458-91c8-377ce3202119"],"dc:subject":["Echo","Doppler","Flow","3D echo"],"dc:title":["Full 3D Blood Velocity Mapping and Flow Quantification from Doppler Echocardiographic Images"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral Thesis"],"dc:type.qualificationname":["Doctor of Philosophy"]},"updated_at":"2026-07-24T02:44:31Z"}