Optical Flow Based Extraction of Breathing Signal from Cone-Beam CT Projections

A Master of Science thesis in Biomedical Engineering by Shafiya Sabah entitled, “Optical Flow Based Extraction of Breathing Signal from Cone-Beam CT Projections”, submitted in May 2020. Thesis advisor is Dr. Salam Dhou. Soft copy is available (Thesis, Approval Signatures, Completion Certificate, and...

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Main Author: Sabah, Shafiya (author)
Format: doctoralThesis
Published: 2020
Subjects:
Online Access:http://hdl.handle.net/11073/16715
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author Sabah, Shafiya
author_facet Sabah, Shafiya
author_role author
dc.contributor.none.fl_str_mv Dhou, Salam
dc.creator.none.fl_str_mv Sabah, Shafiya
dc.date.none.fl_str_mv 2020-06-21T07:16:04Z
2020-06-21T07:16:04Z
2020-05
dc.format.none.fl_str_mv application/pdf
dc.identifier.none.fl_str_mv 35.232-2020.07
http://hdl.handle.net/11073/16715
dc.language.none.fl_str_mv en_US
dc.subject.none.fl_str_mv Lung cancer
Radiotherapy
CBCT
Motion vectors
Reconstruction
dc.title.none.fl_str_mv Optical Flow Based Extraction of Breathing Signal from Cone-Beam CT Projections
dc.type.none.fl_str_mv info:eu-repo/semantics/publishedVersion
info:eu-repo/semantics/doctoralThesis
description A Master of Science thesis in Biomedical Engineering by Shafiya Sabah entitled, “Optical Flow Based Extraction of Breathing Signal from Cone-Beam CT Projections”, submitted in May 2020. Thesis advisor is Dr. Salam Dhou. Soft copy is available (Thesis, Approval Signatures, Completion Certificate, and AUS Archives Consent Form).
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identifier_str_mv 35.232-2020.07
language_invalid_str_mv en_US
network_acronym_str aus
network_name_str aus
oai_identifier_str oai:repository.aus.edu:11073/16715
publishDate 2020
repository.mail.fl_str_mv
repository.name.fl_str_mv
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spelling Optical Flow Based Extraction of Breathing Signal from Cone-Beam CT ProjectionsSabah, ShafiyaLung cancerRadiotherapyCBCTMotion vectorsReconstructionA Master of Science thesis in Biomedical Engineering by Shafiya Sabah entitled, “Optical Flow Based Extraction of Breathing Signal from Cone-Beam CT Projections”, submitted in May 2020. Thesis advisor is Dr. Salam Dhou. Soft copy is available (Thesis, Approval Signatures, Completion Certificate, and AUS Archives Consent Form).Lung cancer continues to be the most common type of cancer worldwide. Radiotherapy is used to break tumor cells by application of radiation beams during cancer treatment. Adapting radiotherapy to respiratory movements has always been a major concern in thoracic and upper-abdomen radiotherapy. Thus, estimating the respiration induced organ motion has been widely studied. Respiratory motion can be estimated using external equipment that trace the chest motion during breathing or tracking of radio-opaque markers implanted surgically in the lungs. However, these techniques are either invasive or require external equipment. The objective of this thesis is to propose an image-based method to estimate the respiratory motion without the involvement of any external equipment or implanted markers. To achieve this objective optical flow was implemented to acquire dense motion vectors from sequence of cone beam CT projection images. Principal component analysis was then performed on the motion vectors to project data to a lower dimension while preserving the dataset motion trends. Extracted signal was sorted into phase bins followed by 4D-reconstruction using a single phase to eliminate the effect of breathing motion. Several experiments were conducted to gauge the feasibility of this study. The dataset comprised of three computer simulations of cone beam CT projections as well as three real datasets acquired under clinical settings. The computer simulated phantom datasets were generated to include different scenarios such as fast breathing, slow breathing and irregular breathing patterns. The average phase shift error for phantom dataset under fast breathing motion was 0.6 ± 0.66 projections, 0.4 ± 0.5 under slow breathing and 0.53 ± 0.51 under irregular breathing. For clinical datasets the average phase shift for patient 1 was observed to be 1.936 ± 0.734, 1.185 ± 0.781 for patient 2 and 1.537 ± 0.93 for patient 3. Four-dimensional CBCT reconstruction was performed for one phantom dataset. Reconstructed image had a peak signal to noise ratio of 45.75.College of EngineeringMultidisciplinary ProgramsMaster of Science in Biomedical Engineering (MSBME)Dhou, Salam2020-06-21T07:16:04Z2020-06-21T07:16:04Z2020-05info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisapplication/pdf35.232-2020.07http://hdl.handle.net/11073/16715en_USoai:repository.aus.edu:11073/167152025-06-26T12:27:37Z
spellingShingle Optical Flow Based Extraction of Breathing Signal from Cone-Beam CT Projections
Sabah, Shafiya
Lung cancer
Radiotherapy
CBCT
Motion vectors
Reconstruction
status_str publishedVersion
title Optical Flow Based Extraction of Breathing Signal from Cone-Beam CT Projections
title_full Optical Flow Based Extraction of Breathing Signal from Cone-Beam CT Projections
title_fullStr Optical Flow Based Extraction of Breathing Signal from Cone-Beam CT Projections
title_full_unstemmed Optical Flow Based Extraction of Breathing Signal from Cone-Beam CT Projections
title_short Optical Flow Based Extraction of Breathing Signal from Cone-Beam CT Projections
title_sort Optical Flow Based Extraction of Breathing Signal from Cone-Beam CT Projections
topic Lung cancer
Radiotherapy
CBCT
Motion vectors
Reconstruction
url http://hdl.handle.net/11073/16715