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Estimation of Spatiotemporal Isotropic and Anisotropic Myocardial Stiffness using Magnetic Resonance Elastography: A Study in Heart Failure- [electronic resource]
Estimation of Spatiotemporal Isotropic and Anisotropic Myocardial Stiffness using Magnetic Resonance Elastography: A Study in Heart Failure- [electronic resource]
상세정보
- 자료유형
- 학위논문(국외)
- 자관 청구기호
- 기본표목-개인명
- 표제와 책임표시사항
- Estimation of Spatiotemporal Isotropic and Anisotropic Myocardial Stiffness using Magnetic Resonance Elastography: A Study in Heart Failure - [electronic resource] / Mazumder, Ria.
- 발행, 배포, 간사 사항
- 발행, 배포, 간사 사항
- 형태사항
- 1 online resource(314 p)
- 일반주기
- Source: Dissertation Abstracts International, Volume: 78-04(E), Section: B.
- 일반주기
- Advisers: Bradley Clymer; Arunark Kolipaka.
- 학위논문주기
- Thesis (Ph.D.)--The Ohio State University, 2016.
- 요약 등 주기
- 요약Heart failure (HF), a complex clinical syndrome that is characterized by abnormal cardiac structure and function; and has been identified as the new epidemic of the 21st century. Based on the left ventricular (LV) ejection fraction (EF), HF can be classified into two broad categories: HF with reduced EF (HFrEF) and HF with preserved EF (HF pEF). Both HFrEF and HFpEF are associated with alteration in myocardial stiffness (MS), and there is an extensively rich literature to support this relation. However, t0 date, MS is not widely used in the clinics for the diagnosis of HF precisely because of the absence of a clinically efficient tool to estimate MS.
- 요약 등 주기
- 요약Current clinical techniques used to measure MS are invasive in nature, provide global stiffness measurements and cannot assess the true intrinsic properties of the myocardium. Therefore, there is a need to non-invasively quantify MS for accurate diagnosis and prognosis of HF. In recent years, a non-invasive technique known as cardiac magnetic resonance elastography (cMRE) has been developed to estimate MS. However, most of the reported studies using cMRE have been performed on phantoms, animals and healthy volunteers and minimal literature recognizing the importance of cMRE in diagnosing disease conditions, especially with respect to HF is available.
- 요약 등 주기
- 요약Additionally the existing cMRE techniques assume that the waves are propagating in a uniform, infinite, homogenous, isotropic medium. However, such assumptions are violated in the heart since it bears a complex anisotropic (orthotropic) geometry; current cMRE techniques may not provide the true mechanical properties of the myocardium and instead provide only an effective estimate of MS.
- 요약 등 주기
- 요약The overall goal of this dissertation is to: i) implement the currently established cMRE technique in HF (both HFrEF and HF pEF) porcine models to validate MS as a diagnostic biomarker; ii) explore the scope of ex-vivo cardiac diffusion tensor imaging (DTI) in investigating myocardial architecture (required for anisotropic stiffness measurements) in a HF causing diseased model; iii) develop waveguide cMRE inversion (a tool to estimate anisotropic stiffness) and validate the algorithm using finite element (FE) simulations; and iv) implement waveguide cMRE inversion in a hypertensive heart model (that has the potential to trigger HFpEF) to demonstrate the feasibility of measuring anisotropic MS in HF causing disease conditions.
- 요약 등 주기
- 요약From the results obtained it was observed that MS in a hypertensive heart (HFpEF causing condition) increased progressively with disease progression when compared to a normal heart; and this increase exhibited significant correlation with left ventricular pressure (increases due to hypertension) and thickness (increases secondary to hypertension). Additionally, MS demonstrated progressive focal increase in an infarcted myocardium (HFrEF causing condition) compared to non-infarcted remote myocardium with disease progression and the increase in MS exhibited significant correlation with i) mechanical testing-derived MS, ii) circumferential end-diastolic strain, iii) T1 values and iv) extra-cellular volume fraction.
