{"id":{"repo_id":"dundee","oai_identifier":"oai:discovery.dundee.ac.uk:studenttheses/ce30ac7f-8d18-464d-bbe5-5e9329ff5ff2"},"canonical_url":"https://search.dev.ndltd.org/etd/dundee/oai:discovery.dundee.ac.uk:studenttheses/ce30ac7f-8d18-464d-bbe5-5e9329ff5ff2","repository":{"repo_id":"dundee","name":"University of Dundee","base_url":"https://discovery.dundee.ac.uk/ws/oai"},"display":{"title":"Microultrasound Imaging of Tissue Dysplasia","abstract":"The second most common cause of cancer deaths in the developed world is bowel cancer. Improving the ability to detect and classify lesions as early as possible, allows treatment earlier. The work presented in this thesis is structured around the following detailed aims:Development of high frequency, broadband µUS (micro-ultrasound) imaging transducers through optimization of ultra-thinning processes for lithium niobate (LNO) and fabrication of novel ‘mass-spring’ matching layers using carefully controlled vacuum deposition is demonstrated. The effectiveness of this technique was quantified by applying multiple matching layers to 3 mm diameter 45 MHz LNO µUS transducers using carefully controlled vacuum deposition. The bandwidth of single mass-spring layer µUS transducer was measured to be 46% with an insertion loss of 21 dB. The bandwidth and insertion loss of a multiple matching layer µUS transducer was measured to be 59% and 18 dB respectively. The values were compared with an unmatched transducer which had a bandwidth and insertion loss of 28% and 34 dB respectively. All the experimentally measured values were in agreement with unidimensional acoustic model predictions. µUS tools that can detect and measure microscopic changes in precancerous tissue using a mouse small bowel model with an oncogenic mutation was developed. µUS transducer was used to test the hypothesis that the intestinal tissue morphology of WT (wild type) and ApcMin/+ (adenomatous polyposis coli) diverges with progressing age intervals (60, 90 and 120 days) of mice. A high frequency ultrasound scanning system was designed and the experiments were performed ex vivo using a focused 45 MHz, f-# = 2.85, µUS transducer. The data collected by scanning was used to compute the backscatter coefficients (BSC) and acoustic impedance (Z) of WT and ApcMin/+ mice. The 2D and 3D ultrasound images showed that µUS detects polyps < 500 µm in the scan plane. The measured values of BSC and Z showed differences between normal and precancerous tissue. The differences detected in precancerous murine intestine and human tissue using µUS were correlated with high resolution 3D optical imaging. This novel approach may provide a powerful adjunct to screening endoscopy for improved identification and monitoring, allowing earlier treatment of otherwise undetectable lesions.","abstract_html":"The second most common cause of cancer deaths in the developed world is bowel cancer. Improving the ability to detect and classify lesions as early as possible, allows treatment earlier. The work presented in this thesis is structured around the following detailed aims:Development of high frequency, broadband µUS (micro-ultrasound) imaging transducers through optimization of ultra-thinning processes for lithium niobate (LNO) and fabrication of novel ‘mass-spring’ matching layers using carefully controlled vacuum deposition is demonstrated. The effectiveness of this technique was quantified by applying multiple matching layers to 3 mm diameter 45 MHz LNO µUS transducers using carefully controlled vacuum deposition. The bandwidth of single mass-spring layer µUS transducer was measured to be 46% with an insertion loss of 21 dB. The bandwidth and insertion loss of a multiple matching layer µUS transducer was measured to be 59% and 18 dB respectively. The values were compared with an unmatched transducer which had a bandwidth and insertion loss of 28% and 34 dB respectively. All the experimentally measured values were in agreement with unidimensional acoustic model predictions. µUS tools that can detect and measure microscopic changes in precancerous tissue using a mouse small bowel model with an oncogenic mutation was developed. µUS transducer was used to test the hypothesis that the intestinal tissue morphology of WT (wild type) and ApcMin/+ (adenomatous polyposis coli) diverges with progressing age intervals (60, 90 and 120 days) of mice. A high frequency ultrasound scanning system was designed and the experiments were performed ex vivo using a focused 45 MHz, f-# = 2.85, µUS transducer. The