DOI
https://doi.org/10.25772/THF1-1791
Author ORCID Identifier
0000-0002-2359-4361
Defense Date
2022
Document Type
Thesis
Degree Name
Doctor of Philosophy
Department
Mechanical and Nuclear Engineering
First Advisor
Joao S. Soares, Ph.D.
Abstract
Inverse modeling in cardiovascular medicine is a collection of methodologies that can provide non-invasive patient-specific estimations of clinical risk factors using medical imaging as inputs. Its incorporation into clinical practice has the potential to improve diagnosis and treatment planning with low associated risks and costs.
Herein, three different phase contrast magnetic resonance imaging (MRI) modalities were implemented as input data, displacement encoding with stimulated echoes (DENSE MRI) applied, and time-resolved velocity encoding phase-contrast MRI, in 1D and 3D, applied to pulmonary artery (PA) hemodynamics.
A model to account for the effect of periaortic interactions due to static and dynamic structures was embedded into an inverse finite element algorithm using in vivo displacements from DENSE MRI as target data. Results show that an energy source acting on the adventitia was required to reproduce the aortic motion at the vicinity of the heart, but not at the abdomen. The mean load acting on the adventitia was found to increase with age and to decrease along the descending aorta, from of the luminal pressure-pulse at the DAA, to at the DTA, and at the IAA, which may play a role on site specific vascular diseases.
Velocity-encoding MRI were retrospectively collected from PA hypertensive patients undergoing acute vasodilator challenges. The effect of the acute vasodilator on image-derived hemodynamic biomarkers was explored. Results suggests that inhaled Nitric Oxide (iNO) treatment affects the occurrence, timing and intensity of retrograde flow, while reducing pulse-wave velocity, as potential MRI-derived indicators of vasoreactivity.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
7-19-2022
Included in
Biomechanical Engineering Commons, Biomechanics and Biotransport Commons, Cardiology Commons, Computer-Aided Engineering and Design Commons, Medical Biomathematics and Biometrics Commons, Other Analytical, Diagnostic and Therapeutic Techniques and Equipment Commons, Radiology Commons