- 요약 등 주기
- 요약The next part of the dissertation investigates the change in cardiac geometry (essential for investigating anisotropic elastic properties) as a result of myocardial infarction (HFrEF causing condition) in formalin-fixed ex-vivo specimens using DTI. Since in-vivo DTI is very complex (due to cardiac and respiratory motion) and is still in its inception, formalin-fixed ex-vivo specimens were used for the preliminary investigation. Hence it was essential to ensure whether the alterations observed in cardiac geometry were related to pathology or if it was an effect of the fixation process. The results demonstrated that formalin-fixation did not alter the structural orientation of the fibers and that fibers in the infarcted myocardium were shorter and disarrayed. Additionally, a post processing filter was developed to reduce acquisition time in cardiac DTI, thereby assisting in faster imaging. The filter was implemented on formalin-fixed ex-vivo myocardial infarction (HFrEF causing condition) induced porcine hearts to demonstrate that the technique preserved subtle pathological alterations in myocardial structure.
- 요약 등 주기
- 요약The last section of this dissertation validates the waveguide MRE inversion algorithm and demonstrates its feasibility in a hypertensive heart model. From the results it was observed that the inversion successfully resolved the anisotropic elastic properties of the materials in majority of the directions. The inversion failed in one shear direction because with the current actuation and geometric setting that particular mode was not being excited. Additionally, the anisotropic elastic coefficients estimated in the hypertensive heart model that is prone to triggering HFpEF demonstrated significant increase in one compressional direction and all three shear directions. In conclusion, this dissertation uses cMRE to demonstrate the potential of spatiotemporal isotropic and anisotropic myocardial stiffness as a diagnostic metric in heart failure porcine models.
- 주제명부출표목-일반주제명
- 주제명부출표목-일반주제명
- 주제명부출표목-일반주제명
- 주제명부출표목-일반주제명
- 주제명부출표목-일반주제명
- 부출표목-단체명
- 기본자료저록
- Dissertation Abstracts International. 78-04B(E).
- 기본자료저록
- Dissertation Abstract International
- 전자적 위치 및 접속
- 원문정보보기
- 소장사항
-
20180515 2018
MARC
008180601s2016 us esm 001c eng■001MOKWON01261035
■00520180518092919
■007cr
■020 ▼a9781369371215
■035 ▼a(MiAaPQ)AAI10294721
■035 ▼a(MiAaPQ)OhioLINK:osu1461230824
■040 ▼aMiAaPQ▼cMiAaPQ
■090 ▼a전자도서(박사논문)
■1001 ▼aMazumder, Ria.
■24510▼aEstimation of Spatiotemporal Isotropic and Anisotropic Myocardial Stiffness using Magnetic Resonance Elastography: A Study in Heart Failure▼h[electronic resource]▼cMazumder, Ria.
■260 ▼a[Sl]▼bThe Ohio State University▼c2016
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2016
■300 ▼a1 online resource(314 p)
■500 ▼aSource: Dissertation Abstracts International, Volume: 78-04(E), Section: B.
■500 ▼aAdvisers: Bradley Clymer; Arunark Kolipaka.
■5021 ▼aThesis (Ph.D.)--The Ohio State University, 2016.
■520 ▼aHeart failure (HF), a complex clinical syndrome that is characterized by abnormal cardiac structure and function; and has been identified as the new epidemic of the 21st century. Based on the left ventricular (LV) ejection fraction (EF), HF can be classified into two broad categories: HF with reduced EF (HFrEF) and HF with preserved EF (HF pEF). Both HFrEF and HFpEF are associated with alteration in myocardial stiffness (MS), and there is an extensively rich literature to support this relation. However, t0 date, MS is not widely used in the clinics for the diagnosis of HF precisely because of the absence of a clinically efficient tool to estimate MS.
■520 ▼aCurrent clinical techniques used to measure MS are invasive in nature, provide global stiffness measurements and cannot assess the true intrinsic properties of the myocardium. Therefore, there is a need to non-invasively quantify MS for accurate diagnosis and prognosis of HF. In recent years, a non-invasive technique known as cardiac magnetic resonance elastography (cMRE) has been developed to estimate MS. However, most of the reported studies using cMRE have been performed on phantoms, animals and healthy volunteers and minimal literature recognizing the importance of cMRE in diagnosing disease conditions, especially with respect to HF is available.