data collected by scanning was used to compute the backscatter coefficients (BSC) and acoustic impedance (Z) of WT and ApcMin/+ mice. The 2D and 3D ultrasound images showed that µUS detects polyps < 500 µm in the scan plane. The measured values of BSC and Z showed differences between normal and precancerous tissue. The differences detected in precancerous murine intestine and human tissue using µUS were correlated with high resolution 3D optical imaging. This novel approach may provide a powerful adjunct to screening endoscopy for improved identification and monitoring, allowing earlier treatment of otherwise undetectable lesions.","abstract_has_math":false,"creators":["Sharma, Srikanta"],"institution":"University of Dundee","degree_name":"Doctor of Medicine","degree_level":"Doctoral Thesis","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Nathke, Inke"],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015","date_published":"2015","updated_at":"2026-07-24T02:08:05Z","subjects":["Microultrasound","Tissue characterisation","Colon cancer","Matching layers","High frequency Ultrasound transducers"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:discovery.dundee.ac.uk:studenttheses/ce30ac7f-8d18-464d-bbe5-5e9329ff5ff2"],"render_values":[{"text":"oai:discovery.dundee.ac.uk:studenttheses/ce30ac7f-8d18-464d-bbe5-5e9329ff5ff2","href":null,"code":true}]}]},"links":{"outbound_url":"https://discovery.dundee.ac.uk/en/studentTheses/ce30ac7f-8d18-464d-bbe5-5e9329ff5ff2","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Nathke, Inke"]},{"key":"dc:contributor.sponsor","label":"Sponsor","values":["Royal Society of Edinburgh"]},{"key":"dc:creator","label":"Author","values":["Sharma, Srikanta"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015"]},{"key":"dc:date.issued","label":"Date","values":["2015"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Division of Imaging & Technology"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Dundee"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://discovery.dundee.ac.uk/en/studentTheses/ce30ac7f-8d18-464d-bbe5-5e9329ff5ff2"]},{"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 Medicine"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Microultrasound","Tissue characterisation","Colon cancer","Matching layers","High frequency Ultrasound transducers"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights.embargodate","label":"Dc Rights Embargodate","values":["2017-01-31"]},{"key":"dc:rights.embargoreason","label":"Dc Rights Embargoreason","values":["/dk/atira/pure/core/document/studentthesisembargoreason/commercialexploitation"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:discovery.dundee.ac.uk:studenttheses/ce30ac7f-8d18-464d-bbe5-5e9329ff5ff2","https://discovery.dundee.ac.uk/en/studentTheses/ce30ac7f-8d18-464d-bbe5-5e9329ff5ff2"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://discovery.dundee.ac.uk/files/7075211/Thesis_final_version.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The second most common cause of cancer deaths in the developed world is bowel cancer. Improving the ability to detect and classify lesions as early as possible, allows treatment earlier. The work presented in this thesis is structured around the following detailed aims:Development of high frequency, broadband µUS (micro-ultrasound) imaging transducers through optimization of ultra-thinning processes for lithium niobate (LNO) and fabrication of novel ‘mass-spring’ matching layers using carefully controlled vacuum deposition is demonstrated. The effectiveness of this technique was quantified by applying multiple matching layers to 3 mm diameter 45 MHz LNO µUS transducers using carefully controlled vacuum deposition. The bandwidth of single mass-spring layer µUS transducer was measured to be 46% with an insertion loss of 21 dB. The bandwidth and insertion loss of a multiple matching layer µUS transducer was measured to be 59% and 18 dB respectively. The values were compared with an unmatched transducer which had a bandwidth and insertion loss of 28% and 34 dB respectively. All the experimentally measured values were in agreement with unidimensional acoustic model predictions. µUS tools that can detect and measure microscopic changes in precancerous tissue using a mouse small bowel model with an oncogenic mutation was developed. µUS transducer was used to test the hypothesis that the intestinal tissue morphology of WT (wild type) and ApcMin/+ (adenomatous polyposis coli) diverges with progressing age