Author ORCID Identifier
Doctor of Philosophy
Mechanical and Nuclear Engineering
Joao S. Soares, Ph.D.
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.
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Available for download on Wednesday, July 19, 2023
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