■520 ▼aAdditionally the existing cMRE techniques assume that the waves are propagating in a uniform, infinite, homogenous, isotropic medium. However, such assumptions are violated in the heart since it bears a complex anisotropic (orthotropic) geometry; current cMRE techniques may not provide the true mechanical properties of the myocardium and instead provide only an effective estimate of MS.
■520 ▼aThe overall goal of this dissertation is to: i) implement the currently established cMRE technique in HF (both HFrEF and HF pEF) porcine models to validate MS as a diagnostic biomarker; ii) explore the scope of ex-vivo cardiac diffusion tensor imaging (DTI) in investigating myocardial architecture (required for anisotropic stiffness measurements) in a HF causing diseased model; iii) develop waveguide cMRE inversion (a tool to estimate anisotropic stiffness) and validate the algorithm using finite element (FE) simulations; and iv) implement waveguide cMRE inversion in a hypertensive heart model (that has the potential to trigger HFpEF) to demonstrate the feasibility of measuring anisotropic MS in HF causing disease conditions.
■520 ▼aFrom the results obtained it was observed that MS in a hypertensive heart (HFpEF causing condition) increased progressively with disease progression when compared to a normal heart; and this increase exhibited significant correlation with left ventricular pressure (increases due to hypertension) and thickness (increases secondary to hypertension). Additionally, MS demonstrated progressive focal increase in an infarcted myocardium (HFrEF causing condition) compared to non-infarcted remote myocardium with disease progression and the increase in MS exhibited significant correlation with i) mechanical testing-derived MS, ii) circumferential end-diastolic strain, iii) T1 values and iv) extra-cellular volume fraction.
■520 ▼aThe next part of the dissertation investigates the change in cardiac geometry (essential for investigating anisotropic elastic properties) as a result of myocardial infarction (HFrEF causing condition) in formalin-fixed ex-vivo specimens using DTI. Since in-vivo DTI is very complex (due to cardiac and respiratory motion) and is still in its inception, formalin-fixed ex-vivo specimens were used for the preliminary investigation. Hence it was essential to ensure whether the alterations observed in cardiac geometry were related to pathology or if it was an effect of the fixation process. The results demonstrated that formalin-fixation did not alter the structural orientation of the fibers and that fibers in the infarcted myocardium were shorter and disarrayed. Additionally, a post processing filter was developed to reduce acquisition time in cardiac DTI, thereby assisting in faster imaging. The filter was implemented on formalin-fixed ex-vivo myocardial infarction (HFrEF causing condition) induced porcine hearts to demonstrate that the technique preserved subtle pathological alterations in myocardial structure.
■520 ▼aThe last section of this dissertation validates the waveguide MRE inversion algorithm and demonstrates its feasibility in a hypertensive heart model. From the results it was observed that the inversion successfully resolved the anisotropic elastic properties of the materials in majority of the directions. The inversion failed in one shear direction because with the current actuation and geometric setting that particular mode was not being excited. Additionally, the anisotropic elastic coefficients estimated in the hypertensive heart model that is prone to triggering HFpEF demonstrated significant increase in one compressional direction and all three shear directions. In conclusion, this dissertation uses cMRE to demonstrate the potential of spatiotemporal isotropic and anisotropic myocardial stiffness as a diagnostic metric in heart failure porcine models.
■590 ▼aSchool code: 0168.
■650 4▼aElectrical engineering
■650 4▼aBiomedical engineering
■650 4▼aBiomechanics
■650 4▼aMedical imaging
■650 4▼aComputer engineering
■690 ▼a0544
■690 ▼a0541
■690 ▼a0648
■690 ▼a0574
■690 ▼a0464
■71020▼aThe Ohio State University▼bElectrical and Computer Engineering.
■7730 ▼tDissertation Abstracts International▼g78-04B(E).
■773 ▼tDissertation Abstract International
■790 ▼a0168
■791 ▼aPh.D.
■792 ▼a2016
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T14820790▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
■980 ▼a20180515▼f2018