intervals (60, 90 and 120 days) of mice. A high frequency ultrasound scanning system was designed and the experiments were performed ex vivo using a focused 45 MHz, f-# = 2.85, µUS transducer. The data collected by scanning was used to compute the backscatter coefficients (BSC) and acoustic impedance (Z) of WT and ApcMin/+ mice. The 2D and 3D ultrasound images showed that µUS detects polyps < 500 µm in the scan plane. The measured values of BSC and Z showed differences between normal and precancerous tissue. The differences detected in precancerous murine intestine and human tissue using µUS were correlated with high resolution 3D optical imaging. This novel approach may provide a powerful adjunct to screening endoscopy for improved identification and monitoring, allowing earlier treatment of otherwise undetectable lesions."]},{"key":"dc:title","label":"Title","values":["Microultrasound Imaging of Tissue Dysplasia"]}]}],"canonical_facts":{"dc:contributor.advisor":["Nathke, Inke"],"dc:contributor.sponsor":["Royal Society of Edinburgh"],"dc:creator":["Sharma, Srikanta"],"dc:date":["2015"],"dc:date.issued":["2015"],"dc:description.abstract":["The second most common cause of cancer deaths in the developed world is bowel cancer. Improving the ability to detect and classify lesions as early as possible, allows treatment earlier. The work presented in this thesis is structured around the following detailed aims:Development of high frequency, broadband µUS (micro-ultrasound) imaging transducers through optimization of ultra-thinning processes for lithium niobate (LNO) and fabrication of novel ‘mass-spring’ matching layers using carefully controlled vacuum deposition is demonstrated. The effectiveness of this technique was quantified by applying multiple matching layers to 3 mm diameter 45 MHz LNO µUS transducers using carefully controlled vacuum deposition. The bandwidth of single mass-spring layer µUS transducer was measured to be 46% with an insertion loss of 21 dB. The bandwidth and insertion loss of a multiple matching layer µUS transducer was measured to be 59% and 18 dB respectively. The values were compared with an unmatched transducer which had a bandwidth and insertion loss of 28% and 34 dB respectively. All the experimentally measured values were in agreement with unidimensional acoustic model predictions. µUS tools that can detect and measure microscopic changes in precancerous tissue using a mouse small bowel model with an oncogenic mutation was developed. µUS transducer was used to test the hypothesis that the intestinal tissue morphology of WT (wild type) and ApcMin/+ (adenomatous polyposis coli) diverges with progressing age intervals (60, 90 and 120 days) of mice. A high frequency ultrasound scanning system was designed and the experiments were performed ex vivo using a focused 45 MHz, f-# = 2.85, µUS transducer. The data collected by scanning was used to compute the backscatter coefficients (BSC) and acoustic impedance (Z) of WT and ApcMin/+ mice. The 2D and 3D ultrasound images showed that µUS detects polyps < 500 µm in the scan plane. The measured values of BSC and Z showed differences between normal and precancerous tissue. The differences detected in precancerous murine intestine and human tissue using µUS were correlated with high resolution 3D optical imaging. This novel approach may provide a powerful adjunct to screening endoscopy for improved identification and monitoring, allowing earlier treatment of otherwise undetectable lesions."],"dc:identifier":["oai:discovery.dundee.ac.uk:studenttheses/ce30ac7f-8d18-464d-bbe5-5e9329ff5ff2","https://discovery.dundee.ac.uk/en/studentTheses/ce30ac7f-8d18-464d-bbe5-5e9329ff5ff2"],"dc:identifier.uri":["https://discovery.dundee.ac.uk/files/7075211/Thesis_final_version.pdf"],"dc:language":["eng"],"dc:publisher.department":["Division of Imaging & Technology"],"dc:publisher.institution":["University of Dundee"],"dc:relation.isreferencedby":["https://discovery.dundee.ac.uk/en/studentTheses/ce30ac7f-8d18-464d-bbe5-5e9329ff5ff2"],"dc:rights.embargodate":["2017-01-31"],"dc:rights.embargoreason":["/dk/atira/pure/core/document/studentthesisembargoreason/commercialexploitation"],"dc:subject":["Microultrasound","Tissue characterisation","Colon cancer","Matching layers","High frequency Ultrasound transducers"],"dc:title":["Microultrasound Imaging of Tissue Dysplasia"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral Thesis"],"dc:type.qualificationname":["Doctor of Medicine"]},"updated_at":"2026-07-24T02:08:05Z"}